Co-reporter:
Journal of Separation Science 2017 Volume 40(Issue 5) pp:1107-1114
Publication Date(Web):2017/03/01
DOI:10.1002/jssc.201600780
Novel 3-aminophenylboronic acid functionalized poly(glycidyl methacrylate-co-ethylene dimethacrylate) microspheres were prepared for the solid-phase extraction of glycopeptides/glycoproteins. The adsorption efficiency, maximum adsorption capacity, and specific recognition of the microspheres to glycoprotein were investigated. The results indicated excellent adsorption of glycoproteins by the microspheres, which are attributed to the well-defined boronic acid brushes on the microsphere surfaces. Furthermore, a solid-phase extraction microcolumn filled with the microspheres was used to efficiently enrich glycopeptides from enzymatic hydrolysates from human serum samples. The mass spectrometry results demonstrated that the method is suitable for the separation and enrichment of glycopeptides/glycoproteins from complex biological samples.
Co-reporter:Rui-Ling Zhang, Si-Si Liang, Meng Jin, Tian He, Zhi-Qi Zhang
Sensors and Actuators B: Chemical 2017 Volume 253(Volume 253) pp:
Publication Date(Web):1 December 2017
DOI:10.1016/j.snb.2017.06.136
•Low-fluorescence GSH-AuNCs were first used for acetylcholinesterase assays.•Thiocholine effectively enhanced GSH-AuNCs fluorescence via AuS bond formation.•A simple, rapid, and sensitive fluorescence enhancement method was developed.A direct fluorescence turn-on method for simple and sensitive acetylcholinesterase (AChE) activity assay and AChE inhibitor screening has been developed by first using low-fluorescence glutathione-capped gold nanoclusters (GSH-AuNCs). The thiocholine produced by AChE-catalyzed hydrolysis of S-acetylthiocholine iodide could effectively enhance the fluorescence of GSH-AuNCs via AuS bond formation. In the presence of inhibitors, AChE activity was suppressed and thus fluorescence enhancement decreased. Therefore, AChE activity assay and inhibitor screening could be performed by measuring the fluorescence intensity of the system. The linear range of the AChE activity assay was 0–30 mU mL−1 with a limit of detection of 0.03 mU mL−1 (S/N = 3). The IC50 values of two inhibitors (tacrine and neostigmine bromide) were 42.92 nM and 37.04 nM, respectively. The developed protocol provides a simple and sensitive platform for assaying AChE activity and screening its inhibitors.
Co-reporter:Liang Qi, Zhe Yan, Yuan Huo, Xiao-Man Hai, Zhi-Qi Zhang
Biosensors and Bioelectronics 2017 Volume 87() pp:566-571
Publication Date(Web):15 January 2017
DOI:10.1016/j.bios.2016.08.093
•The utilization of MnO2 nanosheet in fluorescence polarization measurement.•Constructing a MnO2 nanosheet & ligand-DNA interaction-based biosensor.•Development of a novel fluorescence polarization biosensor for Ag+ detection.•Exploration of the mechanism underlying the fluorescence polarization change.Silver (Ag+) ions are highly toxic to aquatic organisms and accumulate in the human body via the food chain. Therefore, the development of sensitive and selective quantitative analytical methods for detecting trace amounts of these ions is necessary. In the present study, a MnO2 nanosheet-assisted, ligand-DNA interaction and fluorescence polarization-based method was developed, for the first time, for sensitive detection of Ag+. The addition of Ag+ to the preformed proflavine-DNA complex induced the release of proflavine, which elicited weak changes in fluorescence polarization. The subsequent addition of MnO2 nanosheets magnified the observed changes, making this a feasible method for the detection of Ag+. The calibration graphs indicated good linearity over the concentration ranges of 30–240 nM for Ag+, with a detection limit (S/N=3) of 9.1 nM. This method additionally exhibits high selectivity. The mechanism underlying the changes in fluorescence polarization caused by the addition of Ag+ in the presence of MnO2 nanosheets was further explored in this study. These findings demonstrate that the present MnO2 nanosheet-assisted fluorescence polarization biosensor may represent a promising tool for the detection of Ag+ ions. The results for practical detecting Ag+ proved that this biosensor can be applied to environmental water sample analysis.
Co-reporter:Jing Zhang;Tian He;Liang Tang;Zhi-Qi Zhang
Journal of Separation Science 2016 Volume 39( Issue 9) pp:1691-1699
Publication Date(Web):
DOI:10.1002/jssc.201500921
Glycoproteins are useful biomarkers and therapeutic targets for a number of diseases, including infections and cancer. However, identification and isolation of low-abundant glycoproteins remains a significant challenge that limits their application. Thus, methods of specific and selective glycoprotein enrichment are required. In this study, novel phenylboronic acid functionalized magnetic microspheres were successfully synthesized. Fe3O4 microspheres were synthesized by using a hydrothermal method and were coated with tetraethyl orthosilicate using an ultrasonic method to form a core-shell structure. Compared to the conventional mechanical stirring for 12 h, the ultrasonic method saved about 7 h in processing time, and the home-made magnetic microspheres had better dispersibility and homogeneity. Subsequently, the magnetic microspheres were modified by addition of an amino group and a carboxyl group, in sequence. Finally, 3-aminophenylboronic acid, as the functional monomer, was linked to the magnetic microspheres for capturing glycoprotein/glycopeptides. The results of this study indicate that phenylboronic acid functionalized magnetic microspheres show excellent adsorption performance toward glycoprotein/glycopeptides. The maximum absorbing capacity of the microspheres for fetuin was 108 mg/g, and the enrichment efficiency reached 89.7%, indicating their potential to separate and enrich glycoproteins from the complex biological samples.
Co-reporter:Yuan Huo, Liang Qi, Xiao-Jun Lv, Ting Lai, Jing Zhang, Zhi-Qi Zhang
Biosensors and Bioelectronics 2016 Volume 78() pp:315-320
Publication Date(Web):15 April 2016
DOI:10.1016/j.bios.2015.11.043
•The ATP-aptamer folding on the surface of unmodified AuNPs was first studied.•ATP-aptamer complexes could more effectively stabilize AuNPs than ATP or aptamer.•An ATP aptasensor was developed using label-free aptamers and unmodified AuNPs.•This aptasensor is highly sensitive and selective for ATP colorimetric detection.Adenosine triphosphate (ATP) is the most direct source of energy in organisms. This study is the first to demonstrate that ATP-aptamer complexes provide greater protection for unmodified gold nanoparticles (AuNPs) against salt-induced aggregation than either aptamer or ATP alone. This protective effect was confirmed using transmission electron microscopy, dynamic light scattering, Zeta potential measurement, and fluorescence polarization techniques. Utilizing controlled particle aggregation/dispersion as a gauge, a sensitive and selective aptasensor for colorimetric detection of ATP was developed using ATP-binding aptamers as the identification element and unmodified AuNPs as the probe. This aptasensor exhibited a good linear relationship between the absorbance and the logarithm concentration of ATP within a 50–1000 nM range. ATP analogs such as guanosine triphosphate, uridine triphosphate and cytidine triphosphate resulted in little or no interference in the determination of ATP.
Co-reporter:Liang Qi, Jing-Ru Wei, Xiao-Jun Lv, Yuan Huo, Zhi-Qi Zhang
Biosensors and Bioelectronics 2016 Volume 86() pp:287-292
Publication Date(Web):15 December 2016
DOI:10.1016/j.bios.2016.06.051
•A new small fluorescence ligand was found to interact with RRE at the Rev binding site.•The ratiometric fluorescence assay was first applied to monitor ligand-RNA interactions.•ICR 191 as a fluorescent indicator is potentially used to screen Rev antagonists.The Rev protein regulates HIV-1 gene expression. Small ligands that bind to the Rev response element (RRE) RNA would inhibit Rev function and suppress HIV-1 replication. A novel ratiometric fluorescence assay was applied in the present study to monitor ligand-RNA interactions by using red-emitting CdTe quantum dots (QDs) coated with silica as a reference. A small fluorescence ligand, ICR 191, was found to interact with RRE at the Rev binding site and compete with the Rev peptide. After adding red-emitting QDs to the interaction system, it was observed that ICR 191 did not fluoresce upon the addition of RRE, and fluorescence recovered when ICR 191 was displaced by a Rev model peptide, whereas the fluorescence of QDs remained constant. Furthermore, variations in the fluorescence ratios between ICR 191 and QDs were exploited to characterize the interactions of Rev with two known antagonists, neomycin B and tobramycin, by using RRE RNA with ICR 191 as a fluorescence indicator. Together, our results demonstrated that ratiometric fluorescence-based nanotechnology applications can be used for ligand−RNA interaction assays. This ICR 191-RRE RNA interaction assay can potentially be developed to build a screening model for assessing antagonists of the Rev binding element in RRE.
Co-reporter:Xian-Li Ge;Ting Shi;Huan Wang;Jing Zhang;Zhi-Qi Zhang
Food Analytical Methods 2016 Volume 9( Issue 12) pp:3319-3326
Publication Date(Web):2016 December
DOI:10.1007/s12161-016-0525-3
A novel method for protein extraction from sweet almonds with aqueous polyethylene glycol (PEG) as solvent and recovery from the extraction solution was developed. The extraction yields of different solvents, such as sodium hydroxide, sodium chloride, PEG 200, PEG 400, and PEG 600 aqueous solutions, were investigated and PEG 200 showed the highest extraction efficiency. The PEG-based microwave-assisted extraction (MAE) parameters were then optimized using response surface methodology. Under optimum condition, PEG 200 concentration of 25 % (w/w), liquid to solid ratio of 22 mL g−1, microwave power of 120 W, extraction temperature of 45 °C, and extraction time of 4 min, the average extraction yield was 93.75 ± 3.15 %. Subsequently, the almond protein was recovered from the extraction solution containing PEG with an isoelectric point-ethanol synergy precipitation protocol. The combined technique integrated the speed of isoelectric point precipitation with the completeness of alcohol precipitation. The recovery of almond protein was 98.81 % with a time of 3–5 min. The proposed PEG-based MAE and synergy precipitation protocol provide a rapid and effective method for almond protein extraction and recovery and have the potential to be used for other plant proteins.
Co-reporter:Si-Yao Liu;Huan Wang;Tian He;Liang Qi ;Zhi-Qi Zhang
Luminescence 2016 Volume 31( Issue 1) pp:96-101
Publication Date(Web):
DOI:10.1002/bio.2929
Abstract
A fluorescence method was established for a α-glucosidase activity assay and inhibitor screening based on β-cyclodextrin-coated quantum dots. p-Nitrophenol, the hydrolysis product of the α-glucosidase reaction, could quench the fluorescence of β-cyclodextrin-coated quantum dots via an electron transfer process, leading to fluorescence turn-off, whereas the fluorescence of the system turned on in the presence of α-glucosidase inhibitors. Taking advantage of the excellent properties of quantum dots, this method provided a very simple, rapid and sensitive screening method for α-glucosidase inhibitors. Two α-glucosidase inhibitors, 2,4,6-tribromophenol and acarbose, were used to evaluate the feasibility of this screening model, and IC50 values of 24 μM and 0.55 mM were obtained respectively, which were lower than those previously reported. The method may have potential application in screening α-glucosidase inhibitors. Copyright © 2015 John Wiley & Sons, Ltd.
Co-reporter:Xiang-Yu Gao;Rui-Lin Liu;Jin Ma;Han-Ying Zhan
Journal of Porous Materials 2016 Volume 23( Issue 1) pp:157-164
Publication Date(Web):2016 February
DOI:10.1007/s10934-015-0066-y
A combined dual-metal template method was used to prepare magnetic hierarchical porous carbon (MHPC). In this work, agar was selected as the carbon source and chelating agent, and Zn(NO3)2·6H2O and FeCl3 simultaneously served as the sources of the dual-metal center ions and as structure-directing agents. Zn2+ and Fe3+ ions were coordinated with agar via a chelate-assisted co-assembly route. The mixture was subsequently converted into an iron–zinc–carbon composite. Finally, the as-prepared composite was calcined to form MHPC. X-ray powder diffraction demonstrated the existence of α-Fe in the MHPC, and the magnetic properties of MHPC were determined to be 84.1 emu/g. Nitrogen adsorption measurements revealed that MHPC had a high surface area of 764.54 m2/g, and a total pore volume of 0.61 cm3/g. The adsorption test results indicated that MHPC has a high adsorption capacity for 4-nitrophenol (227.27 mg/g) and that it is easy to isolate from aqueous solution under the assistance of an external magnetic field.
Co-reporter:Xiao-Jun Lv, Liang Qi, Xiang-Yu Gao, Huan Wang, Yuan Huo, Zhi-Qi Zhang
Talanta 2016 Volume 150() pp:319-323
Publication Date(Web):1 April 2016
DOI:10.1016/j.talanta.2015.12.053
•A bis(8-hydroxyquinoline)-aluminium (Bhq-Al) fluorescent nanomaterial was prepared.•Bhq-Al was used to sensitively detect 2,4,6-trinitrophenol (TNP) for the first time.•Bhq-Al sensing to TNP is of exclusive even in the presence of other nitro-compounds.•A nanocomposite-based paper sensor was fabricated for the rapid detection of TNP.The reliable and accurate detection of explosives such as 2,4,6-trinitrophenol (TNP) and 2,4,6-trinitrotoluene (TNT) is in high demand for homeland security and public safety. Although extremely high sensitivity towards TNT has been demonstrated, detection of TNP remains a challenge. In this work, a fluorescent nanoscale complex composed of bis(8-hydroxyquinoline) and Al3+ ions has been prepared, characterized and applied in detection of TNP. This complex exhibits the ability to sense the nitro explosive TNP via a fluorescence quenching mechanism with high selectivity. A simple paper test system for the rapid monitoring of TNP was also investigated. The results show that Bhq-Al is a quite ideal sensing material for trace-level detection of TNP.
Co-reporter:Liang Qi, Yuan Huo, Huan Wang, Jing Zhang, Fu-Quan Dang, and Zhi-Qi Zhang
Analytical Chemistry 2015 Volume 87(Issue 21) pp:11078
Publication Date(Web):October 8, 2015
DOI:10.1021/acs.analchem.5b03166
Studying ligand–biomacromolecule interactions provides opportunities for creating new compounds that can efficiently regulate specific biological processes. Ribonucleic acid (RNA) molecules have become attractive drug targets since the discovery of their roles in modulating gene expression, while only a limited number of studies have investigated interactions between ligands and functional RNA molecules, especially those based on nanotechnology. DNA-protected silver nanoclusters (AgNCs) were used to investigate ligand–RNA interactions for the first time in this study. The anthracycline anticancer drug mitoxantrone (MTX) was found to quench the fluorescence of AgNCs. After adding human immunodeficiency virus trans-activation responsive region (TAR) RNA or Rev-response element (RRE) RNA to AgNCs-MTX mixtures, the fluorescence of the AgNCs recovered due to interactions between MTX with RNAs. The binding constants and number of binding sites of MTX to TAR and RRE RNA were determined through theoretical calculations. MTX–RNA interactions were further confirmed in fluorescence polarization and mass spectrometry experiments. The mechanism of MTX-based fluorescence quenching of the AgNCs was also explored. This study provides a new strategy for ligand–RNA binding interaction assay.
Co-reporter:Rui-Lin Liu, Xiang-Yu Gao, Lei An, Jin Ma, Ji-Fang Zhang and Zhi-Qi Zhang
RSC Advances 2015 vol. 5(Issue 114) pp:93858-93866
Publication Date(Web):19 Oct 2015
DOI:10.1039/C5RA15767F
Magnetic carbonaceous solid acids (MCSAs), which are important materials with many practical and research applications, have recently attracted much attention. In this work, a valuable type of MCSA with superparamagnetism was synthesized using a facile strategy, i.e., integrated fast pyrolysis of Fe(III)-based complexes and vapor-phase sulfonation from waste banana peel (BP). This versatile strategy enables the simple preparation of MCSAs with easily tunable surface areas (156–1097 m2 g−1) and pore volumes (0.17–0.74 cm3 g−1), and relatively large average mesoporous sizes (6.1–11.4 nm), by simply varying the dosage of Fe(III) ions. The as-prepared MCSAs have excellent catalytic activity in the esterification of oleic acid with methanol, far higher than that of the commercial Amberlyst-15, sulfonated activated carbon and niobic acid under the same conditions. In particular, the catalytic activity of the obtained MCSAs rivals that of a homogeneous H2SO4 catalyst. The present work provides an inexpensive and environmentally friendly method to synthesize MCSAs from waste BP and may contribute to a holistic approach for biomass conversion.
Co-reporter:Huan Wang, Si-Yao Liu, Xiao-Jun Lv, Rui Ma and Zhi-Qi Zhang
Analytical Methods 2015 vol. 7(Issue 12) pp:4939-4946
Publication Date(Web):06 May 2015
DOI:10.1039/C5AY00539F
Unique ternary single core–double shell structured magnetic microspheres of Fe3O4@SiO2@Fe–pamoate were successfully fabricated via a step-by-step assembly strategy. The procedures involved initial pre-treatment of silica-coated magnetic cores with carboxyl groups to functionalize the magnetic microspheres, and subsequent alternating treatments with Fe3+ and pamoic acid solutions for the growth of Fe–pamoate complexes on the microsphere surface to form Fe3O4@SiO2@Fe–pamoate magnetic microspheres. Characterization using various techniques demonstrated that the microspheres were porous, thermally stable, and possessed a single core–double shell sandwich structure. The as-synthesized materials possessed a bifunctional character derived from the magnetic properties of Fe3O4 nanoparticles and the high porosity of Fe–pamoate, making them excellent candidates as adsorbents for the magnetic enrichment of trace analytes. The potential applicability of the microspheres was demonstrated by preconcentrating sulfonamide antibiotics from environmental water samples prior to high-performance liquid chromatography analysis. The method combining enrichment with high-performance liquid chromatography had higher precision (relative standard deviations 1.4–12.3%), lower detection limits (0.08–0.12 ng mL−1), and good linearity (correlation coefficients higher than 0.9947) for five sulfonamide antibiotics investigated. Average recoveries at three spiked levels were in the range of 86.3 to 99.7% with relative standard deviations below 12.3%.
Co-reporter:Tian He, Liang Qi, Jing Zhang, Ya-Li Huang, Zhi-Qi Zhang
Sensors and Actuators B: Chemical 2015 215() pp: 24-29
Publication Date(Web):
DOI:10.1016/j.snb.2015.03.043
Co-reporter:Rui-Lin Liu, Wen-Juan Ji, Tian He, Zhi-Qi Zhang, Jing Zhang, Fu-Quan Dang
Carbon 2014 Volume 76() pp:84-95
Publication Date(Web):September 2014
DOI:10.1016/j.carbon.2014.04.052
Hierarchically porous carbon materials have many important technological applications; however, most of them were fabricated using either expensive materials or complicated procedures. Based on a general chelate-assisted multi-component co-assembly strategy, nitrogen-doped hierarchically porous carbon materials were fabricated by using Al-based composite and commercial triblock copolymer Pluronic F127 as co-templates, and natural banana peel as precursor. This versatile strategy allowed to easily achieve tunable surface area (700–2100 m2 g−1), pore volume (0.38–1.65 cm3 g−1) and a narrow average mesoporous size of ca. 2.72–4.03 nm by simply varying the dosages of Al3+ and F127, and to attain high N content (4.54 wt%) in a large-scale fabrication system (2 L). X-ray photoelectron spectroscope characterization of the as-prepared sample revealed nitrogen atoms are mainly in the form of pyridinic nitrogen, quaternary nitrogen and pyridine-N-oxide. Importantly, these as-obtained carbon materials showed excellent performance in CO2 capture and bilirubin removal with high adsorption capacities and selectivities. The present fabrication strategy is also applicable to the design of porous carbons doped with other elements by choosing appropriate biomass precursors.
Co-reporter:Xin-Yu Zhou, Jing Zhang, Rui-Ping Xu, Xue Ma, Zhi-Qi Zhang
Journal of Chromatography A 2014 Volume 1362() pp:129-134
Publication Date(Web):3 October 2014
DOI:10.1016/j.chroma.2014.08.034
•Combining phase diagrams with partition coefficient, an ABS for HSCCC was developed.•The ABS based on low-molecular-weight PEG was successfully used for HSCCC separation.•Lower viscosity of ABS is beneficial to the separation of high-viscosity substances.•The polysaccharides were first separated using HSCCC with an ABS of PEG400–Na2SO4–H2O.•Three polysaccharides were obtained from the Pericarpium granati extract using HSCCC.The aqueous biphasic system (ABS) plays a key role in the separation of bioactive substances, and the establishment and application of a low-molecular-weight polyethylene glycol (PEG) ABS remains a challenge in high-speed countercurrent chromatography (HSCCC). In this work, an ABS of low-molecular-weight PEG, namely PEG400–Na2SO4–H2O (20%–16%–64%, w/w/w), was developed on the basis of the phase diagram, and the phase forming time and ratio, and applied to HSCCC for the separation of polysaccharides. The crude polysaccharide extracted from Pericarpium granati (PGP) was successfully separated and three purified polysaccharides were obtained: PGP-1, with an average molecular weight of 13,210 Da and composed of xylose (12.4%), ribose (10.1%), and glucose (77.5%); PGP-2, which is a homogeneous polysaccharide with an average molecular weight of 2584 Da and consists of mannose; and PGP-3, with an average molecular weight of 2459 Da and composed of ribose (51.4%), mannose (26.7%), and glucose (21.9%). This success shows that an ABS based on low-molecular-weight PEG could be applied to HSCCC separation technology.
Co-reporter:Xue Ma;Xin-Yu Zhou;Qian-Qian Qiang ;Zhi-Qi Zhang
Journal of Separation Science 2014 Volume 37( Issue 14) pp:1834-1841
Publication Date(Web):
DOI:10.1002/jssc.201400070
An aqueous solution of polyethylene glycol (PEG) as a green solvent was employed for the first time to develop the ultrasound-assisted extraction of proanthocyanidins (PA) and chlorogenic acid (CA) from almond skin. The optimized extraction parameters were determined based on response surface methodology, and corresponded to an ultrasound power of 120 W, a liquid-to-solid ratio of 20:1 (mL/g), and a PEG concentration of 50% (v/v). Under these optimized conditions, the extraction yields of PAs and CA from almond skin were 32.68 ± 0.22 and 16.01 ± 0.19 mg/g, respectively. Compared with organic solvent extraction, PEG solution extraction produced higher yields. Different macroporous resins were compared for their performance in purifying PAs and CA from almond skin extract. Static adsorption/desorption experimental results demonstrated that AB-8 resin exhibits excellent purification performance at pH 4. Under the optimized dynamic adsorption/desorption conditions on the AB-8 column, the total recovery of purification for PAs and CA was 80.67%. The total content of PAs and CA in the preliminarily purified extract was 89.17% (with respective contents of 60.90 and 28.27%).
Co-reporter:Rui-Lin Liu, Fu-Yu Yin, Ji-Fang Zhang, Jing Zhang and Zhi-Qi Zhang
RSC Advances 2014 vol. 4(Issue 41) pp:21465-21470
Publication Date(Web):28 Apr 2014
DOI:10.1039/C4RA02307B
An intestine-like micro/mesoporous carbon (ILMC) was fabricated by chemically modifying banana peel and used for the size-selective separation of proteins. The as-prepared ILMC has been exemplarily characterized by FTIR, XRD, SEM, TEM and N2 adsorption measurements. The adsorption property of ILMC was further evaluated with three different molecular size proteins, cytochrome c, bovine serum albumin and lysozyme, at binary and ternary hybrid solutions. The results showed that the ILMC is effective and a highly selective adsorbent for cytochrome c. This simple and procurable ILMC may be utilized as a potential and promising support for immobilizing bio-macromolecules, drug delivery and separation.
Co-reporter:Xiao-Ni Qi;Zhao-Li Mou;Jing Zhang;Zhi-Qi Zhang
Journal of Biomedical Materials Research Part A 2014 Volume 102( Issue 2) pp:366-372
Publication Date(Web):
DOI:10.1002/jbm.a.34710
Abstract
Composite porous scaffolds have attracted extensive attention in the biomedical material field. The aim of this research was to prepare a novel tri-component composite porous scaffold and to evaluate its relevant properties. The porous scaffold was composed of chitosan (CS), silk fibroin (SF), and nanohydroxyapatite particles (nHA), which we named CS/SF/nHA scaffold and prepared via salt fractionation method combined with lyophilization. The porous structure was achieved using a porogen (salt), and the pore size was controlled by the size of porogen. To evaluate the characteristics of the tri-component scaffold, three bi-component scaffolds, CS/SF, CS/nHA, and SF/nHA, were simultaneously prepared for comparison. The scaffolds were subjected to morphological, micro-structural, and biodegradation analyses. Results demonstrated that all of the scaffolds had pore sizes of 100–300 μm and a porosity of 90.5–96.1%. The biodegradation characteristics of all scaffolds meet the requirements of good biomedical materials. The investigation of the mechanical properties showed that the tri-component scaffold has better properties than the bi-component scaffolds. The in vitro biocompatibility with osteoblast-like MG-63 cells showed that all the scaffolds are suitable for cell attachment and proliferation; however, the CS/SF/nHA composite porous scaffold is much more effective than the others. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 366–372, 2014.
Co-reporter:Zhao-Li Mou, Li-Min Duan, Xiao-Ni Qi, Zhi-Qi Zhang
Materials Letters 2013 Volume 105() pp:189-191
Publication Date(Web):15 August 2013
DOI:10.1016/j.matlet.2013.03.130
•Novel silk fibroin/collagen/hydroxyapatite scaffolds were prepared by a NaCl leaching method.•The pore structure can be controlled by altering preparation conditions.•The compositions are in uniform distribution in the scaffolds.•The scaffolds could significantly promote the proliferation of cells.A novel porous silk fibroin/collagen/hydroxyapatite (SCH) scaffold was one-step fabricated by NaCl particulate leaching method. The interconnected pore network and morphology of SCH scaffolds were determined by environmental scanning electron microscope. The scaffolds exhibited a three-dimensional (3D) porous structure with adjustable macropore size and highly interconnected porosity. The data of EDX, FTIR and XRD spectra confirmed that hydroxyapatite, silk fibroin and collagen had a homogeneous dispersion and a uniform distribution in the scaffolds. The in vitro biocompatibility with osteoblast-like MG-63 cells showed that the scaffolds could significantly promote the proliferation of cells and could be used as a biomedical material.
Co-reporter:Zhao-Li Mou, Xiao-Ni Qi, Rui-Lin Liu, Jing Zhang, Zhi-Qi Zhang
Journal of Chromatography A 2012 Volume 1243() pp:33-38
Publication Date(Web):22 June 2012
DOI:10.1016/j.chroma.2012.04.041
An efficient and convenient method, three-dimensional (3-D) cell bioreactor coupled with high performance liquid chromatography–mass spectrometry was developed for affinity screening and analysis of multiple bioactive components from herbal medicines. Cancer cells were cultured on a porous scaffold to form a 3-D cell bioreactor. After interacting with live and fixed cells, the HPLC fingerprinting chromatograms of herbal medicine extract were compared to evaluate the binding properties of herbal components on cells. Model anticancer drugs (paclitaxel and resveratrol) and non-anticancer drugs (ketoprofen and penicillin G) were chosen to investigate the feasibility. When cell–drug interaction time was 30 min, the binding degrees of paclitaxel and resveratrol (each 15 μg/ml) were 82.2 ± 7.2% and 66.1 ± 4.1%, and for ketoprofen and penicillin G (each 15 μg/ml) were less than 3%. This method was used to screen bioactive components from Polygonum cillinerve (Nakai) Ohwi (PCO) extract, and the binding degrees of two main components in PCO extract (10 μg/ml), aristolochic acid A and aristolochic acid B, were 63.0 ± 5.1% and 18.8 ± 0.9%, respectively. These results demonstrated that this method was highly specific, efficient and convenient for affinity screening and analysis of bioactive components interacted with cells.Highlights► A three-dimensional (3-D) cell bioreactor was fabricated. ► An affinity screen method was developed by coupling the bioreactor with HPLC/MS. ► The method was used to screen bioactive components in herbal medicine. ► Specific binding components with cells can be screened and analyzed.
Co-reporter:Rui-Lin Liu, Jing Zhang, Zhao-Li Mou, Shuang-Li Hao and Zhi-Qi Zhang
Analyst 2012 vol. 137(Issue 21) pp:5135-5143
Publication Date(Web):28 Aug 2012
DOI:10.1039/C2AN36178G
A rapid and practical microwave-assisted one-step extraction-derivatization (MAED) method was developed for gas chromatography-mass spectrometry analysis of fatty acids profile in herbal medicine. Several critical experimental parameters for MAED, including reaction temperature, microwave power and the amount of derivatization reagent (methanol), were optimized with response surface methodology. The results showed that the chromatographic peak areas of total fatty acids and total unsaturated fatty acids content obtained with MAED were markedly higher than those obtained by the conventional Soxhlet or microwave extraction and then derivatization method. The investigation of kinetics and thermodynamics of the derivatization reaction revealed that microwave assistance could reduce activation energy and increase the Arrhenius pre-exponential factor. The MAED method simplified the sample preparation procedure, shortened the reaction time, but improved the extraction and derivatization efficiency of lipids and reduced ingredient losses, especially for the oxidization and isomerization of unsaturated fatty acids. The simplicity, speed and practicality of this method indicates great potential for high throughput analysis of fatty acids in natural medicinal samples.
Co-reporter:Lei Liu;Rui-Lin Liu;Jing Zhang ;Zhi-Qi Zhang
Journal of Separation Science 2012 Volume 35( Issue 23) pp:3412-3420
Publication Date(Web):
DOI:10.1002/jssc.201200495
A method for PEG-based microwave-assisted extraction (MAE) of flavonoid compounds from persimmon leaves has been successfully developed. The extraction efficiency of total flavonoid content was evaluated by the chromatographic peak areas of quercetin and kaempferol, which are two bioactive components typically found in persimmon leaves. The best combination of extraction parameters was obtained with response surface methodology. A microwave power of 525 W, liquid to solid ratio of 17:1 mL/g, and PEG aqueous solution concentration of 60% w/w were identified as the optimum parameters. Extraction dynamics analysis indicated that the quercetin, kaempferol, and total flavonoid contents were rising with increasing extraction time up to 20–25 min, from which point onwards they all decreased. Under the optimum conditions, quercetin, kaempferol, and total flavonoid contents obtained from the sample were 1.20 ± 0.05, 0.64 ± 0.11, and 16.90 ± 0.06 mg/g, respectively. Compared with ethanol-based MAE, and ethanol-based and PEG-based ultrasonic-assisted extractions, PEG-based MAE had higher efficiency for the extraction of flavonoid compounds from persimmon leaves. Overall, PEG-based MAE represents an efficient choice for the extraction of bioactive substances from traditional Chinese medicines.
Co-reporter:Yu-Ling Wang, Jiang-Feng Yuan, Wei Shang, Jing Zhang and Zhi-Qi Zhang
Analyst 2011 vol. 136(Issue 4) pp:823-828
Publication Date(Web):03 Dec 2010
DOI:10.1039/C0AN00471E
An on-line dialysis sampling method coupled with high-performance liquid chromatography was developed for simultaneous investigation of the interactions between multiple bioactive compounds contained in herbal medicines and proteins. The system was used to estimate the interactions of components in danshen (Salvia miltiorrhiza) injection with bovine serum albumin. The results showed that the binding actions of five water-soluble compounds in danshen injection could be simultaneously investigated. The binding parameters of caffeic acid, ferulic acid, danshensu, protocatechuic acid and protocatechuic aldehyde were obtained and the interaction mechanisms were explored. The association constant evaluated for caffeic acid agreed well with literature values. The proposed approach should be beneficial for examining the holistic combined action of herbal medicine with proteins and help facilitate the discovery process of drug candidates.
Co-reporter:Xiao-Yan Jia, Qing-An Zhang, Zhi-Qi Zhang, Yan Wang, Jiang-Feng Yuan, Hong-Yuan Wang, Di Zhao
Food Chemistry 2011 Volume 125(Issue 2) pp:673-678
Publication Date(Web):15 March 2011
DOI:10.1016/j.foodchem.2010.09.062
This research aimed at evaluating the protective effects of almond oil against acute hepatic injury induced by carbon tetrachloride in rats. The study results showed that animals received almond oil prior to the administration of CCl4 significantly decreased serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) activities, and total cholesterol (TC), triglyceride (TG) and low density lipoprotein (LDL) content, and increased serum high density lipoprotein (HDL) content. Whereas, pre-treatment with almond oil markedly increased rat hepatic superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) levels, and decreased the malondialdehyde (MDA) level. These results combined with liver histopathology demonstrated that almond oil has potent hepatoprotective effects, and could be developed as a functional food for the therapy and prevention of liver damage.
Co-reporter:Wen-Xia Qu;Zhao-Li Mou;Hai-Yan Cui ;Zhi-Qi Zhang
Phytochemical Analysis 2011 Volume 22( Issue 3) pp:199-204
Publication Date(Web):
DOI:10.1002/pca.1265
Abstract
Introduction – Aconitum szechenyianum Gay. is a traditional Chinese medicinal herb with the detumescent and styptic effects and antitumor activity. There have been only a few researches on its chemical components, but no detailed report has appeared on its fatty acids.
Objective – To develop a simple and effective method for the extraction of fatty acids from A. zechenyianum Gay. and then to investigate the fatty acid components.
Methodology – Microwave-assisted extraction (MAE) was optimized with response surface methodology, and the fatty acid compositions of extract were determined by GC–MS with previous derivatisation to fatty acid methyl esters (FAMEs). The results were compared with that obtained by classical Soxhlet extraction (SE).
Results – Compared with SE, MAE showed significantly higher fatty acid yields, shorter extraction time, and lower energy and solvent consumption. The major fatty acids in A. szechenyianum Gay. are linoleic acid, palmitic acid, linolenic acid, oleic acid and stearic acid, and the unsaturated fatty acids occupy 66.4% of the total fatty acids. Copyright © 2010 John Wiley & Sons, Ltd.
Co-reporter:Xiao Liu, Zhi-Ping Han, Yu-Ling Wang, Yue Gao, Zhi-Qi Zhang
Journal of Chromatography B 2011 Volume 879(9–10) pp:599-604
Publication Date(Web):15 March 2011
DOI:10.1016/j.jchromb.2011.01.022
Interactions of three iridoid glycosides extracted from Cornus officinalis Sieb. et Zucc. (CIG) with protein were simultaneously explored by on-line dialysis sampling coupled with high-performance liquid chromatography (DS–HPLC). Three main compounds in CIG were unequivocally identified as loganin, sweroside and cornuside by comparing their tR, MS data and UV spectra with those of reference compounds. Dialysis recoveries and quantitative characteristics of DS–HPLC for three iridoid glycosides were determined. Recoveries of dialysis sampling ranged from 73.9 to 91.7% with the RSD below 3.0%. Based on the determination of concentrations before and after interaction with human serum albumin (HSA), the binding parameters of loganin, sweroside and cornuside with HSA were obtained and the binding mechanisms were investigated.
Co-reporter:Zhao-Li Mou, Li-Jun Zhao, Qin-An Zhang, Jing Zhang, Zhi-Qi Zhang
The Journal of Supercritical Fluids 2011 Volume 58(Issue 3) pp:398-406
Publication Date(Web):October 2011
DOI:10.1016/j.supflu.2011.07.003
Biocompatible three-dimensional scaffolds for cell culturing may facilitate methods for the repair of damaged human tissues. A novel hybrid porous scaffold of poly(lactic-co-glycolic acid), hydroxyapatite and collagen was prepared using a supercritical CO2 saturation technique. Expansion factors of scaffolds with different compositions were studied after supercritical CO2 treatment to choose the optimal composition for three-dimensional culture. The supercritical CO2 process conditions, such as saturation temperature, saturation time and saturation pressure were varied to evaluate their influence on pore structure. The results showed that the pore size and porosity of the scaffold could be controlled by manipulating these process conditions. The porous samples were characterized by environmental scanning electron microscopy, energy-dispersive X-ray spectroscope, Fourier transform infrared spectroscopy and X-ray diffractometry. Finally, MG-63 cells were successfully cultured on the porous scaffold as assessed by electron and confocal microscopy, confirming the biocompatibility of this new hybrid porous scaffold.Graphical abstractSEM micrographs of porous PLGA/HA/collagen scaffold prepared with the supercritical CO2 (a) and MG-63 cell-seeded PLGA/HA/collagen scaffold after culturing 14 days (b).Highlights► A novel porous PLGA/HA/collagen scaffold with pore sizes of 100–500 μm was successfully prepared with the supercritical CO2. ► The pore size and porosity can be regulated by supercritical CO2 saturation temperature, saturation time, and saturation pressure. ► SEM, EDX, FTIR, and XRD of the PLGA/HA/collagen scaffold demonstrated that that HA and collagen were homogeneously distributed in the scaffold. ► MG-63 cells were successfully cultured on the porous scaffold, confirming the biocompatibility of the PLGA/HA/collagen scaffold.
Co-reporter:Xuan-Feng Yue, Yan-Ni Zhang, Jin Zhang and Zhi-Qi Zhang
Analytical Methods 2010 vol. 2(Issue 6) pp:668-672
Publication Date(Web):30 Apr 2010
DOI:10.1039/B9AY00307J
Aconitum taipeicum Hand.-Mazz., widely used in traditional Chinese pharmaceuticals, has a dual effect on human health. Its alcohol extract is clinically controversial partly because its chemical components remain to be elucidated. In this paper, we report on an elaborately developed GC-MS method for the determination of free fatty acids (FFAs) in the alcohol extract of Aconitum taipeicum Hand.-Mazz., based on alcohol extraction and esterification with boron trifluoride-methanol. Six types of long chain FFAs were identified in the profile analysis, including two essential fatty acids to the human body. All the major six FFAs identified in the alcohol extract were quantified with nonadecanoic acid as an internal standard. The results showed that the alcohol extract was abundant in three types of FFAs, with unsaturated FFAs amounting to 67.42% of the total FFA content. Linoleic acid (46.24%, 13.89 ± 0.36 mg g−1) was the predominant fatty acid, followed by palmitic acid and oleic acid. These results indicate that the FFAs in the extract of Aconitum taipeicum Hand.-Mazz. contribute little to its adverse health effect.
Co-reporter:Ying-Kun Liu, Xiao-Yan Jia, Xiao Liu, Zhi-Qi Zhang
Talanta 2010 Volume 82(Issue 4) pp:1212-1217
Publication Date(Web):15 September 2010
DOI:10.1016/j.talanta.2010.06.038
Response surface methodology (RSM) was applied to the optimization of on-line solid-phase extraction (SPE) parameters, and an automated system of on-line SPE coupled with high-performance liquid chromatography (HPLC) with fluorescence detection was developed for the determination of puerarin and daidzein in human serum. The human serum sample of 50 μL was injected into a conditioned C18 SPE cartridge, and the matrix was washed out with acetonitrile–KH2PO4–triethylamine buffer (0.01 M, pH 7.4) (3:97, v/v) for 3 min at a flow rate of 0.25 mL/min. Then the target analytes were eluted and transferred to the analytical column. A chromatographic gradient elution was programmed with the mobile phase consisting of acetonitrile and KH2PO4–triethylamine buffer, and the analytes were determined with a fluorescence detector at excitation wavelength of 350 nm and emission wavelength of 472 nm, respectively. The proposed method presented good linear relations (0.85–170 μg/mL for puerarin and 0.2–40 μg/mL for daidzein), satisfactory precision (RSD < 8%), and accredited recovery (92.5–107.8%).
Co-reporter:Qing-An Zhang, Zhi-Qi Zhang, Xuan-Feng Yue, Xue-Hui Fan, Tao Li, Shou-Fen Chen
Food Chemistry 2009 Volume 116(Issue 2) pp:513-518
Publication Date(Web):15 September 2009
DOI:10.1016/j.foodchem.2009.02.071
An investigation into ultrasound-assisted extraction and autoclaving pretreatment was conducted for the oil extraction from almonds. The best possible combination of extraction parameters was obtained with the response surface methodology (RSM), at a three-variable, three-level experiment Box–Behnken design (BBD). The optimum extraction parameters were as follows: extraction time, 55 min; extraction temperature, 51 °C; and solvent/sample ratio, 19:1, at a fixed ultrasonic frequency of 40 kHz and power of 150 W. Under these conditions, the oil recovery was 81.89 ± 0.23% for the autoclaved almonds, which well matches with the predicted value. Furthermore, the oil composition was analyzed with GC–MS, and the effect of the autoclaving on the oil extraction was evaluated. The results showed that the autoclaving pretreatment increased the oil recovery, without affecting the oil composition, by 8.69%, which confirmed the efficacy of the autoclaving on the oil extraction from almond powder.
Co-reporter:Xiao-Qing Zhao, Zhi-Qi Zhang
Talanta 2009 Volume 80(Issue 1) pp:242-245
Publication Date(Web):15 November 2009
DOI:10.1016/j.talanta.2009.06.066
A rapid and sensitive flow injection fluorometry has been developed for the determination of formaldehyde based on the microwave on-line accelerating its Hantzsch reaction with cyclohexane-1,3-dione. Under the optimized conditions, the fluorescent intensity is proportional to formaldehyde content in the range from 0.05 ng/mL to 2.000 μg/mL. The detection limit (S/N = 3) is 0.02 ng/mL and the analytical frequency is 28 injections per hour. The relative standard deviations are 2.2% and 3.1% for eleven injections of 0.100 and 0.001 μg/mL of formaldehyde, respectively. With the assistance of microwave irradiation, a best sensitive fluorometry was established for the determination of formaldehyde at a high analytical frequency. This method was successfully applied to food analysis without requiring any sample pretreatment, and the determination results were correlated well with those obtained by the standard method with a sample pretreatment of steam distillation.
Co-reporter:Zhi-Chao Fan;Zhi-Qi Zhang
Journal of Chemical Crystallography 2008 Volume 38( Issue 12) pp:895-899
Publication Date(Web):2008 December
DOI:10.1007/s10870-008-9399-6
3-Acetylaconitine (1), C36H49NO12, was isolated from the ammonium hydroxide wetted root of A. szechenyianum Gay. X-ray diffraction analysis demonstrated that it consists of four-six-membered rings A, B, C, D and two-five-membered rings E, F. The fused-ring system A, B, C and D are in chair, chair, chair and boat conformations, respectively; ring E is in a half-chair; and ring F is in an envelope confirmation. The crystal of 3-acetylaconitine is in orthorhombic crystal system with space group P212121, lattice constants: a = 9.2002(8) Å, b = 11.06454(9) Å, and c = 33.072(3) Å, V = 3543.3(5) Å3, Z = 4.
Co-reporter:Zhi-Chao Fan;Zhi-Qi Zhang
Structural Chemistry 2008 Volume 19( Issue 3) pp:413-419
Publication Date(Web):2008 June
DOI:10.1007/s11224-008-9296-9
Two napelline skeletal diterpenoid alkaloids 15-acetylsongorine, C24H33NO4 I, and songoramine, C22H29NO3 II, were first isolated from the roots of Aconitum Szechenyianum Gay. The crystal structures were determined by X-ray single-crystal diffraction analysis. The crystal I is the triclinic system with space group P1 having unit cell parameters of a = 9.360(8) Å, b = 11.593(9) Å, c = 11.830(16) Å, α = 113.223(15)°, β = 105.950(16)°, γ = 101.296(12)°, and Z = 2. Hydrogen bonds O–H···O and O–H···N joint the molecules into dimer. The crystal II belongs to the orthorhombic system with space group P212121 having unit cell parameters of a = 8.950(2) Å, b = 13.272(3) Å, c = 15.454(4) Å and Z = 4. The O–H···O hydrogen bonding interaction links the molecule into linear chains. The distortion of rings of compound I and II were evaluated by calculation of the Cremer and Pople puckering parameters. The presence of the C–O–C bond in the compound II results in the changes of ring conformations compared with that of the compound I.
Co-reporter:Zhi-Chao Fan;Zhi-Qi Zhang
Journal of Chemical Crystallography 2008 Volume 38( Issue 8) pp:635-639
Publication Date(Web):2008 August
DOI:10.1007/s10870-008-9361-7
Songorine was isolated from the root of Aconitum szechenyianum Gay and its crystal structure was determined by X-ray single crystal diffraction. The compound compactly packs in an orthorhombic unit cell in the P212121 space group with unit cell dimensions a = 9.7733(7) Å, b = 13.4892(9) Å, c = 14.8097(10) Å, V = 1952.4(2) Å3 and Z = 4. A series of intricate hydrogen bonds assemble the title compound into a three-dimensional networking structure.
Co-reporter:Xuan-Feng Yue, Yan-ni Zhang, Zhi-Qi Zhang
Food Chemistry 2007 Volume 102(Issue 1) pp:90-94
Publication Date(Web):2007
DOI:10.1016/j.foodchem.2006.05.005
An air-driving flow injection device with merging zones technique is proposed for the rapid determination of formaldehyde in pale beers based on its catalytic action on the redox reaction between Victoria Blue B and potassium bromate in phosphoric acid medium. The reaction is monitored spectrophotometrically by measuring the decrease in absorbance of Victoria Blue B at the maximum absorption wavelength of 618 nm. Only 160 μL reagents and 40 μL sample solutions are needed. Formaldehyde in the range 8–700 ng mL−1 can be determined at a rate of about 50 samples h−1, the RSD for the determination of 20 ng m L−1 formaldehyde is 2.1%. Due to appropriate consideration of the beer matrix, formaldehyde in beers can be determined directly and satisfactory results were obtained.
Co-reporter:Zhi-Qi Zhang, Jian Ma, Ying Lei, Yue-Mei Lu
Talanta 2007 Volume 71(Issue 5) pp:2056-2061
Publication Date(Web):30 March 2007
DOI:10.1016/j.talanta.2006.09.016
A simple, sensitive and specific fluorimetric method has been developed for the determination of thioridazine hydrochloride in human plasma involving solid phase extraction (SPE). In a flow-injection system, thioridazine hydrochloride is on-line oxidized into a strongly fluorescent compound with a lead dioxide solid-phase reactor and the fluorescence intensity is measured with a fluorescence detector (λex = 349 nm, λem = 429 nm). A comparison of plasma sample pretreatment between SPE procedure and precipitation method was made and the results showed that SPE procedure was better than precipitation method. Under the optimum conditions, the fluorescence intensity is proportional to the concentration of thioridazine hydrochloride in the range from 0.015 to 2.000 μg mL−1. The detection limit is 5.5 ng mL−1 of thioridazine hydrochloride and the relative standard deviation is 1.06%. This method has been applied to determination of thioridazine hydrochloride in real patients plasma samples with the results compared with those obtained by HPLC method.
Co-reporter:Zhi-Qi Zhang, Guo-Xi Liang
Analytica Chimica Acta 2005 Volume 536(1–2) pp:145-151
Publication Date(Web):22 April 2005
DOI:10.1016/j.aca.2004.12.065
The mechanism of binding of carbamazepine (CBZ) with bovine serum albumin (BSA) has been investigated in vitro based on a new flow injection fluorometry coupled to the technique of dialysis sampling. The CBZ and BSA were mixed in different molar ratios in 0.050 mol L−1 phosphate buffer (containing 0.9% NaCl), pH 7.4, and incubated at 37 ± 0.5 °C in a water bath. The dialysis sampler was utilized to sample free CBZ from mixed solution with a relative dialytic efficiency of 7.6%. Then the CBZ in dialysis solution was injected into carrier and on-line oxidized by lead dioxide solid-phase reactor into fluorescent product with a maximum excitation wavelength of 355 nm and a maximum emission wavelength of 478 nm. The fluorescence intensity measured was linear proportional with the concentration of free CBZ in mixed solution over the range of 1 × 10−5 to 2 × 10−4 mol L−1 with the detection limit of 6 × 10−6 mol L−1. According to the fluorescence measurement results from mixed solution, the association constant (K) estimated for CBZ–BSA binding and the number of the binding site (n) with Scatchard analysis were 1.08 × 104 L mol−1 and 0.94, respectively. Stern–Volmer plots indicated the presence of dynamic component in the quenching mechanism. The acting force was suggested to be mainly hydrophobic and the distance between the acceptor and donor was 3.12 nm. The estimated binding parameters agreed well with literature values.
Co-reporter:Xuan-Feng Yue, Zhi-Qi Zhang, Hong-Tao Yan
Talanta 2004 Volume 62(Issue 1) pp:97-101
Publication Date(Web):9 January 2004
DOI:10.1016/S0039-9140(03)00421-1
A new flow injection catalytic spectrophotometric method is proposed for the simultaneous determination of nitrite and nitrate based on the catalytic effect of nitrite on the redox reaction between crystal violet and potassium bromate in phosphoric acid medium and nitrate being on-line reduced to nitrite with a cadmium-coated zinc reduction column. The redox reaction is monitored spectrophotometrically by measuring the decrease in the absorbance of crystal violet at the maximum absorption wavelength of 610 nm. A technique of inserting a reduction column into sampling loop is adopted and the flow injection system produces a signal with a shoulder. The height of shoulder in the ascending part of the peak corresponds to the nitrite concentration and the maximum of the peak corresponds to nitrate plus nitrite. The detection limits are 0.3 ng ml−1 for nitrite and 1.0 ng ml−1 for the nitrate. Up to 32 samples can be analyzed per hour with a relative standard deviation of less than 2%. The method has been successfully applied for the simultaneous determination of nitrite and nitrate in natural waters.
Co-reporter:Si-Si Liang, Liang Qi, Rui-Ling Zhang, Meng Jin, Zhi-Qi Zhang
Sensors and Actuators B: Chemical (June 2017) Volume 244() pp:585-590
Publication Date(Web):June 2017
DOI:10.1016/j.snb.2017.01.032
Co-reporter:Ying-Kun Liu, E. Yan, Han-Ying Zhan, Zhi-Qi Zhang
Journal of Pharmaceutical Analysis (February 2011) Volume 1(Issue 1) pp:13-19
Publication Date(Web):1 February 2011
DOI:10.1016/S2095-1779(11)70003-X
Microwave-assisted extraction was optimized with response surface methodology for HPLC-fluorescence determination of puerarin and daidzein in Radix Puerariae thomsonii. The optimized extraction procedure was achieved by soaking the sample with 70% methanol (1:15, v/v) for 30 min, and then microwave irradiation for 11 min at a power of 600 W. Coupling the extraction process with HPLC-fluorescence presented good recovery, satisfactory precision, and good linear relation. Compared with a method from the Chinese Pharmacopoeia, the proposed method enables higher extraction efficiency and more aecurate analytical results. It can be of Potential value in quality assessment of Radix Puerariae thomsonii medicinal materials.
Co-reporter:Meng Jin, Zhao-Li Mou, Rui-Ling Zhang, Si-Si Liang, Zhi-Qi Zhang
Biosensors and Bioelectronics (15 May 2017) Volume 91() pp:
Publication Date(Web):15 May 2017
DOI:10.1016/j.bios.2016.12.022
•A ratiometric fluorescence sensor for 6-mercaptopurine (6-MP) was developed.•The sensor was constructed by combining MOF with CdTe quantum dots.•Superior selectivity and comparable sensitivity were achieved.•The sensor was successfully applied to determine 6-MP in urine sample.The development of a simple and accurate quantitative method for the determination of 6-mercaptopurine (6-MP) is of great importance because of its serious side effects. Ratiometric fluorescence (RF) sensors are not subject to interference from environmental factors, and exhibit enhanced precision and accuracy. Therefore, a novel RF sensor for the selective detection of 6-MP was developed based on a dual-emission nanosensor. The nanosensor was fabricated by combining a blue-emission metal-organic framework (MOF) NH2-MIL-53(Al) (λem=425 nm) with green-emission 3-mercaptopropionic acid-capped CdTe quantum dots (MPA-CdTe QDs) (λem=528 nm) under a single excitation wavelength (335 nm). Upon addition of 6-MP, the fluorescence of NH2-MIL-53(Al) in the nanohybrid was selectively quenched due to strong inner filter effects, while the fluorescence of the MPA-CdTe QDs was enhanced. The novel RF sensor exhibited higher selectivity towards 6-MP than CdTe QDs alone, and higher sensitivity than MOFs alone. 6-MP could be detected in the range of 0–50 μM with a detection limit of 0.15 μM (S/N=3). The developed sensor was applied for the determination of 6-MP in human urine samples and satisfactory results were obtained. Overall, a novel and efficient fluorescence-based method was developed for the detection of 6-MP in biosamples.Schematic illustration of the developed ratiometric fluorescent sensor for 6-MP.
Co-reporter:Xuan-Feng Yue, Yan-Ni Zhang, Jin Zhang and Zhi-Qi Zhang
Analytical Methods (2009-Present) 2010 - vol. 2(Issue 6) pp:NaN672-672
Publication Date(Web):2010/04/30
DOI:10.1039/B9AY00307J
Aconitum taipeicum Hand.-Mazz., widely used in traditional Chinese pharmaceuticals, has a dual effect on human health. Its alcohol extract is clinically controversial partly because its chemical components remain to be elucidated. In this paper, we report on an elaborately developed GC-MS method for the determination of free fatty acids (FFAs) in the alcohol extract of Aconitum taipeicum Hand.-Mazz., based on alcohol extraction and esterification with boron trifluoride-methanol. Six types of long chain FFAs were identified in the profile analysis, including two essential fatty acids to the human body. All the major six FFAs identified in the alcohol extract were quantified with nonadecanoic acid as an internal standard. The results showed that the alcohol extract was abundant in three types of FFAs, with unsaturated FFAs amounting to 67.42% of the total FFA content. Linoleic acid (46.24%, 13.89 ± 0.36 mg g−1) was the predominant fatty acid, followed by palmitic acid and oleic acid. These results indicate that the FFAs in the extract of Aconitum taipeicum Hand.-Mazz. contribute little to its adverse health effect.
Co-reporter:
Analytical Methods (2009-Present) 2015 - vol. 7(Issue 12) pp:NaN4946-4946
Publication Date(Web):2015/05/06
DOI:10.1039/C5AY00539F
Unique ternary single core–double shell structured magnetic microspheres of Fe3O4@SiO2@Fe–pamoate were successfully fabricated via a step-by-step assembly strategy. The procedures involved initial pre-treatment of silica-coated magnetic cores with carboxyl groups to functionalize the magnetic microspheres, and subsequent alternating treatments with Fe3+ and pamoic acid solutions for the growth of Fe–pamoate complexes on the microsphere surface to form Fe3O4@SiO2@Fe–pamoate magnetic microspheres. Characterization using various techniques demonstrated that the microspheres were porous, thermally stable, and possessed a single core–double shell sandwich structure. The as-synthesized materials possessed a bifunctional character derived from the magnetic properties of Fe3O4 nanoparticles and the high porosity of Fe–pamoate, making them excellent candidates as adsorbents for the magnetic enrichment of trace analytes. The potential applicability of the microspheres was demonstrated by preconcentrating sulfonamide antibiotics from environmental water samples prior to high-performance liquid chromatography analysis. The method combining enrichment with high-performance liquid chromatography had higher precision (relative standard deviations 1.4–12.3%), lower detection limits (0.08–0.12 ng mL−1), and good linearity (correlation coefficients higher than 0.9947) for five sulfonamide antibiotics investigated. Average recoveries at three spiked levels were in the range of 86.3 to 99.7% with relative standard deviations below 12.3%.
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