As one of the most important posttranslational modifications, protein phosphorylation plays an important role in vital movement. However, an efficiency enrichment treatment prior to MS detection is still a crucial step to protein phosphorylation analysis. In this work, a novel hybrid microsphere for efficient phosphopeptide enrichment was prepared by reverse-phase suspension polymerization of cellulose derivative and chitosan. The microspheres bore different kinds of amine groups and the main enrichment mechanism was based on anion exchange. This approach exhibited high selectivity for phosphopeptides from β-casein, α-casein, and non-fat milk. Three phosphopeptides could still be detected when the amount of β-casein was as low as 10 fmol. This study demonstrated a new attractive solid-phase support for phosphopeptide enrichment to meet the increasing need of phosphoproteomics analysis.

A unique boronate-functionalized SiO2/TiO2 hybrid monolithic column was synthesized by a facile approach. Although a conventional boronic acid, 4-vinylphenylboronic acid, was used as the affinity ligand, the prepared monolithic column exhibited specific capacity to capture glycoproteins including antibodies in aqueous solution at neutral pH. With the incorporation of titania, the monolith was highly hydrophilic, and the procedure of affinity chromatography could be performed under aqueous organic-solvent-free conditions.

•Octadecyl modified quaternized cellulose (ODMQC) was successfully synthesized.•ODMQC could self-assemble to form stable nanoparticles in aqueous solution.•ODMQC coating could generate anodal eletroosmotic flow over a broad pH range.•ODMQC did not only favor the separation of charged solutes but also neutral solutes.In this work, a new cellulose derivative, octadecyl modified quaternized cellulose (ODMQC), was synthesized and used as additive in the background electrolyte for capillary electrophoresis. The derivative bearing hydrophobic groups and hydrophilic groups can self-assemble into a stable nano-scaled micelle structure in aqueous solution. When ODMQC was added in running buffer, the capillaries were shown to generate applicable anodal EOF over the investigated range of pH 3.0–12.0. Due to the lack of UV active groups, the ODMQC did not disturb the UV detection. It is shown that ODMQC-added capillaries allow the separation of basic proteins by reducing their adsorption onto the capillary wall. Also, the addition of ODMQC provides adequate separation of aromatic acids with low pKa values and improved separation of sulfa drugs. Moreover, it is demonstrated that the addition of ODMQC can incorporate an additional reversed-phase mechanism that improves the separation of neutral analytes.

A new hybrid organic–inorganic monolithic column for efficient deoxyribonucleic acid (DNA) extraction was prepared in situ by polymerization of N-(β-aminoethyl)-γ-aminopropyltriethoxysilane (AEAPTES) and tetraethoxysilane (TEOS). The main extraction mechanism was based on the Coulombic force between DNA and the amino silica hybrid monolithic column. DNA extraction conditions, such as pH, ion concentration and type, and loading capacity, were optimized online by capillary electrophoresis with laser-induced fluorescence detection. Under optimal condition, a 6.0-cm monolithic column provided a capacity of 48 ng DNA with an extraction efficiency of 74 ± 6.3% (X ± RSD). The DNA extraction process on this monolithic column was carried out in a totally aqueous system for the successful purification of DNA and removal of proteins. The PBE2 plasmid could be extracted from Bacillus subtilis (B. subtilis) crude lysate within 25 min, and the purified DNA was suitable for the amplification of a target fragment by polymerase chain reaction. This study demonstrates a new attractive solid-phase support for DNA extraction to meet the increasingly miniaturized and automated trends of genetic analyses.

A hydroxyapatite (Hap) monolithic column with micrometer macropores skeleton structure was prepared by sol–gel technique for efficient DNA extraction. The main extraction mechanism of this monolithic column was attributed to the electrostatic interaction between the phosphate groups of DNA and the calcium ions (C site) of Hap. DNA extraction conditions, such as pH, ion concentration, ion type and loading capacity, on the monolithic column were optimized online by capillary electrophoresis with laser-induced fluorescence detection. Under the optimal condition, a 6 cm length monolithic column provided a capacity of 40 ng DNA with an extraction efficiency of 64 ± 6.2% (X ± RSD). As low concentration of salts were used in the extraction procedure, the purified PBE2 plasmid from the Bacillus subtilis crude lysate could be amplified by polymerase chain reaction. This result illustrated that Hap was a potential matrix for DNA purification from complex biological samples which was compatible with the subsequent genetic analysis in miniature format. Since the preparation of this monolithic column was very simple, it was possible to integrate this novel matrix with chip to allow rapid and efficient DNA purification in microscale. This study provided a new attractive solid-phase support for DNA extraction to meet the miniaturized and automated trends of genetic analysis.

An enzyme immunoassay based on the use of crossed-beam thermal lens detection is described. In this assay, poly-N-isopropylacrylamide, a water-soluble, thermally precipitating synthetic polymer, was used as a carrier to minimize non-specific binding. The enzyme substrate of the horseradish peroxidase that was employed was 3,3′,5,5′-tetramethylbenzidine. The color development of the enzyme–substrate reaction was stopped by SDS and Na2SO3 to achieve a stable blue solution. The background reduction and stabilization made it possible to use a crossed-beam thermal lens technique as the measurement method. This method was demonstrated to be applicable by determination of hepatitis B surface antigen in human serum. A detection limit of 0.15 ng/ml was obtained. This was more sensitive than that of the commercially available ELISA method.