•A bis-imidazolium functionalized tetraphenylethene probe was prepared.•This probe self-assemble finite small sphere nanoaggregates in aqueous solution.•The probe can recognize pyrophosphate anion with strong aggregation-induced emission.•The probe/pyrophosphate assembly can fluorescence assay alkaline phosphatase.A novel tetraphenylethene-based probe bearing bis-imidazolium anion donors is herein reported for pyrophosphate anion recognition. This probe can self-assemble finite, small sphere nanoaggregates with very weak emission in aqueous solution, and changes into large rod-like nanoaggregates with strong aggregation-induced emission upon binding with the pyrophosphate anion.A novel nanoaggregates for recognition of pyrophosphate anion with aggregation-induced emission in pure aqueous solution is introduced.Download high-res image (128KB)Download full-size image

•A pyrenyl-appended organogel was prepared.•It shows gel-gel phase and the emission quenching changes toward F−.•It shows a gel-sol transition toward AcO−.A 1,2,3-trioctyloxyphenyl-based organogel (G1) containing a pyrene fluorophore and urea-sulfonamide anion binding sites was designed and synthesized. Gelator G1 can form stable organogels with dramatic aggregation-induced emission (AIE) in some organic solvents. The self-assemble mechanism of G1 was investigated by concentration depended 1H NMR, XRD, FT-IR and SEM techniques. In addition, G1 shows good fluorescence sensing ability to some selected anions such as F− and AcO−. In DMF solution, the addition of F− into the organogel G1 shows a gel-gel phase change with the AIE quenched. However, the addition of AcO− leads to a gel-sol transition with little fluorescence change.Download high-res image (213KB)Download full-size image

Fluorescent organic nanoparticles (FONs) based on an aggregation-induced emission (AIE) dye have recently received increasing interest owing to their unique optical properties, water dispersibility and biocompatibility. However, fabrication of multifunctional AIE-active FONs through a facile controlled free radical polymerization method has not been reported thus far. In this work, a novel photo-initiated reversible addition–fragmentation chain-transfer (RAFT) polymerization has been developed for the fabrication of AIE-active FONs for the first time. During this procedure, a new tetraphenylethene based dye (named TPE-DETC) was conjugated to a chain transfer agent, which could serve as the fluorescence signal and catalyst for RAFT polymerization. Styrene (SE) and itaconic acid (IA) were selected as the monomers to construct the final fluorescent copolymers (TPE-SE-IA). Due to the amphiphilicity and AIE properties of TPE-DETC, the TPE-SE-IA copolymers tend to self-assemble and form FONs. The physicochemical properties, drug loading and release behavior of TPE-SE-IA FONs towards cisplatin (CDDP), their biocompatibility as well as cell uptake behavior have been investigated in detail. The results verified that TPE-SE-IA FONs possess strong fluorescence, high water dispersibility, distinguished biocompatibility and highly efficient drug loading capability, making them promising candidates for biomedical applications. More importantly, the in situ photo-initiated RAFT polymerization strategy is an ideal method to be used for the preparation of functional polymeric materials owing to its fascinating features, such as environmental friendliness, mild reaction conditions, being catalyst-free and cost effectiveness.

A novel amphiphilic imidazolium-based probe containing a dansyl fluorophore and a long cetyl chain has been developed for ATP recognition. The probe forms self-assembled micelle-like aggregates at low concentration in its aqueous solution and can selectively recognize ATP among other bioactive anions with a significant enhancement in fluorescence emission.

A new pyrene-appended triazolium has been synthesized and explored as a highly efficient receptor for fluoride anions. In an CH3CN–H2O competitive solution, this probe shows an exclusive fluorescence turn-off sensing of F− over other anions. 1H NMR titrations and density functional theory (DFT) calculations revealed that the triazolium (CH)+, sulfonamide NH and pyrenyl CH donors were involved in hydrogen bonding interactions with a F− anion to form a stable 1–F− complex. In addition, the probe was successfully applied to the detection of F− from inorganic origins in the solid state.

•Aggregation-induced emission luminescent polymeric nanoparticles•A one-pot multicomponent reaction•AIE-active LPNs containing dynamic linkages•The AIE-active LPNs are promising for biomedical applications.Luminescent polymeric nanoparticles (LPNs) with aggregation-induced emission (AIE) feature have emerged as the most promising candidates for biological imaging owing to their unique AIE feature, great water dispersity, strong fluorescence, low cytotoxicity and biocompatibility. Although numerous successful strategies for construction of AIE-active LPNs have been developed, the preparation of dynamic linkages containing AIE-active LPNs based on multicomponent reactions has been rarely reported. In this work, we report a facile method for the formation of AIE-active LPNs via a one-pot conjugation of PEG-B(OH)2, 1-thioglycerol and AIE-active dye PhE-alc in short time under rather mild reaction conditions (e.g. ambient temperature, air atmosphere, absent of metal catalysts and in the present of water). The successful formation of AIE-active mPEG-PhE LPNs was confirmed by different characterization techniques in details. The great optical and biological properties certified their applicable for biological imaging application. More importantly, the novel method for the formation of AIE-active LPNs is rather simple, high efficiency and atom economy, which greatly enriched their practical biomedical applications.A facile one-pot strategy based on the formation of dynamic bonds has been developed for the fabrication of luminescent polymeric nanoparticles with aggregation-induced emission feature.Download high-res image (166KB)Download full-size image

•New tripodal triazole-based receptor was synthesized by click reaction.•This receptor show distinctive fluorescence sensing of Ni2+.•The detection limit for Ni2+ is low.A new click-derived tripodal receptor, tris[(9-anthryl benzyl-1H-1,2,3-triazole-4-yl)methyl]amine (1), was synthesized from tripropargylamine and anthracene azide by Cu(I)-catalyzed click chemistry. In acetonitrile/Tris-HCl (1:1, v/v, pH = 7.2) buffer solutions, 1 showed exclusive fluorescence turn-off response to Ni2+ over other metal ions. The detection limit for Ni2+ is 7.1 × 10−7 M.A new tripodal triazole-based receptor for fluorescence sensing of Ni2+ in aqueous solution is reported.

•Cyclic and acyclic ferrocene-containing triazoles were synthesized.•All receptors show distinctive electrochemical sensing of H2PO4−.•The binding mechanism was investigated by 1H NMR spectrum and DFT calculation.Two novel ferrocene-containing macrocyclic triazoles (L1 and L2) and their acyclic analogs (L3 and L4) were easily prepared by “click” reaction. The anions binding abilities of L1–L4 were evaluated by cyclic voltammetry and differential pulse voltammetry methods. The results revealed that the receptors L1–L4 have exclusive electrochemical sensing of H2PO4−, with the shift in redox potentials of L1–L4 towards the cathodic values. The binding mechanisms between the receptors and H2PO4− were examined by 1H NMR titrations and density functional theory (DFT) calculations.Two new ferrocene-containing macrocyclic triazoles and their acyclic compared compounds for electrochemical sensing of H2PO4− are reported.

•A new anthracenyl-appended ferrocene bearing the aniline N and thiourea S donors for metal ions recognition was prepared.•The sensor shows fluorescent and electrochemical sensing of Cu2+ and Hg2+ in CH3CN solution.•It only shows fluorescence turn-on response to Hg2+ in CH3CN–Tris (1:1, v/v) buffer solution.•1H NMR analysis and DFT calculations revealed the binding mode.A new anthracenyl-appended ferrocene bearing the aniline N and the thiourea S donors (1) for multiple signaling sensing of metal ions, has been synthesized and characterized. Upon addition of various metal ions in CH3CN solution, 1 shows a distinctive response to Cu2+ and Hg2+ over other metal ions, with a large enhancement of the emission of 1, and an anodic shift of electrochemical potential. In contrast, in CH3CN–Tris (1:1, v/v) buffer solution, 1 only shows a fluorescence turn-on response to Hg2+ over other metal ions, which can distinguish Hg2+ from Cu2+ and other metal ions. Furthermore, the supposed binding mode of 1 with Hg2+ and/or Cu2+ was also discussed according to the 1H NMR titration and the theoretical calculation results by density functional theory (DFT) method.

A hydroxyquinoline functionlized polynorbornene (P1) was designed and synthesized. In an aqueous solution, P1 shows a “turn-on” fluorescence response for Zn2+ and Cd2+ with a 50 nm blue shift. Furthermore, both P1-Zn2+ and P1-Cd2+ complexes were found to respond to pyrophosphate (PPi) over other important biological anions via a fluorescence quenching effect. P1 is also capable of monitoring intracellular Zn2+ and PPi in real time.

New mono- and di-substituted pyrene-appended ferrocenes bearing amide or amide–sulfonamide binding sites, 1–4, have been synthesized, and their anion recognition abilities have been investigated. In CH3CN solution, all receptors show distinctive electrochemical sensing of F− and H2PO4− with a large cathodic shift in the ferrocene/ferrocenium redox potential, with 4 showing the strongest anion binding ability. In addition, receptors 3 and 4 bearing amide–sulfonamide binding sites also exhibit fluorescence response to AcO− and H2PO4− with a large enhancement in their emission intensity. The binding mechanisms between 3 and anions are also investigated by 1H NMR titration and DFT calculations.

•A new dinuclear ferrocene-base receptor was synthesized.•It shows distinctive electrochemical sensing to Hg(II).•It shows electrochemical sensing to H2PO4− over other anions.•The binding mechanism was investigated by ESI-MS and 1H NMR spectrum.A new dinuclear ferrocene-base receptor bearing amide and thiourea binding sites, 1, was prepared and characterized by X-ray crystal structure analysis. This receptor shows a dual electrochemical sensing to Hg(II) and anions. Upon the addition of Hg(II), its redox potential shows a positive shift for the mercury-promoted intramolecular cyclic guanylation mechanism. In addition, 1 also shows distinctive electrochemical sensing to H2PO4− over other anions with a large negative shift of its redox potential for N–H…anion hydrogen bond interaction between anion and 1.A new dinuclear ferrocene-base receptor bearing amide and thiourea binding sites, 1, was synthesized. 1 shows distinctive electrochemical sensing to Hg(II) with a positive shift its redox potential. 1 also shows electrochemical sensing to H2PO4− over other anions with a large negative shift its redox potential.

•Cyclic and acyclic naphthalene-containing triazoles were synthesized.•Both receptors show distinctive fluorescent sensing to Hg(II).•Cyclic receptor shows better sensitivity and selectivity than acyclic compound.•The binding mechanism was investigated by 1H NMR spectrum and DFT calculation.A new naphthalene-containing macrocyclic triazole (1) and its acyclic compared compound (2) have been synthesized and characterized. In acetonitrile and acetonitrile aqueous solutions, 1 and 2 showed good fluorescence sensing ability to Hg2+ over other metal ions, with 1 exhibiting better sensitivity and selectivity than 2 owing to its macrocyclic effect. 1H NMR titrations and DFT calculation results showed that the N atoms of triazole and O atoms of the ether groups in 1 and 2 participate in binding during complexation with Hg2+.Graphical abstractA new naphthalene-containing macrocyclic triazole and its acyclic compared compound for fluorescence recognition of Hg2+ are reported.

•A new pyrenyl-appended triazole-based fluorescent sensor for Hg2+ was prepared.•This chemosensor shows distinctive fluorescent quenching selectivity toward Hg2+ in the acetonitrile aqueous solution.•1H NMR analysis and DFT calculations revealed the binding mechanism.A new pyrenyl-appended triazole for fluorescent sensing of Hg2+, 1, has been synthesized and characterized. Upon addition of Hg2+ to 1 in the acetonitrile aqueous solution, more than 80% of the initial fluorescence intensity of 1 was quenched, which allowed a selective and sensitive fluorescent detection of Hg(II) without any interference from other metal ions. 1H NMR analysis revealed that the two sulfonamide and triazole groups of 1 played a critical role in the interactions with Hg2+ ion, which can be further proved by the density functional theory based theoretical calculation.

A novel anthracene-based anion receptor 1 bearing two 1,2,3-triazolium donor groups has been designed and synthesized. In competitive solvents, compound 1 shows effective selectivity toward H2PO4- in a fluorescence enhancement effect, with no interference from other anions.Figure optionsDownload full-size imageDownload as PowerPoint slide

A new series of 2,6-diphenylpyridine-based fluorophores with different type of substituents (R = Br, H, OMe, NMe2 and NPh2 for 2–6) were prepared, and their photophysical properties in neutral and protonated state were investigated. With the increasing of the donor ability of substituents in 2–6, their UV/vis and emission spectra show a successive red shift. In addition, a large intramolecular charge transfer (ICT) was observed in 5 and 6, which can be confirmed by time-dependent density functional theory (TD-DFT) calculation, and X-ray crystallographic analysis for 5. All compounds studied in this work show proton-sensitive fluorescence. It was found that 2 and 3 were capable of ratiometric emission signaling of protons, 4 and 6 showed proton-induced quenching in their fluorescence, while 5 revealed a proton-induced ON–OFF–ON switching of its emission.Highlights► A series of 2,6-diphenylpyridine-based fluorophores were prepared. ► Solvent dependent UV/vis and emission spectra was observed. ► TD-DFT calculation and X-ray crystallographic analysis confirmed intramolecular charge transfer. ► All compounds studied in this work show proton-sensitive fluorescence.

Three new copper(I) complexes with tricyclohexylphosphine (PCy3) and different diimine ligands, [Cu(phen)(PCy3)]BF4 (1) (phen = 1,10′-phennanthroline), [Cu(bpy)(PCy3)2]BF4 (2) (bpy = 2,2′-bipyridine) and [Cu(MeO-CNN)(PCy3)]BF4 (3) (MeO-CNN = 6-(4-methoxyl)phenyl-2,2′-bipyridine), have been synthesized and characterized. X-ray structure reveals that complexes 1 and 3 are three-coordinated with trigonal geometry, while complex 2 adopts distorted tetrahedron geometry. Complexes 1 and 3 exhibit ligand redistribution reactions in chloromethane solution by addition of excess amount of PCy3, in which three-coordinated 1 changes into four-coordinated [Cu(phen)(PCy3)2]+, and 3 leads to form [Cu(PCy3)2]BF4 and CNN-OMe. All the three complexes display yellow 3MLCT emissions in solid state at room temperature with λmax at 558, 564 and 582 nm for 1, 2 and 3, respectively, and red-shift to 605, 628 and 643 nm at 77 K in dichloromethane solution.Three novel copper(I) complexes with tricyclohexylphosphine and different diimine ligands have been synthesized and characterized. X-ray structure shows that the center atom adopts three or four-coordinated geometry according to the diimine ligand. Their UV–Vis spectrum, emission spectrum and ligand redistribution reactions in chloromethane solution are also discussed.

A novel organo-functionalized mesoporous MCM-41 type of hybrid materials MCM–Si–DPBB was synthesized by co-condensation of bidentate Si(OR)3 substituted N,N-2-diphenyloxyphosphine-4-bromomethyl-benzenamine (Si–DPBB) and tetraethoxysilane (TEOS) in the presence of the cetyltrimethylammonium bromide (CTAB) surfactant as template. Its ternary europium complex covalently bonded to the silica-based network MCM–Si–DPBB–Eu was also prepared by introduction the Eu(DBM)3(H2O)2 into the hybrid materials. The hybrid material MCM–Si–DPBB–Eu has strong luminescence, and when excited by the ligands absorption wavelength (386 nm), it displays the emission of the Eu3+5D0-7FJ (J = 0, 1, 2, 3 and 4) transition lines due to the efficient energy transfer from the ligands to Eu3+.A novel organo-functionalized mesoporous MCM-41 type of hybrid materials MCM–Si–DPBB and its ternary europium complex covalently bonded to the silica-based network MCM–Si–DPBB–Eu were synthesized and characterized. The hybrid material MCM–Si–DPBB–Eu has strong luminescence, and displays the emission of the Eu3+5D0-7FJ (J = 0, 1, 2, 3 and 4) transition lines due to the efficient energy transfer from the ligands to Eu3+.

A hydroxyquinoline functionlized polynorbornene (P1) was designed and synthesized. In an aqueous solution, P1 shows a “turn-on” fluorescence response for Zn2+ and Cd2+ with a 50 nm blue shift. Furthermore, both P1-Zn2+ and P1-Cd2+ complexes were found to respond to pyrophosphate (PPi) over other important biological anions via a fluorescence quenching effect. P1 is also capable of monitoring intracellular Zn2+ and PPi in real time.

A novel amphiphilic imidazolium-based probe containing a dansyl fluorophore and a long cetyl chain has been developed for ATP recognition. The probe forms self-assembled micelle-like aggregates at low concentration in its aqueous solution and can selectively recognize ATP among other bioactive anions with a significant enhancement in fluorescence emission.