Xuefang Shang

Synthesis and cytotoxicity of azo nano-materials as new biosensors for L-Arginine determination.

Inspired from biological counterparts, chemical modification of azo derivatives with function groups may provide a highly efficient method to detect amino acid. Herein, we have designed and prepared a series of azo nano-materials involving -NO2, -COOH, -SO3H and naphthyl group, which showed high response for Arginine (Arg) among normal twenty kinds of (Alanine, Valine, Leucine, Isoleucine, Methionine, Aspartic acid, Glutamic acid, Arginine, Glycine, Serine, Threonine, Asparagine, Phenylalanine, Histidine, Tryptophan, Proline, Lysine, Glutamine, Tyrosine and Cysteine). Furthermore, theoretical investigation further illustrated the possible binding mode in the host-guest interaction and the roles of molecular frontier orbitals in molecular interplay. In addition, nano-material 3 exhibited high binding ability for Arg and low cytotoxicity to KYSE450 cells over a concentration range of 5-50μmol·L(-1) which may be used a biosensor for the Arg detection in vivo.

The development and amino acid binding ability of nano-materials based on azo derivatives: Theory and experiment

Two nano-material-containing azo groups have been designed and developed, and the binding ability of nano-materials with various amino acids has been characterized by UV-vis and fluorescence titrations. Results indicated that two nano-materials showed the strongest binding ability for homocysteine among twenty normal kinds of amino acids (alanine, valine, leucine, isoleucine, methionine, aspartic acid, glutamic acid, arginine, glycine, serine, threonine, asparagine, phenylalanine, histidine, tryptophan, proline, lysine, glutamine, tyrosine and homocysteine). The reason for the high sensitivity for homocysteine was that two nano-materials containing an aldehyde group reacted with SH in homocysteine and afforded very stable thiazolidine derivatives. Theoretical investigation further illustrated the possible binding mode in host-guest interaction and the roles of molecular frontier orbitals in molecular interplay. Thus, the two nano-materials can be used as optical sensors for the detection of homocysteine.

Synthesis and Binding Ability of Molecular Probes Based on a Phenanthroline Derivative: Theory and Experiment

A fluorescent and colorimetric molecular probe containing phenol groups has been designed and synthesized. The anion binding ability was evaluated for biolgically important anions (F−, Cl−, Br−, I−, AcO− and H2PO4−) by theoretical investigation, UV-Vis and fluorescence spectroscopy and 1H-NMR titration experiments. Results indicated the probe showed strong binding ability for H2PO4− without the interference of other anions tested and the interaction process was accompanied by color changes. Theoretical investigation analysis revealed that intramolecular hydrogen bonds existed in the structure of the probe and the roles of molecular frontier orbitals in molecular interplay were determined.

The Synthesis and Anion Recognition Property of Symmetrical Chemosensors Involving Thiourea Groups: Theory and Experiments

The synthesis of four symmetrical compounds containing urea/thiourea and anthracene/nitrobenzene groups was optimized. N,N’-Di((anthracen-9-yl)-methylene)thio-carbonohydrazide showed sensitive and selective binding ability for acetate ion among the studied anions. The presence of other competitive anions including F−, H2PO4−, Cl−, Br− and I− did not interfere with the strong binding ability. The mechanism of the host-guest interaction was through multiple hydrogen bonds due to the conformational complementarity and higher basicity. A theoretical investigation explained that intra-molecular hydrogen bonds existed in the compound which could strengthen the anion binding ability. In addition, molecular frontier orbitals in molecular interplay were introduced in order to explain the red-shift phenomenon in the host-guest interaction process. Compounds based on thiourea and anthracene derivatives can thus be used as a chemosensor for detecting acetate ion in environmental and pharmaceutical samples.

Colorimeric and fluorescence ON–OFF probe for acetate anion based on thiourea derivative: Theory and experiment

Based on thiourea moiety, three colorimetric and fluorescent anion probes have been synthesized. Results indicated the probe 1 containing p-NO(2) group showed the strongest binding ability for AcO(-) among the anions tested (F(-), AcO(-), H(2)PO(4)(-), Cl(-), Br(-), I(-)), which was not influenced by the existence of other anions. The interaction of host-guest was accompanied with a dramatic color change from colorless to orange. However, the addition of various anions did not cause noticeable spectral response of the probes (2 and 3) containing o, m-NO(2) groups. Theoretical investigation demonstrated the electron transition of the highest LUMO aroused the red-shift phenomenon in UV-vis spectra of 1-anion.

Synthesis, binding ability, and cell cytotoxicity of fluorescent probes for l-arginine detection based on naphthalene derivatives: Experiment and theory

Inspired by biological related parts, Schiff base derivatives and functional groups of chemical modification can provide efficient detection method of amino acids. Therefore, we have designed and prepared 4 compounds based on Schiff base derivatives involving ─NO2, ─OH, and naphthyl group. Results indicated that compound 4 containing 2 nitro groups showed strong sensitivity and high selectivity for arginine (Arg) among normal 18 kinds of standard amino acids (alanine, valine, leucine, isoleucine, methionine, aspartic acid, glutamic acid, arginine, glycine, serine, asparagine, phenylalanine, histidine, tryptophan, proline, lysine, glutamine, and cysteine). Theoretical investigation also approved the strong binding ability of compound 4 for Arg. In addition, compound 4 displayed high combining ability of Arg and low cytotoxicity of MCF‐7 cell in the 0 to 150 μg mL−1 of concentration range; it can be used for Arg in vivo detection of fluorescent probe.

A Highly Selective Colorimetric Sensor for Cysteine in Water Solution and Bovine Serum Albumin

A simple colorimetric sensor, 2-bromonaphthalene-1,4-dione, has been developed for the Cysteine detection. The sensor showed its best performance in a mixture of ethanol and HEPES (5 : 5, v/v) solution at pH of 7.0. The results of UV-vis and fluorescence indicated that 2-bromonaphthalene-1,4-dione was selective and sensitive for Cysteine detection without the interference of other amino acids (Cysteine, Alanine, Arginine, Aspartinie, Glutamine, Glycine, Histidine, Isoleucine, Leucine, Lysine, Methionine, Proline, Serine, Threonine, Phenylalanine, Valine, Tryptophan, and Hydroxyproline). 2-Bromonaphthalene-1,4-dione also showed binding ability for Cysteine in bovine serum albumin and could be used as a potential colorimetric sensor among eighteen kinds of natural amino acids. Importantly, the recognition of CySH could be observed by naked eye.

THE DIFFERENT RECOGNITION MECHANISM OF CARBAZOLE DERIVATIVES FOR BIOLOGICAL IMPORTANT ANION: THEORY AND EXPERIMENT

Two fluorescent anion sensors bearing phenol, carbazole-NH and –NO 2 group were designed and synthesized. They both exhibited highly binding ability for H 2 PO 4 − among the anions tested. In the presence of H 2 PO 4 −, the fluorescence of the sensors underwent a dramatic enhancement, while the presence of other anions such as F−, AcO−, Cl−, Br−, and I−, had weak or no effect on the fluorescence. The determination limit of two sensors ( 1 and 2) toward H 2 PO 4 − were 3.0×10−7 and 5.0×10−7 mol·L-1, respectively. Theoretical investigation indicated it was the highest HOMO to induce the red-shift phenomena of two sensors.

Highly selective probes of copper(II) complexes for sulfide detection and cytotoxicity assay

ABSTRACT Two probes based on novel Copper(II) complexes were developed in order to obtain H2S molecular probes with higher selectivity. The molecular structures of the complexes were characterized by 1H NMR, HRMS, IR and elemental analysis. The interaction of the compounds with biologically important anions and amino acids was determined by UV-vis and Fluorescence titration experiments. Results indicated that the compounds showed the highest binding ability for HS− among studied anions (AcO−, H2PO4−, F−, Cl−, Br− and I−) and amino acids (GSH, HCys and Cys) accompanied by blue shift phenomenon in pure DMSO and aqueous solution. The possible mechanism of host–guest interaction may be that the Copper(II) ion of complex was captured by HS− and free ligand released which showed a remarkable changes in UV-vis absorption. In addition, cytotoxicity of the synthesized compounds was studied on MCF-7 cells. Results indicated that the synthesized compounds had low cytotoxicity over a concentration range of 0–150 µg⋅mL−1, which exhibited that the synthesized probes could be used to detect H2S in vivo. The probes based on novel copper(II) complexes were synthesized and obtained by the reaction of substituent salicylaldehyde with amine derivatives, and then reacted with Cu(CH3COO)2·H2O, respectively. Investigation on the interference from other species suggested that copper(II) complexes have high selectivity for HS− over other anions (AcO−, , F−, Cl−, Br− and I−), followed by the release of the copper ion to give a remarkable increase in UV–VIS absorption in pure DMSO solution and aqueous solution. GRAPHICAL ABSTRACT

Synthesis and crystal structure of a highly selective colorimetric and fluorometric sensor for hydrogen sulfide

A novel Cu(II) complex chemosensor for hydrogen sulfide with azo as the colorimetric group has been synthesized. The complex and ligand crystals were obtained and the molecular structures were characterized by X-ray diffraction and Electrospray ionization High resolution mass spectrometer (ESI-HRMS). The photophysical and recognition properties were examined. The complex can recognize S2- , with an obvious color change from yellow to red based on a copper ion complex displacement mechanism. By contrast, no obvious changes were observed in the presence of other anions (AcO- , H2 PO4- , F- , Cl- , Br- and I- ). We present a simple, easily prepared, yet efficient, inorganic reaction-based sensor for the detection of S2- . The complex should have many chemical and analytical applications in the sensing of hydrogen sulfide.