The structural properties of 5-methyl-2-phenyl-2H-1,2,3-triazole-4- carboxylic acid and chromogenic mechanism on its rhodamine B derivatives to Hg2+ ions

Tetraphenylethene-Modified Colorimetric and Fluorescent Chemosensor for Hg2+ With Aggregation-Induced Emission Enhancement, Solvatochromic, and Mechanochromic Fluorescence Features

A tetraphenylethene (TPE)-modified rhodanine derivative was successfully designed and prepared, and this luminophor showed intramolecular charge transfer nature from the TPE unit to the rhodanine-3-acetic acid unit. Interestingly, this luminogen not only exhibited typical aggregation-induced emission enhancement (AIEE) behavior but also showed good cell imaging performance. Remarkably, this AIEE-active TPE-containing rhodanine derivative possessed noticeable solvatochromic fluorescence effect involving multiple fluorescent colors of green, yellow-green, yellow, orange, and red. Meanwhile, this fluorescigenic compound displayed reversible mechanochromic fluorescence behavior based on the mutual transformation of between stable crystalline and metastable amorphous states. On the other hand, this multifunctional fluorophor could selectively and sensitively detect Hg²⁺ in an acetonitrile solution. Furthermore, this chemosensor could also be used to detect Hg²⁺ on test paper strips.

A new 1,2,3-triazole and its rhodamine B derivatives as a fluorescence probe for mercury ions

A newly synthesized compound, 5-methyl-1-phenyl-1H-1,2,3-triazole-4- carboxylic acid (MPC) was analyzed for its quantum chemical parameters and theoretical spectrum by computational chemistry. The calculated spectrum was in accord with the experimental measurements in a great degree. Then MPC was successfully designed and synthesized to a novel rhodamine B derivative RMPC. The RMPC exhibited about a 4000-fold increase in fluorescence intensity in the presence of Hg²⁺ ions over most other competitive metal ions. The triazole appended colorless chemodosimeter RMPC turns to pink upon the complex formation only with Hg²⁺ ions as a 1: 2 M ratio and enables naked-eye detection. The coordination mechanism of turning on/off fluorescence for Hg²⁺ ions were well proposed by explaining Hg²⁺ inducing the ring-opened rhodamine B moiety. The fluorescence imaging experiments of Hg²⁺ in HeLa cell demonstrated that the probe was labeled and it could be used in biological systems.

The specific binding of a new 1,2,3-triazole to three blood proteins and it's appended rhodamine complex for selective detection of Hg2

A synthesized compound, ethyl 2,5-diphenyl-2H-1,2,3-triazole-4- carboxylate (EDTC) was investigated on its physiochemical parameters and structural properties by using the quantum-chemical method. The results on the theoretical spectrum of EDTC were line with experimental fluorescence and absorption spectrum in large degree. Then EDTC was successfully synthesized to a novel rhodamine-based fluorescent probe (REDTC), which showed a distinct fluorescence enhancement upon the presence of Hg²⁺ in dimethyl formamide-water (DMF-H₂O) buffer solution (pH 7.4). Meanwhile, the triazole appended colorless compound turns to pink upon complex formation with Hg²⁺ ions as 1:2 molar ratios and enables naked-eye detection. The chromogenic mechanism was determined by using spectroscopic measurements and TD DFT calculation. The fluorescence imaging experiments of Hg²⁺ in HeLa cell revealed that the probe REDTC could be labeled and it could be used in biological systems. Also, the intermediate EDTC was developed as a sensitive fluorescent probe for specific studies on the interactions to three kinds of blood proteins including human serum albumin (HSA), human immunoglobulin (HIg) and bovine hemoglobin (BHb) by using a series of spectroscopic methods and molecular docking under the simulative physiological conditions. The interactions between EDTC and these proteins led to the distinct fluorescence enhancement. The thermodynamic measured results further suggested that hydrophobic forces play a dominating role in stabilizing the complexes, which are in correspondence with the results from molecular docking. The UV-visible, synchronous, and three-dimensional (3D) fluorescence measurements demonstrated that EDTC influences the conformational of proteins and the microenvironment surrounding HSA, HIg, or BHb in aqueous solution.

A solvent-dependent chemosensor for fluorimetric detection of Hg2+ and colorimetric detection of Cu2+ based on a new diarylethene with a rhodamine B unit

A novel solvent-dependent chemosensor based on a diarylethene derivative for fluorescent “turn-on” recognition of Hg²⁺ and colorimetric detection of Cu²⁺ was synthesized, its multi-controllable photoswitchable behaviors with light and chemical stimuli were investigated.