Indicator approach to develop a chemosensor for the colorimetric sensing of thiol-containing water and its application for the thiol detection in plasma

Abstract

A strategy for the determination of the presence of thiol-containing amino acids was successfully established by simply assembling copper chloride and xylenol orange (3,3'-bis[N,N-bis(carboxymethyl)aminomethyl]-o-cresolsulfonephthalein trisodium salt; XO) in a 1 : 1 molar ratio in quasi-physiological water solution (pH 6.0). The copper(II)-XO ensemble was highly selective for thiol species such as cysteine, homocysteine, and glutathione without interference from other amino acids and could quantitatively detect thiol in the range from 10 to 200 μM with a linear relationship having an average molar absorbance constant of 6530 L mol(-1) cm(-1) in pure water. The whole recognition process for thiol gave rise to a rapid visual color change from purple-red to yellow which can be observed simultaneously with the naked-eye.

Synthesis and Application of an Aldazine-Based Fluorescence Chemosensor for the Sequential Detection of Cu2+ and Biological Thiols in Aqueous Solution and Living Cells

“…Recently, more attention has been paid to indicator displacement assays based on a simple competition mechanism between an indicator and analytes [ 47 , 48 ]. For the displacement strategy, the receptor is non-covalently attached to the indicator (cation) forming a so-called chemosensing ensemble, which is non-fluorescent due to metal ion-induced fluorescence quenching.…”

An off–on fluorescent probe based on maleimide for detecting thiols and its application for bioimaging

“…In our recent work, we have reported a few fluorescent probes for the detection of biothiols [25][26][27]29,52]. As an extension of our work, herein, we report a new type fluorescent probe containing binaphthalene fluorophore and maleimide binding group (1) based on Michael addition reaction, which displays a linear fluorescence change to afford the quantitative detection of biothiols by the thiol-maleimide coupling reaction.…”

An azo based colorimetric probe for the detection of cysteine and lysine amino acids and its real application in human blood plasma

“…To release the protein-bound thiols, the disulde bonds were reduced by a vigorous mixing of blood plasma (100 ml) with an appropriate amount sodium borohydride (0.5 mM) followed by incubation for 3 min at room temperature. 24,25 This plasma solution was used for interaction and titration studies with our probes 3a and 3b (10 mM) and we followed the changes in the UV-visible absorption spectra. Upon the addition of human blood plasma (10 ml) to a solution of 3a in a HEPES buffer the bands centered at 542 nm (3 ¼ 6.4 Â 10 4 mol À1 cm À1 ) and 413 nm (3 ¼ 1.8 Â 10 4 mol À1 cm À1 ) diminished and new bands appeared at 570 nm (3 ¼ 1.8 Â 10 4 mol À1 cm À1 ) and $395 nm (3 ¼ 3.0 Â 10 4 mol À1 cm À1 ).…”