A reversible competition colorimetric assay for the detection of biothiols based on ruthenium-containing complex

作者：Hao, Yuanqiang; Xiong, Dandan; Wang, Liqiang; Chen, Wansong; Zhou, Binbin; Liu, You-Nian^*

来源：Talanta, 2013, 115: 253-257.

DOI：10.1016/j.talanta.2013.04.076

• Reversible calorimetric assay
• Competitive ligation
• Ruthenium-containing dye
• Thiol detection

A novel reversible colorimetric sensor, which based on a competitive ligation of Hg2+ by thiols, cysteine (Cys) or glutathione (GSH), and thiocyanate (SCN) on the N3 dye (bis(4,4'-dicarboxy-2,2'-bipyridine) dithiocyanato ruthenium (II)), was developed for the detection of biothiols. First, Hg2+ ions coordinate to the sulfur atom of the dyes' SCN groups, and this interaction induces a change in color from red to yellow, owing to the formation of a complex of Hg2+-N3. Then, in the presence of biothiols, the red color of N3 is recovered concomitantly with the dissociation of the Hg2+-N3 complex, due to the extraction of Hg2+ by biothiols. Thus the corresponding color variation in the process of the dissociation of the Hg2+-N3 complex can be employed for the quantitative detection of thiols using UV-vis spectroscopy. In particular, the transformation can be readily viewed with the naked eye. A good linear relationship between the change in absorbance (Delta Abs) of Hg2+-N3 at 461 nm and the thiol concentration was obtained in the range of 0.5-25 mu M, and the detection limits are then calculated to be 57 and 52 nM for Cys and GSH, respectively. The proposed colorimetric assay displays a high selectivity for Cys over various other amino acids and GSSG (oxidized glutathione).

• 出版日期2013-10-15
• 单位中南大学