Colorimetric detections of iodide and mercuric ions based on a regulation of an Enzyme-Like activity from gold nanoclusters

Meiling Fu; Lan Li; Deyuan Yang; Yifeng Tu; Jilin Yan

doi:10.1016/j.saa.2022.121450

Colorimetric detections of iodide and mercuric ions based on a regulation of an Enzyme-Like activity from gold nanoclusters

Spectrochim Acta A Mol Biomol Spectrosc. 2022 Oct 15:279:121450. doi: 10.1016/j.saa.2022.121450. Epub 2022 May 31.

Authors

Meiling Fu¹, Lan Li¹, Deyuan Yang¹, Yifeng Tu¹, Jilin Yan²

Affiliations

¹ The Key Lab of Health Chemistry and Molecular Diagnosis of Suzhou, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Industrial Park, Suzhou 215123, China.
² The Key Lab of Health Chemistry and Molecular Diagnosis of Suzhou, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Industrial Park, Suzhou 215123, China. Electronic address: yanjl@suda.edu.cn.

PMID: 35679739
DOI: 10.1016/j.saa.2022.121450

Abstract

A simple colorimetric method was developed for sensitive and selective detections of I^- and Hg²⁺. Histidine stabilized gold nanoclusters (His-AuNCs) were synthesized and catalyzed the oxidation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) to a blue product. As a strong ligand toward gold, iodide (I^-) attached to the surface of the His-AuNCs and significantly enhanced the oxidase-like activity of the His-AuNCs. Based on this enhancement, a sensitive colorimetric response toward I^- was obtained. Furthermore, the strong interaction between Hg²⁺ and I^- was adopted for an indirect Hg²⁺ detection. Under the optimal conditions, the platform presented high selectivity for the determinations of I^- and Hg²⁺ in the ranges 0.02-1 µM and 0.05-0.8 µM, with detection limits as 3.3 nM and 8 nM respectively. This colorimetric assay was successfully applied for analysis of real samples.

Keywords: Catalysis; Enhancement; Gold nanoclusters; Iodide; Mecuric ion; Nanozyme.

MeSH terms

Colorimetry / methods
Gold
Iodides
Mercury* / analysis
Metal Nanoparticles*

Substances

Iodides
Gold
Mercury