Hg2+-mediated aggregation of gold nanoparticles for colorimetric screening of biothiols

作者：Xu, Hu; Wang, Yiwen; Huang, Xiaomei; Li, Yan; Zhang, Hua; Zhong, Xinhua^*

来源：Analyst, 2012, 137(4): 924-931.

DOI：10.1039/c2an15926k

• PERFORMANCE LIQUID-CHROMATOGRAPHY
• HIGHLY SENSITIVE DETECTION
• SELECTIVE DETECTION
• CAPILLARY-ELECTROPHORESIS
• AMPEROMETRIC DETECTION
• FLUORESCENT SENSOR
• HUMAN PLASMA
• AMINO-ACIDS
• ION HG2+
• CYSTEINE

In this work, we report a colorimetric assay for the screening of biothiols including glutathione (GSH), cysteine (Cys), and homocysteine (Hcys) based on Hg2+-mediated aggregation of gold nanoparticles (AuNPs). Hg2+ can induce aggregation of thiol-containing naphthalimide (1) capped AuNPs due to the cross-linking interactions from the resulting "thymine-Hg2+-thymine'' (T-Hg2+-T) analogous structure. When Hg2+ is firstly treated with biothiols, followed by mixing with 1-capped AuNPs suspension, AuNPs undergo a transformation from an aggregation to a dispersion state depending on the concentration of biothiols. This anti-aggregation or re-dispersion of AuNPs is due to the higher affinity of Hg2+ for biothiols relative to compound 1. The corresponding color variation in the process of anti-aggregation of AuNPs can be used for the quantitative screening of biothiols through UV-vis spectroscopy or by the naked eye. Under optimized conditions, a good linear relationship in the range of 0.025-2.28 mu M is obtained for GSH, 0.035-1.53 mu M for Cys, and 0.040-2.20 mu M for Hcys. The detection limits of this assay for GSH, Cys, and Hcys are 17, 9, and 18 nM, respectively. This colorimetric assay exhibits a high selectivity and sensitivity with tunable dynamic range. The proposed method has been successfully used in the determination of total biothiol content in human urine samples.

• 出版日期2012
• 单位华东理工大学