Enhancement of the Peroxidase-Like Activity of Iodine-Capped Gold Nanoparticles for the Colorimetric Detection of Biothiols

Biosensors

Chia-Chen Chang¹  Chie-Pein Chen²  Chen-Yu Chen²  Tsz-Lian Hsu² 

[1] Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan City 333, Taiwan;Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei City 104, Taiwan;

关键词: colorimetric assay;    catalytic gold nanoparticle;    iodine;    peroxidase-like activity;   

DOI  :  10.3390/bios10090113

来源: DOAJ

【 摘 要 】

A colorimetric assay was developed for the detection of biothiols, based on the peroxidase-like activity of iodine-capped gold nanoparticles (AuNPs). These AuNPs show a synergetic effect in the form of peroxidase-mimicking activity at the interface of AuNPs, while free AuNPs and iodine alone have weak catalytic properties. Thus, iodine-capped AuNPs possess good intrinsic enzymatic activity and trigger the oxidation of 3,3’,5,5’-tetramethylbenzidine (TMB), leading to a change in color from colorless to yellow. When added to solution, biothiols, such as cysteine, strongly bind to the interface of AuNPs via gold-thiol bonds, inhibiting the catalytic activity of AuNPs, resulting in a decrease in oxidized TMB. Using this strategy, cysteine could be linearly determined, at a wide range of concentrations (0.5 to 20 μM), with a detection limit of 0.5 μM using UV-Vis spectroscopy. This method was applied for the detection of cysteine in diluted human urine.

【 授权许可】

Unknown