Ag+‐Gated Surface Chemistry of Gold Nanoparticles and Colorimetric Detection of Acetylcholinesterase

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 14; no. 31; pp. e1801680 - n/a
• Main Authors: Zhang, Jiangjiang, Zheng, Wenshu, Jiang, Xingyu
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 02.08.2018
• Subjects: acetylcholinesterase detection; Ascorbic acid; Cetyltrimethylammonium bromide; Colorimetry; Gold; gold nanoparticles; Nanomaterials; Nanoparticles; Nanotechnology; Organic chemistry; Peroxidase; peroxidase activity; Sensitivity enhancement; Silver; Surface chemistry; peroxidase activity; surface chemistry; gold nanoparticles; acetylcholinesterase detection
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201801680

Chemical regulation of enzyme‐mimic activity of nanomaterials is challenging because it requires a precise understanding of the surface chemistry and mechanism, and rationally designed applications. Herein, Ag+‐gated peroxidase activity is demonstrated by successfully modulating surface chemistry of cetyltrimethylammonium bromide‐capped gold nanoparticles (CTAB‐AuNPs). A surface blocking effect of long‐chain molecules on surfaces of AuNPs that inhibit peroxidase activity of AuNPs is found. Ag+ ions can selectively bind on the surfaces of AuNPs and competitively destroy CTAB membrane forming Ag+@CTAB‐AuNPs complexes to result in enhanced peroxidase activity. Ag+@CTAB‐AuNPs show the highest peroxidase activity compared to similar‐sized citrate‐capped and ascorbic acid‐capped AuNPs. Ag+@CTAB‐AuNPs can potentially develop into analyte‐responsive systems and exhibit advantages in the optical sensing field. For example, the Ag+@CTAB‐AuNPs system shows an enhanced sensitivity and selectivity for acetylcholinesterase activity sensing compared to other methods. Knock, knock! Ag+‐gated surface chemistry of cetyltrimethylammonium bromide‐gold nanoparticles (CTAB‐AuNPs) opens a door to better understanding the chemical regulation of enzymatic activity of nanomaterial. A simple but efficient, analyte‐responsive system of Ag+@CTAB‐AuNPs enables the sensitive and selective detection of acetylcholinesterase activity.