Peroxidase-like Au@Pt nanozyme as an integrated nanosensor for Ag+ detection by LSPR spectroscopy

• Published in: Talanta (Oxford) 2021-01, Vol.221, p.121627, Article 121627
• Main Authors: Tian, Yueyue, Chen, Yancao, Chen, Mei, Song, Zhi-Ling, Xiong, Bin, Zhang, Xiao-Bing
• Format: Article
• Language: English
• Subjects: Ag+ detection; Gold; Hydrogen Peroxide; LSPR spectroscopy; Nanosensor; Nanozyme; Peroxidase; Silver; Spectrum Analysis
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2020.121627

Here we report the peroxidase-like Au@Pt nanozyme as an integrated nanosensor for selective detection of silver ions (Ag+), where the nanozyme plays the roles as both the signal trigger and reporter simultaneously. This method relies on two critical chemical reactions, including (1) the unique inhibitory effect of Ag+ on the nanozyme triggered H2O2 decomposition at weak acid environment and (2) H2O2 induced Ag+ reduction onto the nanozyme surface at basic environment, leading to a blueshift in the localized surface plasmonic resonance wavelength (LSPR λmax) of the nanosensor. With this simple strategy, we demonstrated the sensitive and selective detection of Ag+ over a dynamic range from 0.5 to 1000 μM with a limit of detection (LOD) of 500 nM by UV–visible spectroscopy, which is below the permitted level of Ag+ in drinking water by U.S. Environmental Protection Agency (EPA). This method also exhibits satisfying recovery efficiency for Ag+ detection both in tap water and spring water from the Yuelu Mountain. With this satisfying sensing performance and excellent stability of nanoprobes, this strategy is promising for the detection of Ag+ in environment monitoring and food safety analysis. The peroxidase-like Au@Pt nanozyme was proposed as a novel integrated nanosensor for selective and sensitive detection of Ag+ by LSPR spectroscopy, which relies on the unique inhibitory effect of Ag+ on the nanozyme triggered H2O2 decomposition at weak acid environment and residual H2O2 induced Ag+ reduction onto the nanozyme surface at basic environment. [Display omitted] •The unique inhibitory effect of Ag+ on the Au@Pt nanozyme triggered H2O2 decomposition was disclosed.•A new nanosensor was constructed with Au@Pt nanozyme which acts as the signal trigger and reporter.•Facile Ag+ sensing by LSPR spectroscopy with satisfying sensing performances was achieved.