Insights into enzymatic mimicking activity of silver nanoprisms: spectral monitoring and analysis

Peroxidase-like reaction process involving o-phenylenediamine (OPD) and silver nanoprisms in the presence of hydrogen peroxide (H 2 O 2 ) was monitored using time-resolved ultraviolet–visible (UV–Vis) absorption spectroscopy. The oxidation of OPD and etching of silver nanoprisms were investigated by analyzing the dynamic spectral data. Two-dimensional correlation spectroscopy (2D-COS) and principal component analysis (PCA) were employed to gain insights into the correlation between catalytic oxidation of OPD and etching of silver nanoprisms. It was found that OPD offered significant protection effect for silver nanoprisms so that morphologies of silver nanoprisms maintained at the beginning period after addition of H 2 O 2 . Moreover, silver nanoprisms accelerated the oxidation of OPD by H 2 O 2 , demonstrating enzymatic mimicking activity of silver nanoprisms. The combination of time-resolved UV–Vis absorption spectroscopy and spectral calculation methods could be used for exploration of complex reaction systems with spectral variations.