Comparison of Triangular Silver Nanoprisms with Different Capping Agents and Structural Size for H2O2 Etching-Based Biosensors

Abstract

This study compared the susceptibility of different triangular silver nanoprisms (TSNPRs) towards the etching of hydrogen peroxide (H2O2), a catalytical product of glucose oxidase (GOx). The influence of capping agents and structural size have been explored towards the oxidation of silver nanoprisms. Results indicated that the etching of the TSNPRs was extremely effected by surface capping agents, in which citrate contributed a highest H2O2-sensitive effect in the absence of secondary capping ligands (e.g., glycerol and ethanol). Meanwhile, compared to bigger TSNPRs, smaller nanoprisms exhibited a different signal output of plasma resonance peak through intensity decrease rather than wavelength shift, making them more H2O2-etching susceptibile. In virtue of GOx etching-based system, TSNPRs with a small size and citrate capping were served as a substitute for big nanoprisms to sense glucose, offering a number of advantages such as high sensitivity, improved calibration, time-saving and extended detection ranges. Moreover, the small sized TSNPRs capping with citrate alone have been expected to be of great interest in the trace of GOx, providing an ultrahigh sensitive GOx etching-based analytical platform for point-of-care diagnostics towards other analytes (e.g., DNA, protein).