Enhanced peroxidase-like activity of MoS2/graphene oxide hybrid with light irradiation for glucose detection

Abstract

Construction of novel enzyme-free mimetic is very important in improving the sensitivity of biosensor. Here, an intrinsic peroxidase-like activity of MoS2 and graphene oxide (MoS2/GO) hybrid is demonstrated and the hybrid is also used to detect glucose with high sensitivity. Firstly, the peroxidase-like activity of hydrid is compared with that of two components alone, the mixture of two components and horseradish peroxidase. The results show that the hydrid has highest catalytic activity and the Michaelis constant of this hybrid is 4.35 times lower and the maximal reaction velocity is 3.34 times higher than those of horseradish peroxidase, respectively. Electrochemical technologies are used to investigate the enhancing mechanism. The results show that the excellently catalytic performance could be attributed to the fast electron transfer on the surface of MoS2/GO and the synergistic interaction of two components. Secondly, the effect of visible light and near-infrared light on the peroxidase-like activity of hybrid is also investigated. The results show that the limit of detection for H2O2 can be reduced from 10nM to 2.5nM with visible light. Thirdly, the hybrid is further used to detect glucose in serum with and without light. The results show that the hybrid has high selectivity and sensitivity for glucose detection in serum and the limit of detection for glucose is reduced from 0.83μM to 65nM with visible light. Therefore, the hybrid may have a potential application in glucose detection in serum with high sensitivity and selectivity.