Au@Cu2O composite nanorods as mimetic peroxidase for glucose colorimetric sensing

Abstract

Au@Cu2O composite nanorods (CNRs) were prepared by depositing Cu2O onto the surface of Au nanorods. The as-prepared Au@Cu2O CNRs exhibit enhanced peroxidase-like activity compared to bare Au NRs and Cu2O, and can effectively catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H2O2, resulting in the formation of a blue-colored oxidized TMB (ox-TMB). Thus, the feasibility of Au@Cu2O CNRs as a peroxidase mimic for H2O2 sensing was investigated through colorimetric method. Combined with glucose oxidase, a simple colorimetric method for glucose detection was further established, which exhibits good analytical performance, including a wide linear response range of 0.5 ∼ 140 µM, a low detection limit of 0.18 µM, and good selectivity. Most of all, the achieved satisfactory recovery (96.0 % ∼ 110.8 %) and precision (relative standard deviation less than 2.8 %) in serum samples confirm the potential of the developed method for practical applications.