High-performance enzyme-free glucose and hydrogen peroxide sensors based on bimetallic AuCu nanoparticles coupled with multi-walled carbon nanotubes

Interest in designing and manufacturing non-enzymatic biosensors is growing which stimulates the increased research efforts to explore innovative nanocomposites with highly catalytic activity. Here, the development of high-performance non-enzymatic glucose and hydrogen peroxide (H2O2) sensors based on bimetallic AuCu nanoparticles coupled with multi-walled carbon nanotubes (AuCu@MWCNTs) was achieved in this work. They were investigated by the cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA) methods separately. Benefiting from the synergistic effects of AuCu@MWCNTs, the proposed biosensors exhibited excellent performance such as low detection limits (1.3 nM for glucose, 0.1 nM for H2O2), broad linear ranges (8 nM-60 mM for glucose, 1 nM-4 mM for H2O2) and high sensitivities (362.3 mu A center dot mM- 1 center dot cm- 2 for glucose, 1335 mu A center dot mM- 1 center dot cm- 2 for H2O2). Besides, the AuCu@MWCNTs based electrodes provided excellent stability, repeatability and reproducibility. Based on the outstanding performance, they exhibited good reliability and accuracy in the detection of glucose in goat serum samples and real-time monitoring of H2O2 released by living cells. The present work suggests that the fabricated biosensor holds great potential for non-enzymatic glucose determination and real-time quantitative detection of H2O2 in biomedical applications.