Au Nanoparticles@UiO-66 Composite Film-Coated Carbon Cloth Substrate for High-Performance H₂O₂ Electrochemical Sensing

Abstract

Due to the strong oxidizability of H₂O₂, rapid, accurate, sensitive, and stable sensors of hydrogen peroxide (H₂O₂) have attracted wide attention in the chemical industry, food, medicine, household detergents, and environmental monitoring fields. Here, a high-performance H₂O₂ electrochemical sensing platform is proposed based on an Au nanoparticles@UiO-66 film coated on a carbon cloth (CC) electrode (Au NPs@UiO-66/CC electrode). The Au NPs@UiO-66/CC electrode was prepared through solvothermal growth of a UiO-66 film on a functionalized three-dimensional CC electrode, followed by in situ deposition of Au NPs into the UiO-66 film under a periodic galvanostatic pulse current. The in situ preparation strategy greatly improves the electrical interaction between Au NPs@UiO-66 and the CC substrate without sacrificing the electrochemical activity of the Au NPs@UiO-66/CC electrode. Meanwhile, thanks to the high specific surface area of the three-dimensional Au NPs@UiO-66/CC electrode, the optimized Au NPs@UiO-66/CC electrode illustrates excellent electrochemical detection capability for H₂O₂ with an extensive linear range (0.1-21 mM), high sensitivity (1048.01 μA mM^-1 cm^-2), and lower limit of detection [0.033 μM (S/N = 3)] and limit of quantification [0.109 μM (S/N = 3)]. At the same time, the encapsulated structure of Au NPs in the UiO-66 film also endows the composite electrode with specific sensing performance owing to the regular opening channels of the UiO-66 films that prevent large-size interferents from reacting to the electrochemically active Au NPs. Together with all these advantages, the proposed sensing platform would exhibit great potential for electrochemical sensors and bioelectronics.