Periodic nanostructured Au arrays on an Si electrode for high-performance electrochemical detection of hydrogen peroxide without an enzyme

Abstract

Periodic gold nanosphere arrays were prepared on a planar silicon substrate, which could be directly developed as an electrode to sensitively and selectively detect H₂O₂ without an enzyme via an electrochemical method. The arrays of Au nanospheres were fabricated on a large scale (∼cm²) on the Si substrate using polystyrene (PS) colloidal monolayers as the template, after Au deposition and subsequent annealing. The developed biosensor based on the Au nanosphere arrays on the Si substrate demonstrated excellent catalytic activity towards H₂O₂ over a wide linear range of 0.2 μM–5 mM with a very low detection limit of 0.1 μM. Importantly, the electrochemical biosensor possessed good stability and high reproducibility. The catalytic activity can be enhanced by reducing the gold nanoparticle size and periodic length in the array. The biosensors based on periodic Au nanosphere arrays used to determine the concentration of H₂O₂ have the advantages of non-enzymatic detection and non-Pt electrode strategy when compared to the conventional method, which may open up new horizons in the production of outstanding biosensors and can be used as a platform for the preparation of various electrochemical biosensors.