Multilayer sensing platform: gold nanoparticles/prussian blue decorated graphite paper for NADH and H2O2 detection

Abstract

In this study, an exfoliated graphite paper (EGP) was employed as a supported electrode for prussian blue (PB) and gold nanoparticles (AuNPs) modification to fabricate a novel electrochemical sensor. The scanning electron microscopy image showed the multilayer structure of the sensor with PB and AuNPs uniform coating. Due to the high surface area and good conductivity of the multilayer structure, as well as the conductivity of AuNPs, the prepared sensor exhibited an obvious improvement for sensitive detection of nicotinamide adenine dinucleotide (NADH) with a linear range of 5.0 × 10⁻⁷ mol L⁻¹–1.0 × 10⁻³ mol L⁻¹. Moreover, the modified PB film endowed the sensor with good electrocatalytic activity for hydrogen peroxide (H₂O₂) sensing. Under the optimal conditions, the linear range and limit of detection for H₂O₂ sensitive detection were 5.0 × 10⁻⁸ mol L⁻¹–1.0 × 10⁻³ mol L⁻¹ and 4.8 × 10⁻⁹ mol L⁻¹, respectively. The sensor can also be used for detection in real samples with satisfactory results. The advantages of low-cost, easy modification, multilayer structure, and good conductivity made the EGP an alternative candidate for supported electrode materials in the preparation and application of various electrochemical sensors.