An electrochemical sensing platform amplified with a Au@Ag nanoparticle-decorated three-dimensional N-doped graphene aerogel for ultrasensitive determination of baicalein

Abstract

Noble bimetallic nanomaterials have aroused great interest in the field of electrochemistry for their special properties. Herein Au@Ag nanoparticles loaded on a three-dimensional (3D) N-doped graphene aerogel (NGA) were designed, synthesized, and used as electrode modifiers. The structure and composition of Au@Ag/3DNGA nanocomposite was characterized and confirmed using different techniques such as SEM, TEM, Raman, XRD, XPS and UV-vis, revealing that the N-doped 3D architecture was well formed with uniform size and core-shell like Au@Ag bimetallic nanoparticles anchored homogeneously. The Au@Ag/3DNGA nanocomposite was further modified on the surface of a carbon ionic liquid electrode (CILE) to get a novel sensing platform. Electrochemical behaviors of baicalein were investigated using Au@Ag/3DNGA/CILE as the working electrode, showing obviously enhanced performance compared to that on CILE and 3DNGA/CILE. Electrochemical reaction process of baicalein was investigated and the electrochemical parameters were calculated. Under the optimized conditions, the sensitive differential pulse voltammetric oxidation response of baicalein was used for ultrasensitive detection of baicalein with a wider calibration range of 1.0 × 10⁻³ ∼ 10.0 μmol L⁻¹ and a lower detection limit of 0.345 nmol L⁻¹ (3S₀/S). The proposed method could be successfully applied for baicalein analysis in dual yellow oral liquid with the recovery of 95.3–106.0%, showing reliable application.