Tyrosinase Incorporated with Au-Pt@SiO₂ Nanospheres for Electrochemical Detection of Bisphenol A

Based on tyrosinase modified Au-Pt@SiO 2 /Au-graphene (APS/Au-GN) electrode, a highly sensitive biosensor was developed for the direct electrochemical detection of bisphenol A (BPA) in food matrices. In this work, Au-graphene (Au-GN), Au-Pt@SiO 2 nanocomposites (APS NPs) and tyrosinase (Tyr) were subsequently cast on glass carbon electrode (GCE) via the electrostatic interaction and Van der Waals force. The self-assembled APS NPs and Tyr were decorated on Au-GN forming a new hierarchical three dimensional nanostructure. Due to the dense Au/Pt dots distributed on silica nanoparticles, APS NPs could behave excellent catalytic activity and stability. In this regard, BPA could be sensitively detected by square wave voltammetry (SWV) and differential pulse voltammetry (DPV) with well-defined oxidation peaks at 480 mV and 660 mV, respectively. Under the optimal conditions, SWV detection behaved good analytical performance toward BPA with a wide linear response ranging from 0.01 mg L −1 to10 mg L −1 . The detection limit of APS/Au-GN/GCE for BPA was 1.80 μg L −1 (S/N = 3). Moreover, the method showed good reproducibility in practical samples with recoveries from 87.4% to 110.7%, suggesting its potential application in food analysis and safety verification.