A Highly Sensitive Glucose Biosensor Based on Gold Nanoparticles/Bovine Serum Albumin/Fe3O4 Biocomposite Nanoparticles

This study presents the synthesis and characterization of a novel glucose electrochemical biosensor based on gold nanoparticles/bovine serum albumin/Fe 3 O 4 (AuNPs/BSA/Fe 3 O 4 ) composite nanoparticles . The prepared magnetic composite nanoparticles consist of a BSA protein shell, providing biocompatible environment for enzyme immobilization. Furthermore, in situ immobilization of gold nanoparticles greatly enhances the performance of electron transfer. Using these composite nanoparticles, the model enzyme, glucose oxidase (GOx) was readily adsorbed to surface so as the GOx/AuNPs/BSA/Fe 3 O 4 electrochemical biosensor was developed. The electrochemical performance of the biosensor was characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry. Under the optimal preparation conditions, the resultant biosensor has a short response time of 0.8   s, an excellent sensitivity of 115.3   μA   mM −1   cm −2 , and a linear dynamic range from 0.25 to 7.0   mM with a low detection limit of 3.54   μM (S/N   =   3). The high sensitivity, good reproducibility and stability of the biosensor presented in this study show that the as-prepared AuNPs/BSA/Fe 3 O 4 composite nanoparticles are a promising material for the development and construction of biosensors.