Study of electrochemical biosensor for determination of glucose based on Prussian blue/gold nanoparticles-chitosan nanocomposite film sensing interface

Abstract A highly electroactive bilayer composite film sensing interface of Prussian blue (PB)/gold nanoparticles-chitosan (AuNPs-CS) was modified on Au electrode through electrochemical deposition and coating method followed by integrating glucose oxidase (GO x ) into the interfacial matrix to fabricate a high-performance glucose biosensor. The excellent electrocatalytic ability of the PB/AuNPs-CS composite film sensing interface for H 2 O 2 was evaluated, which has a broad linear response of 0.01–7.95 mM, with a low detection limit (LOD) 0.269 μM and a high sensitivity of 511.82 μA·mM −1 ·cm −2 . The enhanced electrocatalytic activity of this sensing interface for H 2 O 2 is attributed to the protection from the network CS film to PB and the synergistic effect of PB and AuNPs. Consequently, an electrochemical biosensing interface was constructed with GO x immobilized as a model enzyme. The PB/GO x -AuNPs-CS biosensing nanocomposite film was capable of a fast steady-state response time (within 2 s) and high sensitivity to glucose with a wide linear range of: 0.025–2.00 mM ( R 2 = 0.99), with a sensitivity of 40.41 μA·mM −1 ·cm −2 and a LOD of 1.62 μM; and 2.00–6.50 mM ( R 2 = 0.98), with a sensitivity of 8.90 μA·mM −1 ·cm −2 and a LOD of 7.16 μM. The biosensor has good anti-interference and selectivity, which provides a promising wide linear range platform for clinical blood glucose detection in the future.