Hydrogen peroxide electrochemical biosensor constructed on the basis of Prussian blue/Au nanoparticles-chitosan nanocomposite membrane sensing interface

The development of sensing interfaces with high selectivity and sensitivity is a significant focus on electrochemical biosensor. A hydrogen peroxide biosensor with good properties is developed by constructing a Prussian blue (PB)/Au nanoparticles-chitosan (AuNPs-CS) highly electroactive bilayer composite membrane sensing interface on an Au electrode. The AuNPs-CHi nanocomplexes are assembled with PB via layer-by-layer assembly method to construct a CHi-AuNPs/PB sensing interface. Protection of PB by the network CS membrane and the synergistic effect of PB and AuNPs enhance the electrocatalytic activity of this sensing interface towards H₂O₂. The PB/AuNPs-CS composite membrane sensing interface has a steady-state response time of less than 2 s and high sensitivity to H₂O₂ with a linear response range of 0.01 ~ 7.95 μM, a low limit of detection of 0.269 μM (S/N = 3) and a sensitivity of 511.82 mA·mM-¹·cm-². The biosensor provides a platform to detecting H₂O₂ with a wide linear range and low detection limit for future rapid characterisation of relevant physiological information.