An amperometric Meldola Blue-mediated sensor high sensitive to hydrogen peroxide based on immobilization of horseradish peroxidase in a composite membrane of regenerated silk fibroin and poly(vinyl alcohol)

A new composite membrane of poly(vinyl alcohol) (PVA) and regenerated silk fibroin (RSF) was successfully employed to immobilize horseradish peroxidase (HRP) and infrared (IR) was used to get insight in the structure of the composite membrane. An amperometric HRP-based sensor highly sensitive to hydrogen peroxide was fabricated, which was based on Meldola Blue as a mediator to facilitate efficient electron transfer between immobilized HRP and a glassy carbon electrode. Performance and characteristics of the sensor were evaluated with respect to response time, detection limit, selectivity, operating and storage stability, and dependence on temperature, pH, applied potential and mediator concentration. The sensor displayed high sensitivity to hydrogen peroxide with low detection of limit of 0.1 μM.