Fabrication of Ascorbic Acid Biosensor Based on Coupling Polyethylene Glycol Modified Silk Fibroin Membrane onto Glassy Carbon Electrode

摘要

Nowadays biosensors have been extensively used in a wide variety of applications especially in clinical works and food industry. In this work, a specific ascorbic acid (AA) biosensor was developed by immobilizing ascorbate oxidase (ASOD) on a polyethylene glycol (PEG) modified silk fibroin (SF) membrane then coupling to the glassy carbon electrode (GCE). The SF-PEG-ASOD membrane provided the highest enzyme activity in phosphate buffer at pH 5. As being the electrode, the SF-PEG-ASOD modified GCE displayed the highest response when it is operated under the condition of 0.40 mg/L of ASOD in phosphate buffer at pH 5. This biosensor provided both good linearity (r~2 = 0.999 in the range of 1.0-10.0 mM) and sensitivity with short response time (26s). It also exhibited good anti-interference ability with the storage time of 5 days without changing its initial response.