Structure and properties of porous composite membranes of regenerated silk fibroin and poly(vinyl alcohol) and biosensing of glucose via Meldola blue dispersed in polyester ionomer as an electron transfer mediator

Abstract

Porous composite membranes of regenerated silk fibroin and poly(vinyl alcohol) were prepared by adding polyethyleneglycol to the composite solution to reduce the mass-transfer resistance to the diffusion of substrate material transport; their surfaces were visualized with scanning electron microscopy. An amperometric glucose biosensor employing Meldola blue dispersed in polyester ionomer as electron transfer mediator was prepared to test the feasibility and workability of the composite membrane as immobilization matrix for glucose oxidase. The cationic exchange property of the polyester ionomer was employed to provide high local concentrations of Meldola blue (MB⁺) in the polymer film via ion exchange. Performance and characteristics of the glucose biosensor were evaluated with respect to response time, detection limit, applied potential, thickness of polyester ionomer membrane, pH and temperature. The glucose biosensor possesses a variety of advantages including easy maintenance of enzyme, simplicity of construction, fast response time and high stability.