Silk-Fibroin as Biocompatible and Bioresorbable Enzyme Immobilization Matrix for Screen-Printed Amperometric Glucose Biosensors

Silk-fibroin is utilized as a biocompatible and bioresorbable enzyme immobilization matrix and exemplarily demonstrated for a screen-printed amperometric glucose biosensor. The silk-fibroin is derived from the silkworm Bombyx mori. The enzyme immobilization matrix consisting of silk-fibroin, together with glucose oxidase from Aspergillus niger, is applied to a screen-printed carbon-based, biocompatible, and biodegradable working electrode on a flexible silk-fibroin substrate. The biosensor is characterized electrochemically at physiological glucose concentrations in the range from 0.5 to 10 mm. The results are compared to a “conventional” glucose biosensor, also fabricated on a flexible silk-fibroin substrate, however utilizing a laboratory standard enzyme immobilization matrix based on bovine serum albumin and glutaraldehyde. Furthermore, the influence of pH (pH 5.5 to pH 8.0) and temperature variations (21 to 70 °C) on these two different immobilization matrices are studied.