Silk/polyols/GOD microneedle based electrochemical biosensor for continuous glucose monitoring

This work illustrates the feasibility of a microneedle based electrochemical biosensor for continuous glucose monitoring. The device consists of three silk/d-sorbitol pyramidal microneedles integrated with platinum (Pt) and silver (Ag) wires and immobilized glucose selective enzyme (glucose oxidase, GOD) during fabrication. The silk/d-sorbitol composite can provide a biocompatible environment for the enzyme molecules. The break strength can be controlled by the ratio of silk to d-sorbitol, which guarantees microneedle penetrate into skin. The enzymatic-amperometric responses and glucose concentration were linearly correlated, and cover physiological conditions. The microneedle displays high stability both in long-term monitoring and storage, even at 37 °C. Our results reveal that this new microneedle biosensor is a promising tool for wearable minimally invasive continuous glucose monitoring in practical applications.