Materials for Fabricating Biosensors for Transdermal Glucose Monitoring

Abstract

Most amperometric biosensors based on the metal-catalyzed electrooxidation of hydrogen peroxide (H2O2) combine an electrochemical sensor with an analyte-specific oxidase-type enzyme, e.g., glucose oxidase for the detection of glucose. H2O2 produced by the glucose oxidation is measured at a working electrode that has a platinum group metal catalyst. Improved long-term outcomes for diabetic subjects is improved by controlling blood glucose with frequent monitoring, i.e., more than five times per day. Transdermal extraction of interstitial fluid for glucose monitoring is an attractive approach to achieving this goal without the need to frequently draw blood samples by finger-pricking. Materials to fabricate blood glucose biosensors are often based on electron-transfer mediators that are not suitable for transdermal extraction because of their potential toxic effects. Furthermore, the glucose concentration in transdermally extracted fluid is typically ∼5 μmol/L vs ∼5 mmol/L in whole blood. This places a far greater demand on detection methods. A biosensor fabricated with pure platinum, printed on a ceramic substrate …