Enzyme-mediator coupling for non-invasive glucose monitoring

Abstract

The aim of this work was to modify the enzymes glucose oxidase (GOx) and glucose dehydrogenase (GDH) with electron relays for wearable glucose biosensor applications. The significance of glucose biosensors lies in their great impact on the field of diabetes management. The main drawback of the glucose biosensors that are currently on the market is their reliance on invasive blood sampling that causes pain and discomfort to people living with diabetes. Therefore, there is a need for non-invasive and wearable glucose biosensors for the management of diabetes. Most of the available glucose biosensors are amperometric enzymatic biosensors. The biosensors fabricated in this work that were modified with GOx utilized Prussian blue, ferrocenecarboxylic acid, and a Ru-complex as electron relays, while the biosensors that were modified with GDH utilized phenazine methosulfate (PMS), ferrocenecarboxylic acid, and a Ru-complex as electron relays. The analytical performance of the fabricated biosensors was mainly investigated with chronoamperometry and cyclic voltammetry. All the biosensors modified with GOx responded linearly to the glucose additions and showed potential as functioning glucose biosensors. Furthermore, the modification of GDH with PMS worked well and the biosensors responded linearly to the glucose additions. The attachment of molecular relays (ferrocenecarboxylic acid and the Ru-complex) to GDH did not work.