Direct Electron Transfer of Glucose Oxidase on Pre-Anodized Paper/Carbon Electrodes Modified through Zero-Length Cross-Linkers for Glucose Biosensors

Abstract

A disposable paper-based glucose biosensor with direct electron transfer (DET) of glucose oxidase (GOX) was developed through simple covalent immobilization of GOX on a carbon electrode surface using zero-length cross-linkers. This glucose biosensor exhibited a high electron transfer rate (ks, 3.363 s−1) as well as good affinity (km, 0.03 mM) for GOX while keeping innate enzymatic activities. Furthermore, the DET-based glucose detection was accomplished by employing both square wave voltammetry and chronoamperometric techniques, and it achieved a glucose detection range from 5.4 mg/dL to 900 mg/dL, which is wider than most commercially available glucometers. This low-cost DET glucose biosensor showed remarkable selectivity, and the use of the negative operating potential avoided interference from other common electroactive compounds. It has great potential to monitor different stages of diabetes from hypoglycemic to hyperglycemic states, especially for self-monitoring of blood glucose.

Magnetically Stimulated Bio‐ and Electrochemical Systems: State‐of‐the‐Art, Applications, and Future Directions

“…[64,65] On the other hand, in some particular cases, the MET approach was successfully implemented for highly sensitive and active biosensors. [66,67] To date, there are few significative reports approaching the DET from the use of microbes, [68][69][70][71] however about 100 enzymes, including alcohol dehydrogenase (ADH), [58] fructose dehydrogenase (FDH), [72] cytochrome c (Cyt c), [73,74] and glucose oxidase (GOx) [75,76] are known to be capable of working in DET conditions. In the case of GOx, it has been reported that single layers of carbon atoms can decrease the long distance between the electrode surface and its active site (FAD/FADH 2 cofactor), leading to a higher specific surface area and fast rates of DET.…”

The Importance of Spin‐Polarized Charge Reorganization in the Catalytic Activity of D‐Glucose Oxidase

“…This electron transfer process was previously studied in detail. [28,29,30,31] In this work we hypothesized that this electron transfer, within the GOx protein, is spin selective.…”