Enhanced Modification between Glucose Dehydrogenase and Mediator Using Epoxy Silane Assembly for Monitoring Glucose

Abstract

Blood glucose monitoring (BGM) using disposable electrodes is commonly used in healthcare diagnosis. The BGM method is not suitable for people with diabetes requiring real-time monitoring who might experience sudden hypoglycemia or hyperglycemia owing to a single measurement at a specific moment. This study aimed to achieve an enhanced stability of glucose diagnosis for continuous glucose measurement systems (CGMs). A representative mediator of a second-generation glucose sensor was synthesized and coordinated with a polymer for immobilization on an indium tin oxide (ITO) electrode. For electrode immobilization, an electrode for enhanced stability was fabricated using the silanization method. The morphological properties of the electrodes were confirmed via cyclic voltammetry (CV), impedance spectroscopy, and SEM. The loss rate of the current density was only 10.11% of the initial current after 8 d. The electrode exhibited a coefficient of determination of R2 = 0.9924, sensitivity of 1.5454 μA/cm2·mM, limit of quantitation (LOQ) of 7.604 μM, and limit of detection (LOD) of 2.509 μM for glucose concentrations between 0.1 and 20.0 mM. The electrode system developed in this study is applicable to the CGM healthcare industry and is expected to be applicable to biofuel cells.

Keywords

• continuous glucose monitoring
• mediator
• covalent binding