Gold nanoparticles-coated eggshell membrane with immobilized glucose oxidase for fabrication of glucose biosensor

This work reports the fabrication and application of a glucose biosensor based on the catalytic effect of gold nanoparticles (AuNPs) on enzymatic reaction for blood glucose determination. AuNPs were initially in situ synthesized on the surface of an eggshell membrane (ESM) which was subsequently immobilized with glucose oxidase (GOx) to produce a GOx-AuNPs/ESM. The GOx-AuNPs/ESM was positioned on the surface of an oxygen electrode to form a GOx-AuNPs/ESM glucose biosensor. The effects of pH, concentration of phosphate buffer solution and amount of GOx on the response of the GOx-AuNPs/ESM glucose biosensor were studied in detail. AuNPs on GOx/ESM can improve the calibration sensitivity (30% higher than GOx/ESM without AuNPs), stability (87.3% of its initial response to glucose after 10-week storage) and shortens the response time (<30 s) of the glucose biosensor. The linear working range for the GOx-AuNPs/ESM glucose biosensor is 8.33 μM to 0.966 mM glucose with a detection limit of 3.50 μM (S/N = 3). The biosensor has been successfully applied to determine the glucose in human blood serum samples and the results compared well to a standard spectrophotometric method commonly used in hospitals. Our work demonstrates that the developed GOx-AuNPs/ESM glucose biosensor has potential in biomedical analysis.