Glucose Monitoring by a Biosensor Based on Mercury Thin Film Electrodes

Abstract

Mercury film electrodes consist of a thin film of mercury deposited on an electrode surface (typically glassy carbon) by reduction of a mercury (II) salt in solution. The surface area/volume ratio is larger for the mercury film electrode, and this electrode is more stable than mercury drop electrode, which allows a faster stirring rate to be used in the deposition step. An enzyme electrode is described, based on glucose oxidase immobilized by gelatin and glutaraldehyde and held over a glassy carbon electrode coated with a thin mercury film. This biosensor responds fast and linearly to glucose in a wide concentration range, which is significant because monitoring of glucose levels is a critical component of diabetes care. Certain optimization and characterization studies were carried out. Average value, standard deviation (SD), and variation coefficient (CV) were calculated with the help of the repeatability studies. Finally, glucose content of human blood samples was monitored with the help of the biosensor presented.

Keywords:

• Biosensor
• Clark electrode
• Glucose
• Glucose oxidase
• Mercury thin film

Notes

∗The samples were taken before meals.

∗∗Mean of three determinations.