9. Extended detection range for an optical enzymatic glucose sensor coupling with a novel data-processing method
A new data-processing method was established and applied for optical enzymatic glucose sensing, in which oxygen and glucose were simultaneously consumed. The oxygen level remaining in the detection system, which was equal to the difference between the initial and consumed oxygen concentrations, could be measured using fluorescent oxygen indicators immobilized in the sensing layer. It was deduced that the ratio of I0 and I was inversely proportional to glucose concentration, where I0 is the maximum fluorescence intensity in various glucose solutions, and I is the fluorescence intensity at various concentrations of glucose. Using the new data-processing method, the detection range of the calibration curve method was extended from 0 to 1.2 mmol L-1, which was enlarged about 2–3 folds over that in ordinary approaches. The prepared glucose sensor could be directly applied to detect high concentrations of glucose.