Prediction of Glucose Concentration in a Glucose-Lactose Mixture Based on the Reflective Optical Power at Dual Probe Wavelengths

Department of Electronic Engineering, Kwangwoon University, 20 Kwangwoon-ro, Nowon-gu, Seoul 01897, South Korea(Received September 17, 2015 : revised November 11, 2015 : accepted December 8, 2015)An enzyme-free optical method is proposed for estimating high concentrations of glucose in a glucose-lactose mixture, based on a predictive equation that takes advantage of the reflective optical power observed at two discrete wavelengths. Compared to the conventional absorption spectroscopy method based on Beer’s Law, which is mainly valid for concentrations below hundreds of mg/dL, the proposed scheme, which relies on reflection signals, can be applied to measure higher glucose concentrations, of even several g/dL in a glucose-lactose mixture. Two probe wavelengths of 1160 and 1300 nm were selected to provide a linear relationship between the reflective power and pure glucose/lactose concentration, where the relevant linear coefficients were derived to complete the predictive equation. Glucose concentrations from 2 to 7 g/dL in a glucose-lactose mixture were efficiently estimated, using the established predictive equation based on monitored reflective powers. The standard error of prediction was 1.17 g/dL.Keywords : High glucose concentration, Correlation coefficient, Glucose-lactose mixture, Reflective optical powerOCIS codes : (280.4788) Optical sensing and sensors; (120.5700) Reflection; (330.1880) Detection; (350.4800) Optical standards and testing