A multi-frequency system for glucose detection with optical sensors

The aim of this work is to perform preliminaries studies to evaluate an optical sensor system for glucose detection in solution, in order to provide suitable indications to develop a device for non invasive glycaemia continuous monitoring. In this study an experimental set-up consisting of a LED-Photodiode couple has been tested as glucose sensor. LED´s emission is partially absorbed by the glucose solution and photodiode output voltage correlates with the concentration of glucose in solution. The glucose water solution, placed into cuvettes suitable for spectrophotometric analysis, ranged from a glucose concentrations of 75 mg/dl up to 3000 mg/dl. Three different wavelengths were investigated: 740 nm, 880 nm and 1550 nm. The best performances in terms of sensitivity and resolutions were obtained at 1550 nm. A PLS-DA analysis was performed in order to enhance the global resolution of the system.