A high sensitivity microwave glucose sensor

Abstract

A simple, sensitive, low-cost microwave sensor capable of conducting glucose concentration measurements has been developed without chemical bindings. The sensing device uses a microstrip transmission line to detect variation of the glucose component of the solutions placed in a cavity under it. The uniform and concentrated electric field distribution results in an accurate and sensitive measurement of the absorption frequency shift in the frequency response of the sensor. The sensor was fabricated on a FR4 substrate for low-cost purpose. The shift in the absorption frequency of the device was measured in the frequency range between 4.8 GHz and 5.7 GHz using solutions with different glucose concentrations in two ranges: (a) high concentration from 1000 mg dl−1 to 8000 mg dl−1 and (b) low concentration from 100 mg dl−1 to 300 mg dl−1. The experimental results showed a high sensitivity of 0.32 MHz (mg dl−1)−1 for the low concentrations in terms of absorption frequency.