A highly sensitive glucose biosensor based on a microstrip ring resonator

This paper presents a highly sensitive biosensor based on a microstrip ring resonator to detect glucose concentration. The proposed sensor structure allows observation of small variation of glucose concentration by two port S-parameter measurement. The sensor is based on a resonant microstrip ring with a microfluidic container placed on top. The interaction between the electric field and the milliliter range water-glucose solutions under test can be observed measuring the phase shift of the S-parameter from 3.98 to 4.05 GHz. Combining the microwave detection and the microfluidic network, a time efficient and low cost architecture is presented. With this technique a very sensitive water-glucose concentration of less than 50 mg/dl can be separated.