Design and fabrication of an optical sensor for glucose measurement in a microfluidic chip

This paper describes the design and fabrication of an optical glucose sensing system in a microfluidic chip on a PDMS substrate. We studied the potential of the near infrared wavelength, 940 nm as glucose sensor based on Beer lambert's law. This sensor consists of a 940nm IR-LED as a light source and a PIN photodiode that is sensitive to that wavelength. The detection of glucose was performed by aqueous glucose solutions in the clinical concentration range in a PDMS-based microfluidic chip. The relationship between system output voltage and glucose concentration was studied in transmission spectroscopy. For glucose solutions ranging from 60 to 300 mg/dL the output voltages were approximately changed linearly from 1211 to 1129 mv. Based on the promising results obtained from the experiments, this sensor has the potential for glucose detection in complex physiological environments.