Enhanced Sensitivity Using Microfluidic, Interdigitated Microelectrode Based Capacitance Glucose Sensor Measured at 4 MHz

This paper successfully demonstrates that a sensing device, with a microfluidic channel, integrated with interdigitated microelectrode (ID mu E), is able to detect different glucose concentrations without immobilizing enzymes onto the surface of microelectrodes. Phosphate buffered saline (PBS) solution (10X) was used as a sensing medium and the measurement frequency determines the device sensitivity. Higher measurement frequency enhances sensitivity. A model of an equivalent circuit is proposed and a theoretical simulation and calculation are fitted with the experimental data. The principle of measurement is based on changes in the dielectric constant of the analyte dissolved in the buffer solution at different concentrations. Thus, an increased sensitivity is obtained at a higher measurement frequency (4 MHz). The sensing device demonstrated here has potential for application to disposable polymer lab-on-a-chips for biochemical analysis and clinical diagnostics. (C) 2014 The Electrochemical Society. All rights reserved.