Rapid, Sensitive, and Reusable Detection of Glucose by a Robust Radiofrequency Integrated Passive Device Biosensor Chip

Tremendous demands for sensitive and reliable label-free biosensors have stimulated intensive research into developing miniaturized radiofrequency resonators for a wide range of biomedical applications. Here, we report the development of a robust, reusable radiofrequency resonator based integrated passive device biosensor chip fabricated on a gallium arsenide substrate for the detection of glucose in water-glucose solutions and sera. As a result of the highly concentrated electromagnetic energy between the two divisions of an intertwined spiral inductor coupled with an interdigital capacitor, the proposed glucose biosensor chip exhibits linear detection ranges with high sensitivity at center frequency. This biosensor, which has a sensitivity of up to 199 MHz/mgmL(-1) and a short response time of less than 2 sec, exhibited an ultralow detection limit of 0.033 mu M and a reproducibility of 0.61% relative standard deviation. In addition, the quantities derived from the measured S-parameters, such as the propagation constant (gamma), impedance (Z), resistance (R), inductance (L), conductance (G) and capacitance (C), enabled the effective multi-dimensional detection of glucose.