A portable miniaturized PB2+ detector using ion-responsive hydrogel with wireless interrogation capability

摘要

This paper presents a passive wireless Pb2+ sensor by employing ion-responsive hydrogel with an inductor capacitor (L-C) resonator. When water passes through the device flowing into a hydrogel cavity, the hydrogel in the cavity swells and changes the capacitance of the integrated L-C resonator, which in turn changes the resonant frequency that can be remotely detected by using the phase-dip technique. The measured results show the proposed device gives 4.5% shifting of resonant frequency for a water sample with Pb2+concentration 10-10 M, which is about two orders of magnitude smaller than the Pb2+ concentration harmful to human, which indicates the effectiveness of the proposed device.