Aptamer-Based Electric-Double -Layer (EDL) Extended-Gated FET Biosensor for Detection of Cadmium Ion

Abstract

In this study, we developed an electric double-layer (EDL) extended-gate field effect transistor sensor based on aptamers to detect cadmium ions (Cd2+). Since the aptamer has a specific binding ability to cadmium ions. The signal is amplified through the transconductance of the FET. The linear detection range of this sensor for cadmium ions is from 1 nM to 10 uM. The Cd2+ calibration curve is shown a high correlation coefficient (R2 = 0.981) and an excellent detection limit as low as 0.094 nM. Importantly, it responds to Cd2+ within 10 seconds. The sensor exhibits high selectivity in the presence of other heavy metals. It also can be reused without significant signal attenuation. The advantages of this method are convenient portability, short detection time, high sensitivity, and simple operation. It has a good prospect for detection in the daily life of cadmium environmental pollution.