High-performance cholesterol sensor based on the solution-gated field effect transistor fabricated with ZnO nanorods.

A high-performance cholesterol sensor based on solution-gated field-effect-transistor (FET) was fabricated by using the vertically aligned ZnO nanorods (ZnO NRs) grown selectively on pre-patterned substrate in solution. The structural characterization showed that the as-grown ZnO NRs are vertically aligned, high purity single crystalline. The active layer of ZnO NRs between source and drain electrodes was immobilized with cholesterol oxidase (ChOx) enzyme. The performance of the fabricated FET sensor has been examined with the cholesterol solutions with and without electroactive species, the human serum (H4522), and the freshly drawn blood sample. The FET sensor provided a real-time response towards a wide range of cholesterol concentration (0.001-45 mM) with high sensitivity (10 μA cm(-2) mM(-1)) and selectivity.