Carbon Nanotube-Based Dual-Gated Junctionless Field-Effect Transistor for Acetylcholine Detection

A compact n-type carbon nanotube (CNT)-based junctionless field-effect transistor (FET) for acetylcholine detection has been fabricated by integrating chitosan/nickel oxide as sensing membrane with CNTFET using chemical solution process. To improve the sensing performances higher than Nernstian, dual-gated junctionless CNTFET has been considered here. Electrical response has been carried out after immobilization of acetylcholine esterase using digital multimeter in presence of phosphate buffer saline of 50 mM and pH 7 in a glass pot. Experimental results show good linearity for acetylcholine concentration from 0.01 to 0.2 mM and improved sensitivity of 1.25 V/decade at room temperature. Limit of detection and Michaelis-Menten constant have been found to be 0.37 μM and 0.2 mM, respectively. Insignificant interference observed while the sensor was tested with other clinical parameters.