Development of a highly-sensitive acetylcholine sensor using a charge-transfer technique on a smart biochip

Abstract

We have developed a highly-sensitive acetylcholine (ACh) sensor based on a charge-transfer technique (CTT) using a smart biochip. The CCT ACh sensor (CTTAS) involves a charge-accumulation technique for detecting choline and H+ ions, the sensing signals being amplified without an external amplifier. The CTTAS exhibits excellent performance for ACh detection with high sensitivity (11.6 mV/mM), high signal-to-noise ratio, large span (537 mV), wide linear range (1.5∼12.5 mM), fast response time (<20 s) and very good reproducibility. We obtained a very low limit of detection (∼0.01 mM). Under optimal conditions, the CTTAS outstripped the performance of the widely-used enzyme field-effect transistor (ENFET) with sensitivity more than three times greater than that of the ENFET (3.6 mV/mM). The CTTAS exhibited good selectivity, sensitivity, reproducibility and stability over a large concentration range. Due to its high resolution, fast response, small size and low cost, the CTTAS has tremendous potential for applications in medical research and clinical diagnosis. © 2008 Elsevier Ltd. All rights reserved.