An Amplification Strategy to Label Free Opiate Drug Detection using Liquid-Gated Carbon Nanotubes Transistor

摘要

The proliferation of narcotic analgesic drug, heroin, has necessitated the development for on-site drug diagnosis. Carbon nanotubes (CNTs), which are renowned for its good biocompatibility and excellent electrical sensitivity, has been an area of active research in the past decade for its applications in biosensing. In this paper, a CNT based field effect transistor (CNTFET) was employed for the direct electrical detection of 6-monoacetylmoprhine. An indirect detection scheme was adopted to enable the detection of morphine antibodies. By incorporating gold nanoparticles to the morphine antibodies, an improvement of the detection limit by two orders of magnitude from 130 fg/ml to ～1 fg/ml was achieved. The mechanism of signal enhancement effect was attributed to the electrostatic gating contribution from the negatively charged gold nanoparticle in addition to the antibodies themselves.