DNA based chemical sensor for the detection of nitrogen dioxide enabled by organic field-effect transistor

Abstract

DNA based chemical sensor for the detection of nitrogen dioxide (NO2) enabled by organic field-effect transistor (OFET) was fabricated. In this OFET-based chemical sensor, DNA was introduced between the gate dielectric and the organic semiconducting layer via spray-coating to function as the detecting layer for NO2 analyte. Comparing with the OFET without the DNA interlayer, an enhanced sensing performance of OFET with the DNA interlayer was observed when exposed to various concentrations of NO2 analyte. The sensitivity of the OFET-based sensor with DNA interlayer was nearly one order of magnitude higher than that of the controlled device. The results showed that there were the remarkable shifts of saturation current and charge carrier mobility after exposed to NO2 analyte. By analyzing the electrical characteristics, and the morphologies of the dielectrics and pentacene films of the OFET-based sensors, the performance enhancement was ascribed to the negatively charged phosphate groups in DNA molecules, which could interact with NO2 analytes and lead to a superior sensing performance of OFET incorporating with DNA.