Bisphenol A Detection Using Molybdenum Disulfide (MoS₂) Field‐Effect Transistor Functionalized with DNA Aptamers

Abstract

Bisphenol A exposure, even at very low concentrations, is associated with an increased risk of high blood pressure, heart disease, diabetes and some cancers. It is important to monitor BPA exposure level for human healthcare. Two‐dimensional materials‐based field‐effect transistors are promising for sensing applications due to their high sensitivity, label‐free detection, and reusability. Among 2D materials MoS2 based semiconductor materials provides higher sensitivity compared to the lack of sensitive existing graphene materials due to bandgap. In this work, a microfluidic device based on MoS2 field‐effect transistor is demonstrated that can be adapted to detect several biomolecules at very low concentrations. MoS2 channel is functionalized by depositing gold nanoparticles and immobilizing single one (or double)‐stranded DNA. It is found that dsDNA functionalized devices exhibit higher sensitivity compared to ssDNA for all BPA concentrations due to p‐doing effect of dsDNA on MoS2 semiconducting surface. Both ss and dsDNA functionalized MoS2 FET devices are able to detect BPA concentration as low as 1 pg mL−1, as observed by a 4.27% and 2.17% change in the current, respectively, and a response time of about ≈4 s. The demonstrated MoS2 FET sensors are very promising to detect lower concentration biomolecules and DNA in biomedical applications.