Abstract
The authors demonstrate a small molecule 17 beta-estradiol (E2) sensor based on aptamer functionalized carbon nanotube network film field effect transistors (CNT FETs). The real time current response for the 35-mer E2 aptamer functionalized CNT FET shows a clear increase in current over the range of 50nM to 1.6 mu M of E2. The E2 response using a longer 75-mer version of the aptamer functionalized CNT FETs, where the aptamer/E2 binding occurs beyond the Debye length, shows no obvious evidence of sensing. The CNT FET sensing platform has been fabricated via a simple surfactant free solution processing route, compatible with further carbon nanotube functionalization to develop a versatile sensing platform. The CNT FET aptasensors are able to perform real time monitoring of E2 levels for selective and quantitative detection of E2 in liquids. (C) 2015 American Vacuum Society.