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Stable Organic Field-Effect Transistors for Continuous and Nondestructive Sensing of Chemical and Biologically Relevant Molecules in Aqueous Environment
journal contribution
posted on 2014-02-12, 00:00 authored by Minseong Yun, Asha Sharma, Canek Fuentes-Hernandez, Do Kyung Hwang, Amir Dindar, Sanjeev Singh, Sangmoo Choi, Bernard KippelenThe use of organic field-effect transistors
(OFETs) as sensors in aqueous media has gained increased attention
for environmental monitoring and medical diagnostics. However, stable
operation of OFETs in aqueous media is particularly challenging because
of electrolytic hydrolysis of water, high ionic conduction through
the analyte, and irreversible damage of organic semiconductors when
exposed to water. To date, OFET sensors have shown the capability
of label-free sensing of various chemical/biological species, but
they could only be used once because their operational stability and
lifetime while operating in aqueous environments has been poor, and
their response times typically slow. Here, we report on OFETs with
unprecedented water stability. These OFETs are suitable for the implementation
of reusable chemical/biological sensors because they primarily respond
to charged species diluted in an aqueous media by rapidly shifting
their threshold voltage. These OFET sensors present stable current
baselines and saturated signals which are ideal for detection of low
concentration of small or large molecules that alter the pH of an
aqueous environment. The overall response of these OFET sensors paves
the way for the development of continuous chemical/biological nondestructive
sensor applications in aqueous media.