Graphene Field Effect Transistor Biosensors Based on Aptamer for Amyloid-<i>β</i>Detection
Mostafa Salehirozveh, Parisa Dehghani, Milan Zimmermann, Vellaisamy A. L. Roy, Hadi Heidari
Abstract
The development of cost-efficient, sensitive and specific methods to detect amyloid-beta 42 (Aβ42) biomarkers in cerebrospinal fluid and serum-samples is of considerable interest to enable early and reliable diagnosis of Alzheimer's disease as a precondition for future disease-modifying therapies. This paper presents a reduced graphene oxide field effect transistor (r-GO FET) for label free ultrasensitive detection of an Aβ42-biomarker with RNA aptamer. The channel in the device was formed by reduction of graphene oxide nanosheets by self-assembly process. As a result, the interaction between Aβ42 and RNA aptamer on the surface of r-GO channel caused a linear response in the shift of the gate voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TG</sub> ) where the minimum conductivity occurs. The r-GO FET can detect the biomarker in range of 1ng/ml to 1pg/ml at pH 7.4 with high specificity. The developed r-GO FET is a low-cost, highly sensitive and selective method for detecting tiny concentrations of Aβ42, which would also enable measurements in serum-samples.