Beyond the Debye length in high ionic strength solution: direct protein detection with field-effect transistors (FETs) in human serum

Abstract In this study, a new type of field-effect transistor (FET)-based biosensor is demonstrated to be able to overcome the problem of severe charge-screening effect caused by high ionic strength in solution and detect proteins in physiological environment. Antibody or aptamer-immobilized AlGaN/G...

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Bibliographic Details
Main Authors: Chia-Ho Chu, Indu Sarangadharan, Abiral Regmi, Yen-Wen Chen, Chen-Pin Hsu, Wen-Hsin Chang, Geng-Yen Lee, Jen-Inn Chyi, Chih-Chen Chen, Shu-Chu Shiesh, Gwo-Bin Lee, Yu-Lin Wang
Format: Article
Language:English
Published: Nature Publishing Group 2017-07-01
Series:Scientific Reports
Online Access:https://doi.org/10.1038/s41598-017-05426-6
Description
Summary:Abstract In this study, a new type of field-effect transistor (FET)-based biosensor is demonstrated to be able to overcome the problem of severe charge-screening effect caused by high ionic strength in solution and detect proteins in physiological environment. Antibody or aptamer-immobilized AlGaN/GaN high electron mobility transistors (HEMTs) are used to directly detect proteins, including HIV-1 RT, CEA, NT-proBNP and CRP, in 1X PBS (with 1%BSA) or human sera. The samples do not need any dilution or washing process to reduce the ionic strength. The sensor shows high sensitivity and the detection takes only 5 minutes. The designs of the sensor, the methodology of the measurement, and the working mechanism of the sensor are discussed and investigated. A theoretical model is proposed based on the finding of the experiments. This sensor is promising for point-of-care, home healthcare, and mobile diagnostic device.
ISSN:2045-2322