Open AccessBeyond the Debye length in high ionic strength solution: direct protein detection with field-effect transistors (FETs) in human serum
Author(s) -
ChiaChi Chu,
Indu Sarangadharan,
Abiral Regmi,
Yen Wen Chen,
Cheng-Wei Hsu,
Wen Hsin Chang,
Geng Yen Lee,
JenInn Chyi,
Chih Chen Chen,
Shu Chu Shiesh,
GwoBin Lee,
Yu Lin Wang
Publication year - 2017
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/s41598-017-05426-6
Subject(s) - ionic strength , transistor , biosensor , materials science , debye length , field effect transistor , optoelectronics , sensitivity (control systems) , aptamer , point of care , dilution , ionic bonding , nanotechnology , computer science , chemistry , electronic engineering , electrical engineering , ion , medicine , biology , physics , microbiology and biotechnology , engineering , nursing , organic chemistry , voltage , aqueous solution , thermodynamics
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.