The development of radio frequency magnetron sputtered p-type nickel oxide thin film field-effect transistor device combined with nucleic acid probe for ultrasensitive label-free HIV-1 gene detection

Sensitive, selective and inexpensive human immunodeficiency virus (HIV) diagnostics are urgently needed for early diagnosis and monitoring of the HIV. We developed a novel label free liquid-ion gated field-effect transistor (FET)-type biosensor for HIV-1 gene detection with the development of p-type semi-conducting nickel oxide (NiO) thin film. Initially, reproducible radio frequency (RF) magnetron sputtering technique was used for deposition of NiO nanoscale thin film on the glass substrate. Electrical measurements showed that NiO certainly provided a high carrier mobility (mu), superior subthreshold swing (SS) and high On/Off ratio in FET device. The pH sensing of NiO-FET device was evaluated and then HIV-1, 5'-amino-modified probe single strand DNA (ssDNA) was covalently immobilized on the surface of the NiO thin film. By integration of the advantages of the NiO and liquid-ion gated FET, an efficient DNA HIV biosensor has been achieved for sensitive detection of target HIV DNA at linear range 1.0 aM to 10.0 nM with a detection limit of 0.3 aM. The proposed biosensor exhibited good selectivity even against non complementary and two-base mismatch sequences and was successfully applied to detect HIV DNA in human serum sample. This device has a promising potential application to monitor other biomarkers in biological fluids and clinical samples. (C) 2018 Elsevier B.V. All rights reserved.