Zika virus detection using antibody-immobilized disposable cover glass and AIGaN/GaN high electron mobility transistors

Zika virus detection was demonstrated using antibody-functionalized cover glasses externally connected to the gate electrode of an AIGaN/GaN high electron mobility transistor (HEMT). A pulsed bias voltage of 0.5 V was applied to an electrode on the region of the cover glass region functionalized with antibody, and the resulting changes of drain current of the HEMT were employed to determine the presence of Zika virus antigen concentration ranging from 0.1 to 100 ng/ml. The dynamic and static drain current changes as a function of Zika virus concentration were modeled with a spring-like elastic relaxation model and the Langmuir extension model, respectively. Excellent fits to the data were found with relaxation time constants of antibody and antigen molecules in the range of 11 mu s and 0.66-24.4 mu s, respectively, for the concentration range investigated. The ratio of antibody bound with antigen to the total available antibody on the functionalized contact window was in the range of 0.013-0.84 for the Zika antigen concentration range of 0.1-100 ng/ml. Since the HEMT is not exposed to the bio-solution, it can be used repeatedly. The functionalized glass is the only disposable part in the detection system, showing the potential of this approach for hand-held, low cost sensor packages for point-of-care applications. Published by AIP Publishing.