Piezoelectric point-of-care biosensor for the detection of SARS-COV-2 (COVID-19) antibodies.

It is always challenging to diagnose a disease using a biosensor reliably, and quickly with high sensitivity and selectivity, simultaneosuly. Recently the world experienced a global pandemic caused by a novel coronavirus (COVID-19). Although the vaccines are available, COVID-19 resulted a huge threat to the entire world with high mortality rates. Irrespective of a specific disease, there is a constant need for a cheaper and faster in-vitro, lab-on-a-chip sensor with high sensitivity and selectivity. Such sensors will not only facilitate the disease detection but will expedite and vaccine development process through detection of its corresponding antibodies when developed. In this article, we present an ultrasonic guided wave sensor using 128° YX lithium niobate piezoelectric wafer, specially designed in a shape of a multi-threaded comb with cantilever beams which is equally selective and sensitive for the detection of corresponding antigen-antibody assays. As a proof of concept in this article, the diagnostic sensor is created and tested for detection of SARS-COV-2 antibodies. Sensors were functionalized with SARS-COV-2 antigens and target antibody for the same was detected. Unique and judicially tuned acoustic features are analyzed for successful detection of the right antibodies. The proposed lab-on-a-chip device utilizes a wide range of diagnostic frequencies resulting into a highly sensitive platform for the diagnostics even to the slightest biophysical changes. The proposed sensor is also believed to extend to the detection of various other antigens/antibodies of different diseases in the future.