Abstract
Background and aim:
At the end of 2019, the Coronavirus appeared and spread very promptly, causing millions of infections and deaths around the world, and turning into a global pandemic. For this reason, it has become necessary to find appropriate tests for an accurate and rapid diagnosis of this disease. In fact, the biosensor was the most efficient technique to detect, with high sensibility and accuracy, the SARS-CoV-2 virus. Through this study we try to improve the accuracy of the applied alternating current electrothermal (ACET) force on the immunoassay reaction during the controlled-temperature process.
Methods:
A two-dimensional numerical simulation implementing proportional-integral-derivative (PID) control algorithm using the Finite Element Method was carried out to control heat rise and to keep the target tip temperature below the preset temperature value during the immunoassay reaction.
Results:
The effect of analyte concentration, the inlet velocity, and the effect of ACET on the SARS-COV-2 binding reaction has been investigated. The present results show that the biosensor response is highly influenced by the temperature rise. An optimal operating voltage of Vmax = 10.29 V was identified, corresponding to a maximum allowable temperature rise of ΔT < 5 K, ensuring efficient binding while maintaining thermal stability
Conclusion:
Optimizing the utility of ACET in medical laboratories will provide an important path toward design parameters that can significantly improve biosensor performance and enable safe and risk-free use.

Key words: Heterogeneous immunoassays; COVID-19; SARS-CoV-2; Biosensors; AC electrothermal effects; Detection time; Controlled temperature