A Cell-Based Electrochemical Biosensor for the Detection of Infectious Hepatitis A Virus

Hepatitis A virus (HAV), a major cause of acute liver infections, is transmitted through the fecal-oral route and close contact with infected individuals. Current HAV standardized methods rely on the detection of virus antigen or RNA, which do not differentiate between infectious and non-infectious HAV. The objective of this study was to develop a prototype cell-based electrochemical biosensor for detection of infectious HAV. A cell culture-adapted HAV strain (HM175/18f) and its permissive cells (FRhK-4), along with gold nanoparticle-modified screen-printed electrodes, were used to develop the biosensor. Electrochemical impedance spectroscopy was used to quantify the electrical impedance signal. Nyquist plots showed successful fabrication of the cell-based biosensor. The optimum period of HAV incubation with the biosensor was 6 h. A significant linear relationship (R² = 0.98) was found between the signal and a 6-log range of HAV titers, with a limit of detection of ~5 TCID₅₀/mL (tissue culture infectious dose). The biosensor did not detect non-target viruses such as feline calicivirus and human coronavirus 229E. The biosensor was stable for 3 to 7 days at an abusive temperature (37 °C), retaining ~90 to 60% of the original signal, respectively. In conclusion, this prototype cell-based biosensor is capable of rapidly detecting low levels of infectious HAV.