Nanotechnology-Assisted Biosensors for the Detection of Viral Nucleic Acids: An Overview.

The accurate and rapid diagnosis of viral diseases has garnered increasing attention in the field of biosensors. The development of highly sensitive, selective, and accessible biosensors is crucial for early disease detection and preventing mortality. However, developing biosensors optimized for viral disease diagnosis has several limitations, including the accurate detection of mutations. For decades, nanotechnology has been applied in numerous biological fields such as biosensors, bioelectronics, and regenerative medicine. Nanotechnology offers a promising strategy to address the current limitations of conventional viral nucleic acid-based biosensors. The implementation of nanotechnologies, such as functional nanomaterials, nanoplatform-fabrication techniques, and surface nanoengineering, to biosensors has not only improved the performance of biosensors but has also expanded the range of sensing targets. Therefore, a deep understanding of the combination of nanotechnologies and biosensors is required to prepare for sanitary emergencies such as the recent COVID-19 pandemic. In this review, we provide interdisciplinary information on nanotechnology-assisted biosensors. First, representative nanotechnologies for biosensors are discussed, after which this review summarizes various nanotechnology-assisted viral nucleic acid biosensors. Therefore, we expect that this review will provide a valuable basis for the development of novel viral nucleic acid biosensors.

Effectiveness of Disinfectants Suitable for Inactivating SARS-CoV-2 at Cold-Chain Temperature.

To prevent the spread of SARS-CoV-2 in cold-chain transportation in China, we developed specific cryogenic disinfectants. Carrier tests were performed against SARS-CoV-2 at - 20 °C for the four cryogenic disinfectants developed and qRT-PCR was used to test the virus RNA. Peracetic acid, chlorine disinfectants (two different concentrations), and quaternary ammonium disinfectant with their antifreeze can all inactivate SARS-CoV-2 in 5 min at - 20 °C. However, after 2-3 h of exposure, only chlorine disinfectant could destroy SARS-CoV-2 RNA. The viruses treated with peracetic acid and quaternary disinfectants showed positive Ct values even after 3 h detected with qRT-PCR. The conclusion was that the cold-chain disinfectants we tested could inactivate SARS-CoV-2 quickly and effectively, but only chlorine disinfectants could destroy nucleic acids in 3 h. Our study also illustrated that using qRT-PCR detection of viral nucleic acids to assess disinfection was inappropriate.