TY - JOUR
AU - Roychoudhury, Appan
AU - Allen, Richard James
AU - Curt, Tine
AU - Farrell, James
AU - McAllister, Gina E.M.
AU - Templeton, Kate
AU - Bachmann, Till T
PY - 2022
DA - December
TI - Amplification Free Detection of SARS-CoV-2 Using Multi-valent Binding
JO - ACS Sensors
DO - https://doi.org/10.1021/acssensors.2c01340
AB - We present the development of electrochemical impedance spectroscopy (EIS)-based biosensors for sensitive detection of SARS-CoV-2 RNA using multi-valent binding. By increasing the number of probe–target binding events per target molecule, multi-valent binding is a viable strategy for improving the biosensor performance. As EIS can provide sensitive and label-free measurements of nucleic acid targets during probe–target hybridization, we used multi-valent binding to build EIS biosensors for targeting SARS-CoV-2 RNA. For developing the biosensor, we explored two different approaches including probe combinations that individually bind in a single-valent fashion and the probes that bind in a multi-valent manner on their own. While we found excellent biosensor performance using probe combinations, we also discovered unexpected signal suppression. We explained the signal suppression theoretically using inter- and intra-probe hybridizations which confirmed our experimental findings. With our best probe combination, we achieved a LOD of 182 copies/μL (303 aM) of SARS-CoV-2 RNA and used these for successful evaluation of patient samples for COVID-19 diagnostics. We were also able to show the concept of multi-valent binding with shorter probes in the second approach. Here, a 13-nt-long probe has shown the best performance during SARS-CoV-2 RNA binding. Therefore, multi-valent binding approaches using EIS have high utility for direct detection of nucleic acid targets and for point-of-care diagnostics.
PB - ACS Publications
UR - https://www.research.ed.ac.uk/en/publications/bd92224e-276d-4481-b8c4-007389df05d5
KW - Coronavirus (COVID-19)
ER