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Rapid and sensitive SARS-CoV-2 detection using a homogeneous fluorescent immunosensor Quenchbody with crowding agents
Bo Zhu1, Nobuyuki Nosaka2, Shuji Kanamaru3
1Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan. ueda@res.titech.ac.jp.
The Analyst
|October 7, 2022
Summary
This study developed a rapid SARS-CoV-2 antigen test using Quenchbody technology. Adding polyethylene glycol improved sensitivity and speed for detecting the N protein, enabling efficient COVID-19 diagnosis.
Area of Science:
- Biomedical Engineering
- Immunotechnology
- Infectious Disease Diagnostics
Background:
- Homogeneous immunosensors are crucial for widespread SARS-CoV-2 antigen testing.
- Existing methods face challenges in speed and sensitivity for large-scale monitoring.
Purpose of the Study:
- To develop a high-performance homogeneous immunosensor for SARS-CoV-2 nucleocapsid (N) protein detection.
- To investigate the role of crowding agents in enhancing Quenchbody immunosensor performance.
Main Methods:
- Utilized PM Q-probe and Quenchbody technologies with an anti-N protein antibody.
- Incorporated polyethylene glycol 6000 as a crowding agent to optimize the assay.
- Validated the immunosensor using clinical specimens and a compact tube fluorometer.
Main Results:
- Achieved a limit of detection of 191 pM for recombinant N protein within 15 minutes.
- Demonstrated a 9- to 10-fold improvement in sensitivity compared to assays without crowding agents.
- Successfully validated the immunosensor in point-of-care testing with COVID-19 patient samples.
Conclusions:
- The developed Quenchbody homogeneous immunosensor offers rapid and cost-efficient detection of SARS-CoV-2.
- Crowding agents significantly enhance the sensitivity and response speed of the assay.
- This technology is feasible for large-scale monitoring and epidemiological studies of infectious diseases.
