Wang, R.; Zhu, B.; Young, P.; Luo, Y.; Taylor, J.; Cameron, A.J.; Squire, C.J.; Travas-Sejdic, J. A Portable and Disposable Electrochemical Sensor Utilizing Laser-Scribed Graphene for Rapid SARS-CoV-2 Detection. Biosensors2024, 14, 10.
Wang, R.; Zhu, B.; Young, P.; Luo, Y.; Taylor, J.; Cameron, A.J.; Squire, C.J.; Travas-Sejdic, J. A Portable and Disposable Electrochemical Sensor Utilizing Laser-Scribed Graphene for Rapid SARS-CoV-2 Detection. Biosensors 2024, 14, 10.
Wang, R.; Zhu, B.; Young, P.; Luo, Y.; Taylor, J.; Cameron, A.J.; Squire, C.J.; Travas-Sejdic, J. A Portable and Disposable Electrochemical Sensor Utilizing Laser-Scribed Graphene for Rapid SARS-CoV-2 Detection. Biosensors2024, 14, 10.
Wang, R.; Zhu, B.; Young, P.; Luo, Y.; Taylor, J.; Cameron, A.J.; Squire, C.J.; Travas-Sejdic, J. A Portable and Disposable Electrochemical Sensor Utilizing Laser-Scribed Graphene for Rapid SARS-CoV-2 Detection. Biosensors 2024, 14, 10.
Abstract
The COVID-19 pandemic caused by the virus SARS-CoV-2 has been the greatest global threat to human health in the last three years. The most widely used methodologies for the diagnosis of COVID-19 are quantitative reverse transcription polymerase chain reaction (RT-qPCR), used to detect the viral genome, and rapid antigen tests (RATs), also known as lateral flow tests, that employ specific antibodies to detect the viral spike protein. While PCR is considered the gold standard test in terms of specificity and sensitivity, it is time-consuming and requires specialized instrumentation operated by skilled personnel. In contrast, RATs can be used in-home or at point-of care but are less sensitive leading to a higher rate of false negative results. An alternative methodology for the detection of virus is the use of electrochemical biosensors that employ disposable strip electrodes to which binding of viral components elicits a change in electrical signal. Laser-scribed graphene (LSG) electrodes are attractive candidates for use as biosensors electrodes suitable for SARS-COV-2 detection due to their low-cost, patternability and ease of fabrication. In this work, we describe the development of a biosensor for COVID-19 detection that exploits a split-ester bond ligase system (termed ‘EsterLigase’) for immobilization of a virus-specific nanobody to maintain the out-of-plane orientation of the probe to ensure the efficacy of the probe-target recognition process. An anti-spike VHH E nanobody, genetically fused with the EsterLigase domain, was used as the specific probe for the spike receptor-binding domain (SP-RBD) protein as the target. The recognition between the two was measured by the change in the charge transfer resistance, determined by fitting the electrochemical impedance spectroscopy (EIS) spectra. The developed LSG-based biosensor achieved a linear detection range for the SP-RBD from 15 pM to 150 nM with a sensitivity of 0.0866 [log(M)]-1 and a limit of detection (LOD) of 7.68 pM.
Chemistry and Materials Science, Materials Science and Technology
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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