Rapid COVID-19 diagnosis using a versatile and cost-effective plasmonic biosensor

What is it about?

The most extensively used approach for identifying the COVID-19-causing SARS-CoV-2 virus in patient samples is reverse transcription polymerase chain reaction (RT-PCR) analysis. It is, however, time-consuming and prone to cross-contamination, increasing the chances of incorrect test interpretation. This necessitates more reliable and quick diagnostic procedures that can ex-amine many samples with high accuracy. This article provides an effective and rapid method for detecting SARS-CoV-2 based on a combination of two phenomena. First, the localized surface plasmon resonance (LSPR) used for sensing, and second, the plasmonic photothermal (PPT) effect that generates heat energy when light hits the nanoparticles. The synthesized gold-nanoisland (AuNIs) chips were coated with receptors containing COVID-19 complementary DNA sequences. On sample addition, these receptors allowed the binding of any incoming COVID-19 genetic material that contained complementary sequences. The biosensor was highly specific in detecting the presence of SARS-CoV-2 by plasmonic sensing. Interestingly, when the chips were exposed to a high-power laser, the binding and specificity of the detection increased further owing to the PPT effect.

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Photo by Irwan iwe on Unsplash

Photo by Irwan iwe on Unsplash

Why is it important?

The LSPR and PPT phenomena together ensure the success of this 'dual-function plasmonic biosensor,' which may be used as a reliable and cost-effective COVID-19 diagnostic tool. Given the enhanced sensing stability and sensitivity of the system, distinguishing SARS-CoV-2 from other viruses may now be considerably easier with its use. The use of PPT for enhancing COVID-19 detection is yet another break-through which might lead to better viral diagnosis in the future. Infusing both plasmonic and photothermal properties in the biosensor improved the overall binding of viral DNA to the strip, which was confirmed using multiple SARS-CoV-2 sequences. KEY TAKEAWAY: The proposed dual-functional LSPR biosensor allows for quick and accurate COVID-19 diagnosis. It can improve the credibility of sample testing and reporting while also reducing the load on RT-PCR-based assays.