SARS-CoV-2 detection with aptamer-functionalized gold nanoparticles

A rapid detection test for SARS-CoV-2 is urgently required to monitor virus spread and containment. Here, we describe a test that uses nanoprobes, which are gold nanoparticles functionalized with an aptamer specific to the spike membrane protein of SARS-CoV-2. An enzyme-linked immunosorbent assay confirms aptamer binding with the spike protein on gold surfaces. Protein recognition occurs by adding a coagulant, where nanoprobes with no bound protein agglomerate while those with sufficient bound protein do not. Using plasmon absorbance spectra, the nanoprobes detect 16 nM and higher concentrations of spike protein in phosphate-buffered saline. The timevarying light absorbance is examined at 540 nm to determine the critical coagulant concentration required to agglomerates the nanoprobes, which depends on the protein concentration. This approach detects 3540 genome copies/mu l of inactivated SARS-CoV-2.

Automated summary

The study introduces a rapid detection test for SARS-CoV-2 utilizing nanoprobes functionalized with specific aptamer to identify spike membrane protein. The nanoprobes successfully detect spike protein concentrations of 16 nM and higher.