Resonance SERS probe based on the bifunctional molecule IR808 combined with SA test strips for highly sensitive detection of monkeypox virus.

As a zoonotic virus, highly sensitive detection of monkeypox virus is crucial for its prevention and control due to its rapid increase in cases worldwide and the extremely high risk of virus transmission. In this paper, based on the principle of antigen-antibody specific recognition, an ultrasensitive resonance Raman biosensing probe was prepared using a molecule with the bifunctionality of resonance Raman effect and capturing antibody; and with the strong affinity of the biotin-streptavidin (Bio-SA) system, Bio-antibody and SA test strips were prepared. To match the T-line of the test strip, a portable Raman instrument with a strip-shaped spot was designed. Its 0.2 mm spot width ensures full coverage of the T-line and stability of the obtained SERS spectrum of the test strip. Finally, in the pharyngeal swab system, the false positives generated by complex matrix interference were effectively reduced by utilizing the excellent hydrophobicity of S9 surfactant at a concentration of 0.5 %, ultimately achieving a detection limit of 1 pg/mL and taking less than 15 min. Experimental data shows that the SERS performance of SERRS probes is at least 2 orders of magnitude better than that of other highly sensitive molecular probes. Based on the use of bifunctional molecules and the affinity of the BiO-SA system, this approach ensures the strength of SERS signals, more efficient antibody loading, and the ability of the test strip to capture probes, and the effectiveness of surfactant S9% in suppressing false positives in throat swab systems was verified. The experiment proved that the scheme had certain reference value for the high-sensitivity POCT rapid detection of monkeypox virus based on SERS technology.