Immunoassay platform with surface-enhanced resonance Raman scattering for detecting trace levels of SARS-CoV-2 spike protein.
BISTAFFA, Maria J.; CAMACHO, Sabrina Alessio; PAZIN, Wallance Moreira; CONSTANTINO, Carlos J. L.; OLIVEIRA JUNIOR, Osvaldo Novais de; AOKI, Pedro Henrique Benites.
BISTAFFA, Maria J.; CAMACHO, Sabrina Alessio; PAZIN, Wallance Moreira; CONSTANTINO, Carlos J. L.; OLIVEIRA JUNIOR, Osvaldo Novais de; AOKI, Pedro Henrique Benites.
Abstract: The early diagnosis of Coronavirus disease (COVID-19) requires either an accurate detection of genetic material or a sensitive detection of viral proteins. In this work, we designed an immunoassay platform for detecting trace levels of SARS-CoV-2 spike (S) protein. It is based on surface-enhanced resonance Raman scattering (SERRS) of methylene blue (MB) adsorbed onto spherical gold nanoparticles (AuNPs) and coated with a 6 nm silica shell. The latter shell in the SERRS nanoprobe prevented aggregation and permitted functionalization with SARS-CoV-2 antibodies. Specificity of the immunoassay was achieved by combining this functionalization with antibody immobilization on the cover slides that served as the platform support. Different concentrations of SARS-CoV-2 antigen could be distinguished and the lack of influence of interferents was confirmed by treating SERRS data with the multidimensional projection technique Sammon?s mapping. With SERRS using a laser line at 633 nm, the lowest concentration of spike protein detected was 10 pg/mL, achieving a limit of detection (LOD) of 0.046 ng/mL (0.60 pM). This value is comparable to the lowest concentrations in the plasma of COVID-19 patients at the onset of symptoms, thus indicating that the SERRS immunoassay platform may be employed for early diagnosis.
@article={003071645,author = {BISTAFFA, Maria J.; CAMACHO, Sabrina Alessio; PAZIN, Wallance Moreira; CONSTANTINO, Carlos J. L.; OLIVEIRA JUNIOR, Osvaldo Novais de; AOKI, Pedro Henrique Benites.},title={Immunoassay platform with surface-enhanced resonance Raman scattering for detecting trace levels of SARS-CoV-2 spike protein},journal={Talanta},note={v. 244, p. 123381-1-123381-9},year={2022}}