Detection of squamous cell carcinoma antigen in cervical cancer by surface-enhanced Raman scattering-based immunoassay

In this study, a highly specific, sensitive and reliable immunosensor has been developed for the quantitative detection of the squamous cell carcinoma antigen (SCCA) in cervical cancer, based on surface-enhanced Raman scattering (SERS). The gold nanoparticle-coated polydopamine resin microspheres (PDR@GNPs) were fabricated and conjugated with the SCCA monoclonal antibody as capturing substrates. Then, the hollow gold nanocages (GNCs) were adsorbed by 4-mercaptobenzoic acid (4-MBA) and further modified by the SCCA polyclonal antibody as SERS tags. Based on this sandwich immunoassay strategy, SCCA polyclonal antibody-conjugated HGNs SERS tags and SCCA monoclonal antibody-conjugated capturing substrates were used to detect SCCA antigen solutions of different concentrations. The calibration curves were established in the range from 1 × 10−5to 1 × 10−10M. The detection limit of phosphate buffer (PBS) was 7.16 pg mL−1and that of human peripheral blood was 8.03 pg mL−1. Finally, this novel SERS immunosensor was applied in the quantitative detection of SCCA in peripheral blood obtained from cervical intraepithelial neoplasia I (CINI), CINII, cervical cancer and healthy subjects, according to the calibration curve. Enzyme-linked immunosorbent assay (ELISA) was consistent with the SERS results. The results demonstrated that the SERS immunoassay technique had potential application prospects in the early screening and diagnosis of cervical cancer.