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Cervical cancer is a common cause of cancer-related death in women worldwide, and quantitative detection of serum tumor markers has practical implications for diagnosing cervical cancer. In this study, a novel surface-enhanced Raman scattering (SERS)-based immunosensor for the hypersensitive simultaneous detection of survivin and osteopontin (OPN) in cervical cancer serum was proposed, which was composed of the AuNPs@SiO2 microspheres (Au@SiO2) array immunosubstrate and Au-Ag nanoshells (Au-AgNSs) immunoprobes. The experimental results demonstrated that the constructed SERS immunosensor exhibited satisfactory selectivity and reproducibility while possessing detection limits as low as 0.908 pg/mL and 0.813 pg/mL for survivin and OPN in human serum. Finally, its usefulness in real serum samples (from healthy subjects, cervical intraepithelial neoplasia 1 (CIN 1), CIN 2, CIN 3 and cervical cancer patients) was verified, and the detection data were in good agreement with the enzyme-linked immunosorbent assay results. This immunosensor has excellent performance, which is promising for the early screening of cancer. The ordered single-layer gold film and monolayer SiO2 array were obtained by the oil–water interface self-assembly method and Langmuir-Blodgett (LB) gas–liquid interface assembly method, respectively. Then, these two ordered structures are combined to prepare Au@SiO2 array substrates. This ordered array substrate not only ensures good uniformity, but also improves SERS performance. [ABSTRACT FROM AUTHOR]

Ultrasensitive detection of specific biomarkers in clinical serum is helpful for early diagnosis of cervical cancer. In this paper, a surface-enhanced Raman scattering (SERS)-based immunoassay was developed for the simultaneous determination of squamous cell carcinoma antigen (SCCA) and osteopontin (OPN) in cervical cancer serum. Au-Ag nanoshuttles (Au-AgNSs) as SERS tags and hydrophobic filter paper-based Au nanoflowers (AuNFs) as capture substrate were constructed into a sandwich structure which served as an ultrasensitive SERS-based immunoassay platform. Finite difference time domain simulation confirmed that the electromagnetic field coupled between the AuNFs had a prominent SERS signal enhancement effect, which improved the detection sensitivity. SERS mapping showed that hexadecenyl succinic anhydride hydrophobic treatment could prevent the analyte from being quickly absorbed by the filter paper and increase the retention time to be more evenly distributed on the filter paper substrate. The immunoassay platform was verified to have good selectivity and reproducibility. With this method, the detection limits of SCCA and OPN in human serum were as low as 8.628 pg/mL and 4.388 pg/mL, respectively. Finally, in order to verify the feasibility of its clinical application, the serum samples of healthy subjects; cervical intraepithelial neoplasia I (CINI), CINII, and CINIII; and cervical cancer patients were analyzed, and the reliability of the results was confirmed by enzyme-linked immunosorbent assay experiments. The constructed SERS-based immunoassay platform could be used as a clinical tool for early screening of cancers in the future. [ABSTRACT FROM AUTHOR]

The high incidence of premature rupture of membranes (PROM) is closely related to the lack of screening methods. Herein, a rapid and sensitive detection model for procalcitonin (PCT) and interleukin-6 (IL-6) was established utilizing the principle of antigen antibody binding and combined with surface enhanced Raman spectroscopy (SERS) and immunochromatographic assay (ICA), which could be used for the detection of specific biomarkers at a low concentration of peripheral blood and early detection of PROM patients. 5,5′-Dithiobis-2-nitrobenzoic acid labeled monoclonal anti-IL-6 on gold nanocages (GNCs) and 4-methylthiobenzoic acid labeled monoclonal anti-PCT on GNCs were employed as SERS tags. In the presence of IL-6 and PCT, the antigen-SERS tag complexes were trapped and concentrated on the two test lines. The unique characteristics of GNCs with hollow and multi-branch angle allowed high SERS performance in the system by increasing the biological binding sites and hot spots. Through finite difference time domain simulation, it could be concluded that the electromagnetic field between the gaps of GNC dimers was stronger than that of the single GNC, which proved the feasibility of ICA based on surface enhanced Raman scattering (SERS-ICA) in theory. The detection limits of IL-6 and PCT in phosphate buffer were 7.897 pg mL−1 and 7.725 pg mL−1, meanwhile the detection limits of peripheral blood were 8.414 pg mL−1 and 8.017 pg mL−1, respectively. In addition, the detection of real-world samples showed that SERS-ICA was available to evaluate the concentrations of IL-6 and PCT. The experimental data of SERS-ICA were in accordance with that of enzyme-linked immunosorbent assay. These results indicated that SERS-ICA had great potential in the early screening of PROM. [ABSTRACT FROM AUTHOR]