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In this paper, we report a novel antibody conjugated gold nanostars () as surface-enhanced Raman spectroscopy (SERS) probes for distinguishing cancer cells (A549 cells, H1229 cells) from normal cells (ATII cells). In such a probe, bovine serum albumin (BSA) was served as the protective agent and stabilizing agent, 4-mercaptobenzoic acid (4-MBA) was used as the Raman reporter to generate SERS signals as well as the conjugation agent for attaching CD44 antibody (anti-CD44) molecules to , where anti-CD44 could effectively target to CD44 protein over-expressed cells. All the results of the experiments confirmed that more SERS probes have been targeted to cancer cells (A549 cells and H1229 cells) than that of normal cells (ATII cells) under the same condition. The anti-CD44 SERS probes hold a potential application in distinguishing cancer cells from normal cells with high sensitivity and good biocompatibility. BSA-stabilized Au nanostars were synthesized with a seed-mediated growth approach in two steps, in which trisodium citrate dehydrate was used as the reducing agent. In SERS probes, 4-MBA was absorbed on the surface of Au nanostars as both the Raman reporter molecule and the conjugation agent for antibody, which could target to different cells through the combination of featured proteins on the cell membrane. [ABSTRACT FROM AUTHOR]

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]