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Detection of tumor biomarkers is of great significance for early diagnosis of cancer. Herein, we fabricated a novel lab-on-a chip surface-enhanced Raman scattering (SERS) (LoC-SERS) biosensing platform for highly sensitive and specific detection of thrombin and platelet-derived growth factor-B (PDGF-B) using aptamer recognition technology. This strategy relies on the specific aptamer recognition between SERS probes (Ag–Au core–shell nanorods (Ag–AuNRs) modified with Raman reporter molecules and detection aptamer) and SERS capture substrate (Au nanoflower (AuNF) substrates modified with capture aptamer), which significantly amplify the plasmonic coupling effect that allows the ultrasensitive and high specificity SERS detection. The limits of detection (LODs) are as low as 3.62 fM for thrombin and 2.86 fM for PDGF-B. Such LoC-SERS platform is further employed to simultaneously detect two types of gastric carcinoma-related with high sensitivity and specificity, which meanwhile exhibit robust capacity of resisting disturbance in practical samples. The results revealed that the present LoC-SERS platform displayed excellent analytical performance, including superior reproducibility, specificity, and sensitivity. Satisfactory results were obtained in real sample analysis with the LoC-SERS platform. [ABSTRACT FROM AUTHOR]

A novel surface-enhanced Raman scattering and lateral flow assay (SERS–LFA) biosensor with multiple channels based on an aptamer has been proposed in this work. The developed biosensor was designed for the rapid, convenient, sensitive and specific detection of vascular endothelial growth factor (VEGF) and osteopontin (OPN) in several samples simultaneously. During the assay, VEGF and OPN were recognized by detection aptamers immobilized on cuprous oxide nanocubes (Cu2O NCs) and captured by capture aptamers to form a sandwich structure on the test lines. In this way, generous numbers of "hot spots" formed by the aggregation of Cu2O NCs remarkably enhanced the SERS signals of Raman reporters (NBA and 4-ATP). The detection limits were as low as 0.78 pg mL−1 for the VEGF and 0.86 pg mL−1 for OPN in the human serum within 15 min, respectively. Additionally, the biosensor possesses favorable specificity, reproducibility, uniformity and stability. In the clinical analysis of serum specimens, patients with cervical cancer can be differentiated from healthy volunteers. Consequently, the presented aptamer-based SERS–LFA biosensor with multiple channels provides a powerful tool for the early diagnosis of cervical cancer. [ABSTRACT FROM AUTHOR]