Aptamer-Based Functionalized SERS Biosensor for Rapid and Ultrasensitive Detection of Gastric Cancer-Related Biomarkers

Ping Shao,1 Danyang Dong,1 Yong Huang,2 Yan Wang,1 Lian Pan,3 Qunshan Zhu,2 Zheng Wu,2 Fengjuan Jiang,4 Wei Wei2 1Department of Spleen and Stomach Diseases, Yixing Traditional Chinese Medicine Hospital, Wuxi, 214200, People’s Republic of China; 2Department of General Surgery, Jiangdu People’s Hospital Affiliated to Yangzhou University, Yangzhou, 225200, People’s Republic of China; 3Pathology Department, Yixing Traditional Chinese Medicine Hospital, Wuxi, 214200, People’s Republic of China; 4Department of Gastroenterology, Jiangdu People’s Hospital Affiliated to Yangzhou University, Yangzhou, 225200, People’s Republic of ChinaCorrespondence: Wei Wei, Email 18952531159@yzu.edu.cnBackground: Gastric cancer (GC) as is the second deadliest malignancy still lacks rapid, simple and economical detection and early clinical screening techniques. Surface-enhanced Raman spectroscopy (SERS) is a spectroscopic technique based on the surface plasmon resonance of precious metal nanoparticles, which can effectively detect low-abundance tumor markers. Combining SERS technology with sensors has high potential in the diagnosis and screening of GC.Methods: A novel Au/Si nano-umbrella array (Au/SiNUA) was prepared as a SERS substrate and the substrate was functionalized using the corresponding tumor marker aptamers for the detection of clinical biological samples using a one-step recognition release mechanism. Optimization of aptamer and complementary chain concentrations and detection time for optimal sensor preparation.Results: Au/SiNUA were tested to have good SERS enhancement activity. The proposed aptamer biosensor has good specificity and stability, with a low detection time of 18 min and a limit of detection (LOD) at the fM level, which is superior to most of the methods reported so far; and the accuracy of the clinical assay is comparable to that of the ELISA method. The expression levels of PDGF-B and thrombin in the serum of GC patients and healthy individuals can be effectively detected and differentiated.Conclusion: The ultrasensitive and specific aptamer biosensor is highly feasible for the diagnosis and screening of GC and has good application prospects.Keywords: surface-enhanced Raman scattering, gastric cancer, aptamer, biosensor, Au/SiNUA