A Supersensitive CTC Analysis System Based on Triangular Silver Nanoprisms and SPION with Function of Capture, Enrichment, Detection, and Release

Detection of circulating tumor cells (CTCs) may be applied for diagnosis of early tumors like a liquid biopsy. However, the sensitivity remains a challenge because CTCs are extremely rare in peripheral blood. In this study, we developed a supersensitive CTC analysis system based on triangular silver nanoprisms (AgNPR) and superparamagnetic iron oxide nanoparticles (SPION) with function of capture, enrichment, detection, and release. The AgNPR was encoded with MBA (i.e., 4-mercaptobenzoic acid) and modified with rBSA (i.e., reductive bovine serum albumin) and FA (i.e., folic acid) generating organic/inorganic composite nanoparticle MBA-AgNPR-rBSA-FA, which has the function of surface-enhanced Raman scattering (SERS). The optimized SERS nanoparticles (i.e., MBA3-AgNPR-rBSA4-FA2) can be utilized for CTC detection in blood samples with high sensitivity and specificity, and the LOD (i.e., limit of detection) reaches to five cells per milliliter. In addition, the SPION was also modified with rBSA and FA generat...