Nonenzymatic chemiluminescence detection of circulating tumor cells in blood based on Au@luminol nanoparticles, hybridization chain reaction and magnetic isolation

Circulating tumor cell (CTC) analysis has great significance for cancer diagnosis and monitoring. However, selective capture and quantification of CTCs from whole blood remains challenging due to the extremely scare number of CTCs. Here, we developed a simple method for ultrasensitive detection of circulating tumor cells (CTCs) based on enzyme-free chemiluminescence reaction, hybridization chain reaction (HCR) signal amplification and magnetic enrichment and isolation. In this detection system, the CTCs-spectific aptamer AS1411 modified magnetic nanoparticles were employed to identify and isolate CTCs from whole blood samples; Au@luminol nanoparticles-HCR assembly (ALHA) containing multiple MUC1 aptamer (specific to a type of CTCs, MCF-7) acted as both the response signal and specific recognition element for sensing CTCs;. On the basis of the chemiluminescence properties of Au@luminol nanoparticles in K2S2O8 solution, the captured CTCs can be sensitively detected using enzyme-free chemiluminescence technique. Furthermore, due to the amplified effect of HCR, the detection sensitivity could be as low as 3 MCF-7 cells /mL. Sensitive, selective results and simple instrument made this method should be useful for further CTCs-related routine applications.