DNA‐Templated Magnetic Nanoparticle‐Quantum Dot Polymers for Ultrasensitive Capture and Detection of Circulating Tumor Cells

DNA‐templated magnetic nanoparticle‐quantum dot‐aptamer copolymers (MQAPs) are constructed through a hybridization chain reaction for rapid enumeration and identification of circulating tumor cells with high capture efficiency and capture purity approaching 80%. These MQAPs exhibit amplified magnetic response, extraordinary binding selectivity for target cells over background cells, and ultra bright ensemble quantum dot photoluminescence for single cell detection.