A photoluminescent biosensor based on long-range self-assembled DNA cascades and upconversion nanoparticles for the detection of breast cancer-associated circulating microRNA in serum samples

A photoluminescent biosensor was developed for the detection of microRNA (miRNA) combined signal amplification of long-range self-assembled DNA cascades with upconversion nanoparticles. The sensor exhibited superior sensitivity with a detection limit of microRNA-21 (miR-21) as low as 1 fM, which may represent the potential of being used in miRNA analysis and clinical diagnosis of breast cancer.