A highly selective sandwich-type FRET assay for ATP detection based on silica coated photon upconverting nanoparticles and split aptamer

► A sandwich-type FRET assay for ATP detection has been developed. ► This assay was based on Si@UCNPs and ATP-induced recombination of split aptamer. ► The proposed strategy has high selectivity to ATP. ► This assay provided a detection limit of 1.70 μM for ATP.