A novel fluorescent assay for the ultrasensitive detection of miRNA-21 with the use of G-quadruplex structures as an immobilization material for a signal indicator.
In this work, a novel fluorescent assay was proposed for the ultrasensitive detection of microRNA-21 (miRNA-21) based on the efficient immobilization of protoporphyrin IX (PPIX) as signal indicators in massive G-quadruplex structures obtained by target recycling, three-dimensional DNA walker and a rolling circle amplification (RCA) coupled cascade nucleic acid amplification strategy.