A fluorescent aptamer-based method for kanamycin detection incorporating G-quadruplex DNAzyme and exonuclease III-assisted signal amplification.

A fluorescent aptamer sensor for kanamycin was constructed based on G-quadruplex DNAzyme and Exo III-assisted signal amplification. Target binding triggered cDNA release, activating Exo III to cleave HP and release G-quadruplex, which formed a DNAzyme with hemin to catalyze OPD oxidation and generate fluorescence. The method achieved a detection limit as low as 0.063 nM.