Label-free exonuclease I-assisted signal amplification colorimetric sensor for highly sensitive detection of kanamycin

A label-free colorimetric method based on exonuclease I (Exo I)-assisted signal amplification with protamine as a medium was developed for analysis of kanamycin. In this study, double-stranded DNA (dsDNA) probe tailored by manipulating an aptamer and its complementary (cDNA) ensuring detection target high selectivity excellent sensitivity. Herein, could not only combine negatively charged gold nanoparticles but also interaction polyanion DNA. Upon addition kanamycin, the target-aptamer complex formed cDNA released. Thus, both be digested Exo I, captured kanamycin liberated triggering recycling amplification. Under optimized conditions, proposed realized low limit 2.8 × 10?14 M along wide linear range plus selectivity. Our strategy exhibited enormous potentials fabricate various kinds biosensors target-induced configuration changes.