An aptamer-based signal-on bio-assay for sensitive and selective detection of Kanamycin A by using gold nanoparticles

• A fluorescence switch on assay for Kanamycin A detection was developed.
• Aptamer and gold nanoparticles were used to realize this assay.
• This assay exhibited high sensitivity and selectivity.
• This assay could be used in milk samples for Kanamycin A detection.
• Binding affinity between aptamer and Kanamycin A was studied by using MST.

In this study, a simple and sensitive aptamer-based fluorescence method for the detection of Kanamycin A by using gold nanoparticles (AuNPs) has been developed. In this assay, AuNPs were utilized as DNA nanocarrier as well as efficient fluorescence quencher. In the absence of Kanamycin A, dye-labeled aptamer could be adsorbed onto the surface of AuNPs and the fluorescence signal was quenched. In the presence of Kanamycin A, the specific binding between dye-labeled aptamer and its target induced the formation of rigid structure, which led to dye-labeled aptamer releasing from the surface of AuNPs and the fluorescence intensity was recovered consequently. Under optimum conditions, calibration modeling showed that the analytical linear range covered from 0.8 nM to 350 nM and the detection limit of 0.3 nM was realized successfully. This proposed bio-assay also showed high selectivity over other antibiotics. Meanwhile, this strategy was further used to determine the concentrations of Kanamycin A in milk sample with satisfying results.

A novel biosensing strategy for Kanamycin A detection based on FRET assay using gold nanoparticles as aptamer nanocarrier as well as efficient fluorescence quencher.Figure optionsDownload as PowerPoint slide