Enhanced peroxidase-like activity of boron nitride quantum dots anchored porous CeO2 nanorods by aptamer for highly sensitive colorimetric detection of kanamycin

Abstract

Kanamycin (KAN) residue in the environment and food have a huge risk to human health, therefore, designing simple and sensitive determination methods for KAN is in high demand. Here, a simple and low-cost colorimetric analysis was established for highly sensitive determination of KAN through integrating boron nitride quantum dots anchored porous CeO2 nanorods (BNQDs/CeO2) and aptamer. The BNQDs/CeO2 as nanozyme showed prominent peroxidase-like activity, which could effectively catalyze 3,3′,5,5′-tetramethylbenzidine (TMB) oxidation by H2O2 because of large surface area and synergetic interaction between BNQDs and CeO2. Moreover, it presented an obviously enhanced catalytic activity after combing with KAN-specific aptamer, resulting from the increased dispersibility and substrate affinity of BNQDs/CeO2 nanozyme. While KAN could restrain such a catalytic enhancement through aptamer-target recognition event. On the basis of aptamer-regulated mimic enzyme activity, the proposed colorimetric method realized quantitative KAN determination ranging from 0.01 nM to 100 nM with an ultralow detection limit of 4.6 pM. This analysis method is facile in design and can be applied to other biomolecular recognition processes, promising as a universal detection platform for environmental monitoring and food safety.