Ultrasensitive electrochemiluminescence aptasensor for kanamycin detection based on silver nanoparticle-catalyzed chemiluminescent reaction between luminol and hydrogen peroxide

An ultrasensitive electrochemiluminescence (ECL) aptasensor for detection of kanamycin (KAN) was constructed by using the chemiluminescence properties of luminol-hydrogen peroxide (H2O2) in alkaline solution. Silver nanoparticles (AgNPs) could act as effective catalyzer to accelerate H2O2 decomposition to produce various intermediate reactive oxygen species for signal amplification and thus increased the ECL intensity of luminol. When the target KAN was in the presence, ECL signal decreased obviously owing to the specific interaction between KAN and aptamer. Thus, the concentration of KAN could be determined according to the intensity of ECL. To further demonstrate the effect of aptasensor, we had conducted cyclic voltammetry on an electrochemical workstation and electrogenerated chemiluminescence analyzer, respectively. Upon the optimization of assay conditions, the proposed aptasensor displayed a wide linear range from 0.5 to 100 ng mL−1 with limit of detection of 0.06 ng mL−1. The as-proposed aptasensor was not only capable of achieving a satisfactorily low detection limit but also possessed advantages of excellent accuracy, specificity and stability. Furthermore, this constructed ECL sensing platform was successfully applied to detect KAN in real samples and it would be of excellent potential to detect other antibiotics using the proposed method.