Electrochemiluminecence nanogears aptasensor based on MIL-53(Fe)@CdS for multiplexed detection of kanamycin and neomycin.

A dual gears electrochemiluminecence (ECL) aptasensing strategy for multiple selective determination of kanamycin and neocycin was designed on the basis of the combination of kanamycin and neocycin induced dual gears conversion, the loading platform of metal-organic frameworks (MOFs), surface plasmon resonance (SPR) and ECL resonance energy transfer (ERET) between CdS QDs and AuNPs (or PtNPs). In the absence of target, the dual gears were "off". Then the B1-AuNP (gear B) and aptamer 1-PtNPs acted as signal quenching elements to quench ECL intensity due to ERET process. Upon addition of kanamycin, the aptamer 1-PtNPs were removed from the gear gradually, the ECL was enhanced due to SPR process between AuNPs and CdS QDs. After the incubation of aptamer 2, the dual gears were "off" again and ECL intensity was decreased by ERET process between AuNPs and CdS QDs. In the presence of neomycin, dual gears were "on" again, the ECL signal was enhanced by SPR process between AuNPs and CdS QDs. Under optimal condition, the proposed aptasensor exhibited wide linear ranges of kanamycin (10-10-10-6 M) and neomycin (10-9-10-5 M), and relatively low detection limits to kanamycin (1.7 × 10-11 M) and neomycin (3.5 × 10-10 M). The developed aptasensor realized the multiple ECL detection of kanamycin and neomycin with single luminophore, and was successfully applied to the detection of kanamycin and neomycin in food samples.