Determination of carbendazim by aptamer-based fluorescence resonance energy transfer (FRET)

Because of diverse adverse effects of carbendazim (CBZ) upon the human body and environment, a simple method for the determination of this molecule is urgently needed. Therefore, a method based on an aptamer was developed. An aptamer of carbendazim, CZ12, labeled with a fluorescent molecule (FAM), was adsorbed on graphene oxide (GO) by pi-pi stacking. The fluorescence resonance energy transfer (FRET) between the molecule and GO was used to rapidly quench the fluorescence signal. In the presence of carbendazim, the fluorescent molecule selectively combines with carbendazim, thereby greatly reducing the binding efficiency of the former with GO. Thus, by mixing a FAM-labeled carbendazim aptamer, GO, and food samples, the carbendazim content was determined from the fluorescence measurements. The limit of quantification was 10.0 ng/mL for strawberry, banana, pitaya, and Panax notoginseng samples. The linear range was from 0 to 125 ng/mL with a linear correlation coefficient equal to 0.9918.