Abstract:A method for tetracycline detection was reported. It is based on fluorescence resonance energy transfer(FRET) from KGdF4：Tb3+ nanoparticals as a donor, and on graphene oxide that acts as an acceptor. The KGdF4：Tb3+ nanoparticals were modified with tetracycline aptamer. On the basis of the strong π-π effect between the nucleobases of the aptamer and graphene oxide, KGdF4：Tb3+ nanoparticals were brought in close proximity to the graphene oxide surface. Therefore, the strong fluorescence of KGdF4：Tb3+ nanoparticals can be significantly quenched. However, on addition of the target analyte, the tetracycline-aptamer-KGdF4：Tb3+ complex is formed and quenching by graphene oxide is suppressed. The fluorescence is linearly proportional to the concentration in the range from 0.5 to 100 ng/mL(R2=0.993), with detection limits as low as 0.25 ng/mL. The assay had high specificity and sensitivity, and was successfully applied to real food samples.
