基于KGdF4:Tb3+纳米材料检测四环素的生物传感新方法

A Biosensor Based on KGdF4：Tb3+ Nanoparticals for Tetracycline Determination

摘要:

构建了一种荧光共振能量转移生物传感系统检测四环素的方法。以KGdF4：Tb3+纳米粒子为荧光能量供体, 氧化石墨烯为荧光能量受体, 基于氧化石墨烯对单链DNA的π-π共轭作用, 使得适配体功能化的KGdF4：Tb3+纳米粒子与氧化石墨烯足够靠近, 从而发生荧光共振能量转移, KGdF4：Tb3+纳米粒子的荧光被淬灭。当体系中存在四环素时, 四环素优先与其适配体特异结合形成复合物, 与氧化石墨烯结合能力减弱, 使得KGdF4：Tb3+纳米粒子的荧光淬灭程度降低, 据此可实现对四环素的定量检测。该方法在四环素质量浓度0.5~100 ng/mL范围内与体系荧光强度呈现良好的线性关系(R2=0.993), 最低检出限为0.25 ng/mL。该方法特异性好, 灵敏度高, 已成功应用于实际样品中四环素的测定。

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.