基于KGdF_4:Tb^(3+)纳米材料检测四环素的生物传感新方法

A Biosensor Based on KGdF_4:Tb^(3+) Nanoparticals for Tetracycline Determination

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KGd F4: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KGd F4: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,KGd F4: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KGd F4: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/m L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/m L。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。

A method for tetracycline detection was reported.It is based on fluorescence resonance energy transfer （FRET） from KGdF4∶Tb^3＋ nanoparticals as a donor,and on graphene oxide that acts as an acceptor.The KGdF4∶Tb^3＋ 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∶Tb^3＋ nanoparticals were brought in close proximity to the graphene oxide surface.Therefore,the strong fluorescence of KGdF4：Tb^3＋ nanoparticals can be significantly quenched.However,on addition of the target analyte,the tetracycline-aptamer-KGdF4∶Tb^3＋ 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.