锰掺杂硫化锌量子点磷光探针对蜂蜜中四环素类抗生素残留的高灵敏检测

通过水合法合成了L-半胱氨酸修饰的锰掺杂硫化锌量子点(Mn∶ZnS QDs)。利用四环素类抗生素(Tetracyclines,TCs)对锰掺杂硫化锌量子点磷光激发光的內滤效应建立蜂蜜中TCs残留的快速、高灵敏检测方法。TCs在Mn∶ZnS QDs磷光最佳激发波长289 nm处有较强的紫外吸收,当Mn∶ZnS QDs体系中存在TCs时,激发光一定程度地被TCs吸收,磷光信号减弱。本研究以强力霉素(Doxycycline,DTC)为代表,建立Mn∶ZnS QDs磷光信号与DTC浓度的线性关系,进而实现对DTC的定量检测。结果表明,在优化条件下,Mn∶ZnS QDs磷光信号减小值的自然对数与DTC浓度在0.05~150μmol·L-1范围内呈良好的线性关系,线性方程为ln P 0/P=0.01758 C(DTC)+0.01351(R 2=0.999),检出限为0.0097μmol·L-1。同时,对实际样品蜂蜜做了加标回收率实验,回收率为92.4%~110%。本研究建立的Mn∶ZnS QDs磷光探针用于TCs残留检测具有良好重复性和稳定性,可用于蜂蜜中TCs残留的快速、高灵敏检测。

Highly Sensitive Detection of Tetracyclines Residues in Honey by Mn-doped ZnS Quantum Dots Phosphorescent Probe

L-cysteine modified Mn-doped ZnS quantum dots(Mn∶ZnS QDs)were synthesized by hydration.A rapid and highly sensitive method for the determination of tetracyclines(TCs)residues in honey was established by using the internal filtration effect of TCs on Mn∶ZnS QDs excited by phosphorescence.TCs have a strong ultraviolet absorption at the optimal phosphorescence excitation wavelength 289 nm of Mn∶ZnS QDs.When TCs is present in the Mn∶ZnS QDs solution,the excitation wavelength is absorbed by TCs to a certain extent,and the phosphorescence signal decreased.To be represented by doxycycline(DTC),the linear relationship between Mn∶ZnS QDs phosphorescence signal and DTC concentration was established,and the quantitative detection of DTC was realized.Under the optimized conditions,the phosphorescence intensity decreased with the increase of DTC concentration and the relative phosphorescence intensity change ln(P 0/P)showed a good linear relationship with the increase of DTC in the range from 0.05 to 150μmol·L-1.The regression equation was ln P 0/P=0.01758 C(DTC)+0.01351(R 2=0.999),the detection limit is 0.0097μmol·L-1.The actual sample honey was tested,the recovery rate was 92.4%~110%.The Mn∶ZnS QDs phosphorescence probe developed in this study has good repeatability and stability for the detection of TCs residues.It can be used for the rapid and highly sensitive detection of TCs residues in honey.