基于2-羟丙基-β-环糊精修饰的CdTe荧光探针定量分析结晶紫及机理探讨

Research on Quantitative Analysis of Crystal Violet Using a CdTe Fluorescence Probe Modified by 2-Hydroxypropyl-β-Cyclodextrin and Its Mechanism

在稳定剂巯基乙酸(TGA)和修饰剂2-羟丙基-β-环糊精(2-Hp-β-CD)存在下,获得的2-Hp-β-CDCdTe量子点具有高的荧光强度、水溶性和光稳定性,以及对结晶紫(CV)的良好包含能力。利用紫外-可见吸收光谱、荧光光谱及TEM图谱,研究了2-Hp-β-CDCdTe量子点与CV的相互作用情况。通过十六烷基三甲基溴化铵(CTAB)作用,显著降低了供体与受体之间的距离,促使量子点与结晶紫发生能量转移,且量子点的荧光光谱与CV的吸收光谱有效重叠,据此建立了量子点与CV的荧光共振能量转移(FRET)体系,并用于CV含量的测定。结果表明,在pH 8.0的Tris-HCl缓冲液中,当存在CTAB时,CV能对2-Hp-β-CDCdTe量子点的荧光峰发生猝灭,且CV浓度在1.0×10^-7~1.0×10^-5 mol/L范围内与量子点的荧光强度变化(ΔF)呈良好线性关系(r^2=0.9952),检出限为1.74×10^-8 mol/L,平均回收率为99.0%~106%。

A fluorescence probe,2-Hp-β-CDCdTe QDs for the detection of crystal violet(CV)was fabricated in the presence of TGA as stabilizer and 2-hydroxypropyl-β-cyclodextrin(2-Hp-β-CD)as modifier,which showed high fluorescence intensity,water solubility and light stability,as well as good inclusion ability for CV.The interaction between 2-Hp-β-CDCdTe QDs and CV was investigated by UV-Vis,fluorescence spectroscopy and TEM.The data indicated that the distance between the donor and the acceptor was reduced significantly by the action of CTAB,and the energy transfer between the QDs and CV was promoted.The fluorescence spectrum for QDs could overlap the absorption spectrum of CV effectively.Based on this,the fluorescence resonance energy transfer(FRET)system between QDs and CV was established,which could be used for the determination of CV.Results showed that in pH 8.0 Tris-HCl buffer,CV could quench the fluorescence peak of 2-Hp-β-CDCdTe QDs in the presence of CTAB,and there was a good linear relationship between the change of fluorescence intensity(ΔF)and CV concentration in the range of 1.0×10^-7-1.0×10^-5 mol/L(r^2=0.9952).The detection limit was 1.74×10-8 mol/L,and the average recoveries were in the range of 99.0%-106%.