吖啶橙-罗丹明6G共振能量转移荧光猝灭法测定铅

Determination of lead ion by resonance energy transfer fluorescence quenching of acridine orange-rhodamine 6 G

目的根据吖啶橙和罗丹明6 G两分子间能够有效地发生荧光共振能量转移,建立一种检测铅离子的新方法。方法在表面活性剂SDS的存在下,吖啶橙和罗丹明6 G分子间发生荧光共振能量转移,使罗丹明6 G的荧光强度增大;加入铅离子后能对AO-R6 G体系的荧光产生猝灭作用,其荧光猝灭程度随着铅离子浓度的增大而增强,据此建立了检测Pb2+的新方法。结果当Pb2+浓度为2.0×10-7mol/L^3.0×10-6mol/L时,与荧光猝灭程度ΔF有良好的线性关系,线性回归方程为y=16.34x+42.79,相关系数(r)=0.998,检出限为6.06×10-8mol/L,相对标准偏差(RSD)为3.4%~5.3%,加标回收率为95.1%~96.5%。结论本方法操作简便、灵敏,可用于实际水样中铅含量的测定。

Objective A novel method for the determination of Pb2＋ was established based on resonance energy transfer fluorescence quenching of acridine orange - rhodamine 6 G. Methods In the presence of sodium dodecyl sulfate, the effective energy transfer could occur between AO - R6 G, which made the fluorescence intensity of R6 G increased markedly. Pb2＋ can extinguish the fluorescence intensity of R6 G, and the decreased fluorescence intensity was proportional to the concentration of Pb2. . Base on this phenomenon, a novel method for the determination of Pb2＋ was developed. Results The fluorescence quenching intensity AF showed good linearity as the concentration of Pb2＋ was in the range of 2.0 × 10 -7 mol/L - 3.0 ×10 -6 mol/L. The linear regression equation was y = 16.34x ＋42.79 and the correlation coefficient was 0.998. The detection limit was of 6.06 x 10-s mol/L, the relative standard deviation（RSD） was of 3.4% -5.3% and the recoveries were 95.1% -96.5%. Conclu- sion The method is simple and sensitive, and can be used for the determination of the lead content in water samples.