基于联吡啶钌在CdTe量子点/氮掺杂石墨烯修饰电极上的电致化学发光法测定三丙胺

Electrochemiluminscence Determination of Tripropylamine Based on Tris(2,2′-bipyridyl)ruthenium(Ⅱ)at CdTe Quantum Dots with Nitrogen-doped Graphene Modified Electrode

本文制备了CdTe量子点/氮掺杂石墨烯复合材料(CdTe QDs@NG),并采用透射电镜和红外光谱表征了该复合材料。因为CdTe QDs和氮掺杂石墨烯之间的协同作用,将他们修饰至基底电极上改善了电极表面的电子传递性能、发光效率以及比表面积,从而在三丙胺(TPA)存在下,联吡啶钌在CdTe QDs@NG复合材料修饰电极上的电致化学发光(ECL)强度远远超过在裸玻碳电极上的响应效果,因此根据TPA对联吡啶钌电致发光信号的增敏作用建立了测定TPA的新体系。结果表明,在最佳实验条件下,联吡啶钌电致发光强度差值ΔIECL与TPA浓度在4.0×10-9~4.0×10-7 mol/L范围内呈良好的线性关系,检测限(S/N=3)低至1.4×10-9 mol/L。该方法的选择性高、灵敏度强、重现性好,10次重复测定8.0×10-8 mol/L的TPA,相对标准偏差仅为2.03%。采用该方法测定了环境水样中的TPA浓度,加标回收率在97.7%~104.6%范围,表明该方法可用于推广测定实际样品中的TPA浓度。

We report a simple method for fabricating CdTe quantum dots decorated with nitrogen-doped graphene(CdTe QDs@NG).The material was characterized by transmission electron microscopy and fourier transform infrared spectroscopy.Compared to the bared glassy carbon electrode(GCE),CdTe QDs@NG modified glassy carbon electrode obtains enhanced electrochemiluminescence(ECL)performance of Ru(bpy)23+(bpy=2,2′-bipyridyl)when tripropylamine(TPA)was used as a coreactant.This is attributed to the improved electron transfer capability,high photoluminescence efficiency and large surface area of CdTe QDs@NG.Hence,a novel strategy of Ru(bpy)23+at CdTe QDs@NG/GCE has been employed for the determination of TPA.The ECL intensity of Ru(bpy)23+increased gradually with the increasing concentration of TPA over a range of 4.0×10-9-4.0×10-7 mol/L under optimal conditions.The detection limit can be reduced further to 1.4×10-9 mol/L(S/N=3).The method displays excellent specificity,extremely good sensitivity and high reproducible with the RSD of 2.03%for 10 times parallel determination of 8.0×10-8 mol/L TPA.At last,the proposed method was applied for the determination of TPA in environmental samples with satisfactory reproducibility,demonstrating its applicability in real sample analysis.