基于二氧化钛纳米管的电化学发光传感器及其对铅离子的测定研究

Preparation of TNTs based ECL sensor and its application in the studies of determination of Pb(Ⅱ)

合成了二氧化钛纳米管(TNTs)/三吡啶钌(Ru(bpy)23+)纳米复合物,用Nafion分散后修饰到玻碳电极上,制备成一种新型的电化学发光(ECL)传感器.分析并确定了电解质和pH是影响该传感器ECL的重要因素.探讨了电活性物质Ru(bpy)32+和乙二胺四乙酸(EDTA)的发光反应机理,并利用制备的传感器研究了低浓度下的铅离子对Ru(bpy)23+-EDTA体系发光强度的抑制作用.实验表明:该体系发光强度的变化值与铅离子浓度在5.048×10-7～4.603×10-5mol/L范围内呈现良好的线性关系,检测限可达1.0×10-8mol/L,具有检测铅离子含量的潜在应用价值.

A novel method for preparing the electrochemiluminescence （ECL） sensor was developed. Firstly,Titanate nanotubes （ TNTs ）/tris （ 2,2＇ -bipyridine） ruthenium （ Ru （ bpy ）3^2＋ ） nanocomposites were fabricated. After dispersing in Nafion, the nanocomposites were modified onto the surface of glassy carbon electrode （GCE） to construct an ECL sensor. In order to optimize the performance of the new ECL sensor, we analyzed the factors affecting the capability of ECL sensor which showed the key roles of electrolyte and pH. In addition, ethylenediamine tetraacetic acid （EDTA） was employed to be the co-reactant to produce ECL with the Ru （bpy）3^2＋ immobilized on the surface of GCE as the electroactive compound of this sensor. The ECL mechanism of Ru （bpy）3^2＋ and EDTA was discussed and inhibiting effect of Pb（Ⅱ） to this ECL system was investigated. Meanwhile the analytical method of Pb （ Ⅱ ） by ECL was proposed, which displayed a good linear relationship between the difference of ECL intensity and concentration of Pb （ Ⅱ ） in the range of 5. 048 × 10^-7 -4. 603 × 10^-5 mol/L with the detection limit of 1.0 × 10^-8 mol/L, showing a good potential in determination of Pb （ Ⅱ ）.