Tao Ying, Lin Zhi-Jie, Chen Xiao-Mei, Chen Xi, Wang Xiao-Ru
Department of Chemistry and Key Laboratory of Analytical Sciences of the Ministry of Education, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
Anal Chim Acta. 2007 Jul 2;594(2):169-74. doi: 10.1016/j.aca.2007.05.025. Epub 2007 May 21.
In this paper, a novel electrochemiluminescence (ECL) sensor was constructed to determine herring sperm (HS) double-stranded (ds) DNA. Tetramethoxysilane and dimethyldimethoxysilane were selected as co-precursors to form an organically modified silicate (ORMOSIL) film for the immobilization of multiwall carbon nanotubes (MWNTs) wrapped by poly(p-styrenesulfonate) (PSS), and then Tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)3(2+)) was successfully immobilized on a glassy carbon electrode via ion-association. PSS was employed to increase the conductivity of the ORMOSIL film and disperse the cut MWNTs, which were cut and shortened in a mixture of concentrated sulfuric and nitric acids, in the film. It was found that MWNTs could adsorb Ru(bpy)3(2+) and acted as conducting pathways to connect Ru(bpy)3(2+) sites to the electrode. MWNTs also played a key role as materials for the mechanical and thermal properties. The ECL performance of this modified electrode was evaluated in a flow injection analysis (FIA) system, and the detection limit (S/N=3) for HS ds-DNA was 2.0x10(-7) g mL(-1) with a linear range from 1.34x10(-6) to 6.67x10(-4) gm L(-1) (R2=0.9876). In addition, the ECL sensor presented excellent characteristics in terms of stability, reproducibility and application life.
本文构建了一种新型电化学发光（ECL）传感器用于测定鲱鱼精（HS）双链（ds）DNA。选用四甲氧基硅烷和二甲基二甲氧基硅烷作为共前驱体，形成有机改性硅酸盐（ORMOSIL）膜，用于固定被聚（对苯乙烯磺酸盐）（PSS）包裹的多壁碳纳米管（MWNTs），然后通过离子缔合将三（2,2'-联吡啶）钌（II）（Ru(bpy)3(2+)）成功固定在玻碳电极上。PSS用于提高ORMOSIL膜的导电性，并使在浓硫酸和浓硝酸混合液中被切断并缩短的MWNTs分散在膜中。发现MWNTs可以吸附Ru(bpy)3(2+)，并作为导电通路将Ru(bpy)3(2+)位点连接到电极。MWNTs作为具有机械和热性能的材料也起着关键作用。在流动注射分析（FIA）系统中评估了该修饰电极的ECL性能，HS双链DNA的检测限（S/N = 3）为2.0x10(-7) g mL(-1)，线性范围为1.34x10(-6)至6.67x10(-4) g mL(-1)（R2 = 0.9876）。此外，该ECL传感器在稳定性、重现性和使用寿命方面表现出优异的特性。
