DNA biosensor for detection of Helicobacter pylori using phen-dione as the electrochemically active ligand in osmium complexes
DNA biosensor for detection of Helicobacter pylori using phen-dione as the electrochemically active ligand in osmium complexes
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DOI：
10.1021/ac0489263
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发表时间：
2005-04-15
影响因子：
7.4
通讯作者：
Lorenzo, E
中科院分区：
文献类型：
--
作者：
del Pozo, MV;Alonso, C;Lorenzo, E
报道了一种研究DNA与氧化还原活性的1，10-二氮杂菲-5，6-二酮(phen-dione)膦配合物相互作用的表面方法。采用DNA吸附修饰金电极，以[Os(Bpy)(2)(phe-dione)](3+/2+)(bpy=2，2‘-联吡啶)或[Os(Phen)(2)(phen-dione)](3+/2+)(phen=1，10-phantroline)为电化学报告分子。该方法简单，节省试剂，允许在DNA层内积累Os络合物。根据固定金属络合物的氧化还原过程中的伏安电荷，确定了与DNA吸附层结合的臭氧络合物的量。由于邻苯二甲酸二酮配体在低电位下具有氧化还原反应，因此苯二酮配体中的苯醌部分可作为DNA电化学检测的指示剂。通过S-金键将硫醇连接的单链幽门螺杆菌DNA探针固定在修饰密度为86pmol/cm(2)的金电极上。与互补DNA序列杂交后，Os络合物在双链DNA层内电化学积累。在氧化还原活性的电位范围内(即，在非常低的电位下，-0.020 VVS-Sce)，通过差示脉冲伏安法进行电化学检测；用这种方法，可以在5-20pmol的范围内定量H.Pylori的序列，线性相关系数r=0.9888，检测下限类似于6pmol。
A surface-based method for the study of the interactions of DNA with redox-active 1,10-phenantroline-5,6-dione (phen-dione) osmiurn complexes is described. The study was carried out using gold electrodes modified with DNA via adsorption and [Os(bPY)(2)(phe-dione)](3+/2+) (bpy = 2,2'-bipyridyl) or [Os(phen)(2)(phen-dione)](3+/2+) (phen = 1,10-phenantroline) as electrochemical reported molecules. The method, which is simple and reagent-saving, allows the accumulation of osmium complexes within the DNA layer. The amount of osmium complex bound by the adsorbed layer of DNA was determined from the voltammetric charge associated with the osmium redox process of the immobilized metal complex. The quinone moiety of the phen-dione ligand was useful as an indicator for electrochemical DNA sensing because of its redox response at low potentials. A thiol-linked single-stranded Helicobacter pylori DNA probe was immobilized, through S-Au bonds on to a gold electrode (density of modification 86 pmol/cm(2)). Following hybridization with the complementary DNA sequence, the osmium complex was electrochemically accumulated within the double-stranded DNA layer. Electrochemical detection was performed by differential pulse voltammetry over the potential range where the quinone moiety was redox active (i.e., at very low potentials, -0.020 Vvs SSCE); with this approach, a sequence of the H. pylori could be quantified over the range from 5 to 20 pmol with a linear correlation of r = 0.9888 and a detection limit of similar to 6 pmol.