DNA在纳米金标上的组装、杂交、检测与银增强

利用电化学方法进行DNA的杂交检测.将目标ss-DNA固定在玻碳电极表面, 使其与纳米金标记的互补DNA发生杂化反应, 通过银增强试剂（该种试剂可以使银在纳米金表面沉积, 达到信号增强的效果）在纳米金上沉积银, 形成银包金的核壳结构.在酸性介质中沉积的银被氧化释放, 以离子状态存在于溶液中.用阳极溶出伏安法(ASV)检测银离子从而达到间接检测目标DNA的目的.测定结果表明，ss-DNA的浓度在100～1 000 pmol?L－1 范围内有非常好的线性关系, 检测限为10 pmol?L－1.

The Assembly,Hybridization and Detection of DNA on Gold Nanoparticles with Silver Enhancement

Authors report on the detection of DNA hybridization using electrochemistry method. The target ss-DNA was immobilized on glassy carbon electrode and hybridized with the gold nanoparticle-oligonucleotide DNA probe. A nanoparticle-promoted Ag precipitation was used to enlarge the nanoparticle tag, forming the Au/Ag core-shell structure, followed by the release of the silver metal atoms anchored on the hybrids by oxidative metal dissolution and the indirect determination of the solubilized Ag ions by anodic stripping voltammetry (ASV) at a carbon fiber microelectrode. Further signal amplification, and lowering of the detection limits to the picomolar domains, was achieved by precipitating silver. The results show that this method has good correlation for detection of DNA in the range of 100～1 000 pmol?L－1and allows detection at levels as low as 10 pmol?L－1 of the target oligonucleotides.