基于分子间裂分G-四链体-氯化血红素DNA酶自组装纳米线的“Turn-on”型汞离子传感研究

以聚苯乙烯微球为载体,利用杂交链式反应,发展了一种基于T-Hg^(2+)-T特异性识别及串联分子间裂分G-四链体-血红素DNA酶纳米线催化信号放大的Hg^(2+)"Turn on"型高灵敏生物传感器。当汞离子存在时,"T-Hg^(2+)-T"特殊结构的形成促使微球表面修饰的富T探针打开并捕获设计的发夹探针P1,由此引发与发夹探针P2之间的杂交链式反应。由于P1、P2的5'游离末端及3'游离末端都包含富G序列,通过杂交链式反应相互拉近并串联排列,在微球表面折叠形成包含串联分子间裂分G-四链体-血红素DNA酶的自组装DNA纳米线。在最优实验条件下,传感器对Hg^(2+)的线性检测范围为2 pmol/L～1 nmol/L,检出限为1.5 pmol/L;当试样中的共存离子大量存在时,传感器对Hg^(2+)仍然具有高的选择性。此方法检测Hg^(2+)具有良好的选择性、灵敏度及稳定性。

Fabrication of Highly Conductive Pd Nanowires using PDMS Transfer Method on DNA Scaffolds through Ethanol-Reduction

We have developed a simple, productive, and ettectlve poly（cllmetnysltoxane） rranu fer method to fabricate highly conductive Pd nanowires following DNA scaffolds on various substrates, based on ethanolreduction at low temperature. Pd nanoparticles were selectively deposited and confined onto the DNA templates on a PDMS sheet to form Pd nanowires and then the nanowires were transferred to other various substrates with a low occurrence of par asitic nanoparticles. The structure, morphology and the conductance of Pd nanowires were characterized with transmission electron microscopy, field emission scanning electron mi croscopy, and electrical transport measurement, respectively. Moreover, the growth process of the Pd nanowires was investigated by varying the incubation time and reaction temper ature. The present strategy provides a new method to fabricate extremely dense, highly conductive, and well aligned Pd nanowires on various substrates, which make it promising for building nanosensors and nanoelectronic devices.