Preparation and modification of metal nano-contacts Photo-excitation

我们开发了一种新的技术，通过结合光照射和外加电场的影响来控制尺寸范围小于几十纳米的金属结构。金属纳米结构的一个有前途的应用是利用表面增强和拉曼散射（SERS）进行单分子检测。虽然一些复杂的方法在产生完全可重复的SERS活性方面是成功的，但由于需要专门的合成或制备技术，制备通常是复杂的。需要开发新的简便可控的SERS活性底物制备技术。在这项研究中，我们的技术控制金属纳米结构在玻璃基板上制备了具有很强SERS信号的薄膜。在控制溶液中电化学电位的条件下，制备了可持续的金属纳米触点。采用电化学刻蚀或沉积的方法，在溶液中可持续的细金线间隙处制备了Cu、Ag、Ni、Pd、Pb等金属纳米触点。室温下，Cu、Ag、Ni和Pd接触处的电导量子化表现出相对稳定的单位值行为。与其他金属相比，铅接触的电导量化行为相当不稳定。通过控制电化学电位，考察了金纳米接触在含ClO_<4->、S0_4^<2->、Cl^-等不同离子溶液中的力学稳定性。

We have developed novel techniques to control metal structures in the size range less than a few tens nm by combing the effects of photo-irradiation and applying an external electric field. One of the promising applications of metal nanostructures is for single molecular detection employing surface enhanced & Raman scattering (SERS). Although several sophisticated methods were successful with respect to generation of fully reproducible SERS activity, the preparations were often complicated due to the need for specialized synthetic or preparative techniques. Novel facile and controllable techniques to prepare SERS active substrates should be developed. In this study, our technique to control metal nanostructure on glass substrate was used to prepare the films showing very strong SERS signal. Sustainable metal nanocontacts were fabricated under controlled electrochemical potential in solution.Metal nanocontacts of Cu, Ag, Ni, Pd, and Pb were fabricated via the electrochemical etching or deposition method at a gap of sustainable thin Au wires in solution. Relatively stable behaviors of the conductance quantization exhibiting a unit value were apparent at the contacts of Cu, Ag, Ni, and Pd at room temperature. Conductance quantization behavior of the Pb contact was rather unstable in comparison with other metals. echanical stability of Au nanocontact was also examined by controlling electrochemical potential in various solution containing ClO_<4->, S0_4^<2->, Cl^-ions.