The Preparation Of Nanoscale Golden Surface Of SERS Substrate By Pulsed Laser And The Application In Raman Spectroscopy

Raman spectrum using photon as probe is a vibrating spectrum related directly to the molecular structure, which is known as the fingerprint spectrum of material structures. Any tiny changes of structures can be sensitively reflected in Raman spectrum; therefore, it is widely used in physics, chemistry, biology and law fields of molecular structure, quality control, archaeology and so on. The developments of surface enhanced Raman Scattering (SERS) technique greatly enhance signal sensitivity, making the Raman technique as photon probe.SERS substrates usually include rough metal surface and noble metal colloid, which could be prepared by chemical way, such as oxidation-reduction, or physical way, laser ablation. The chemical way is simple and easy to obtain metal colloid with high efficiency of SERS effect. However, the residual in the chemical colloid brings problem for using and analyzing the SERS signal, while it is very pure but hard to obtain abundant metal colloid in laser ablation method. There are also other methods for preparing rough surface, such as modified electrode, mechanically polished metal surfaces and vacuum evaporated metal surfaces. But these methods also have many disadvantages, including the residual impurity, hard to control the rough scale and so on. We hope to find a new method, which is simple, easy to control, pure, inexpensive and widely used, to prepare SERS substrate. Thus the laser ablation method is chosen by us to prepare rough surface for SERS.In this paper, we have studied the SERS spectroscopy of probe molecules of Fullerence (C60, C70), SWNT and BHb when the rough surface prepared by laser ablation method is used, since the Raman spectroscopy could reflect abundant relative molecular structure-information and component information. Based on the rough surface by laser ablation, we have obtained high quality of SERS spectroscopy and studied the adsorption behavior of molecular on substrate and enhancement mechanism.In this paper, we obtained more sensitive, better resolving power and high efficient SERS active system by rough golden surface in laser ablation method, which is not only bringing a much bigger Raman scattering section, but also showing us SERS signal of high intensity, high sensitivity and high resolving power for the special shapes of rough surface, with double enhancement mechanism of normal rough surface and colloid. The laser ablation method afford new subject and experiment basis for further discussion of SERS enhancement mechanism since it is simple, easy to control, steady and pure.