利用聚碳酸酯模板制备的金纳米棒的表面增强Raman散射效应研究

Surface-enhanced Raman scattering effects of gold nanorods prepared by polycarbonate membranes

采用聚碳酸酯模板和电化学沉积法制备基于金纳米棒的Raman场增强衬底,制备的金纳米棒直径大约36nm,长约1μm,测试结果显示其共振吸收峰的位置约为540nm.比较了谐振和非谐振条件下的场增强情况,并确定了场增益系数,结果显示谐振激光激发下的增益比非谐振情况下提高了7.36倍.本研究相对于前人的工作取得了如下进展:一是讨论了谐振模式与非谐振模式下的金纳米棒的场增益系数,利用谐振波长的激光激发金纳米棒,进一步提高了场增益;二是消除了聚碳酸酯模板分子的荧光背底,使其在表面增强Raman散射方面的应用进一步变得可行.

Using a polycarbonate membrane （PCM） as a template, and combining with the electrochemical deposition method, we prepare gold nanorods each with about 36 nm in diameter and 1 μm in length. We measure transmission spectra, and find that the resonant absorption peak is at around 540 nm. Subsequently, the enhancement effects of the nanorods are investigated with 514 nm and 633 nm laser excitations. Comparing the spectra under resonant condition with those under non-resonant condition, we conclude that the field enhancement effect under the resonant excitation is more prominent than under the non-resonant excitation. The enhancement factor under the resonant excitation is increased to 7 times of the factor under the non-resonant excitation. Comparing with similar researches, we achieve the following two improvements： 1） with a resonant excitation, we significantly increase the enhancement factor of gold nanorods; 2） we eliminate the fluorescence of PCM molecules, thus make the template method more feasible for transparent surface-enhanced Raman scattering substrate applications.