【摘要】 表面增强拉曼散射(SERS)以其无损、超灵敏、快速检测分析等优点而备受关注,在化学和生物传感等应用领域有着极大的潜力。研制灵敏度高、重复性强、稳定性好的SERS基底,对于实现其在痕量分析、生物诊断中的实际应用具有重要意义。具有微/纳米结构的聚合物具有优异的机械性能、光学性能、耐化学性等优点。通过模板压印法,利用多孔阳极氧化铝(AAO)在聚合物聚碳酸酯(PC)表面制备一种高度有序的纳米PC尖锥阵列结构,然后通过蒸发镀膜在PC尖锥阵列上沉积一层银膜,制备了大面积Ag纳米颗粒修饰的高度有序聚合物纳米尖锥阵列。高曲率纳米针状结构顶端的银颗粒及颗粒之间狭小的纳米间隙能产生大量的SERS"热点"。这种方法得到了均匀,可重复,大面积高增强的SERS活性基底,并进一步研究了不同沉积厚度银膜的SERS特性。用扫描电子显微镜(SEM)对其进行了表征,以结晶紫作为探针分子对这种结构进行研究。结果表明:拉曼信号强度随银厚度的增加显示为先增强后减弱的趋势。基底对结晶紫的拉曼增强因子达到5.4×10~6,基底主要拉曼峰强度的RSD为10%,说明该基底具有很好的检测灵敏性和重复性。此外,基底在存放40 d后,在相同条件下仍然保持着高SERS性能,表现出很好的稳定性。整个制备过程简单易行,重复性好,制作成本非常低廉,而且能够规模化制备,可方便地作为活性基底应用于SERS研究,必将具有广阔的研究和应用前景。更多还原

【Abstract】 Recently, Surface Enhanced Raman Scattering(SERS) has attracted much attention due to its advantages innondestructive, ultra-sensitive and rapid detection analysis. It has great potential in chemical and biological sensing applications. SERS substrates with high sensitivity, repeatability and stability are of great significance to the application in trace analysis and biological diagnosis. Polymer materials with micro/nanostructure have excellent mechanical and optical properties and chemical resistance. In this work, a highly ordered polycarbonate(PC) nanocone array was fabricated by template imprinting on the surface of PC using porous anodic alumina(AAO). Then a silver film was deposited on the nanocone array by thermal evaporation technology, and alarge area of ordered polymer nanocone array modified by Ag nanoparticles was prepared. A large number of SRES "hot spots" can be generated by the narrow nano-gap between silver particles and particles at the top of the high curvature nano-needle structure. SERS active substrates with uniform, repeatable, large area and high enhancement were obtained by this method. The SERS characteristics of silver films with different thickness were further studied. Scanning electron microscopy(SEM) was used to characterize the structure. Crystal violet was used as a probe molecule in this study. The results show that the intensity of Raman signal increases first and then decreases with the increase of silver thickness. The Raman enhancement factor is of ～5.4×10~6, and the RSD of the main Raman peak intensity of CV is 10%, indicating good sensitivity and repeatability. In addition, after 40 days storage, the substrate still maintained high SERS performance under the same conditions, showing good stability. The whole preparation process is simple, reproducible, very cheap, and can be prepared on a large scale. It can be easily used as an active substrate for SERS research, and will have broad research and application prospects.更多还原