Daniel Salman, Matikainen Antti, Turunen Jari, Vahimaa Pasi, Nuutinen Tarmo
Institute of Photonics, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland.
Institute of Photonics, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland.
J Colloid Interface Sci. 2015 Jan 1;437:119-123. doi: 10.1016/j.jcis.2014.09.037. Epub 2014 Sep 28.
Surface Enhanced Raman Scattering (SERS) is gaining popularity among analytical methods in biosciences and sensor technology since it provides high specificity, non-destructiveness, and the unique fingerprint spectra of the molecules. Historically, glass has been the primary choice as a substrate for SERS, but polymers are attractive due to their plasticity, ease of handling, and their low cost. Herein, the performance of cyclo olefin polymer (COP) as a substrate with 1D subwavelength modulations combined with silver nanoparticles is studied for SERS measurements. These 1D grating structures on polymer are fabricated by hot embossing method followed by deposition of silver nanoparticles (AgNPs) using the drop-casting method. Spatial variations of the substrate surface have been reduced by providing a consistent distribution of hot-spots. We present an analysis of the surface uniformity related to the distribution of Ag particles. We achieve around 8-fold Raman signal enhancements with improved reproducibility in comparison to smooth, unmodulated surfaces with AgNPs. This method of fabrication of SERS substrates is simple and inexpensive compared to the thermal evaporation method (TEM) of metallic layer deposition. It also helps to control the tarnishing effect on metallic surfaces due to silver deposition prior to Raman measurements. This kind of polymer gratings combined with AgNPs have potential applications in medical, biological and chemical sensing, where Raman signal enhancement with high reproducibility is required.
表面增强拉曼散射（SERS）在生物科学和传感器技术的分析方法中越来越受欢迎，因为它具有高特异性、非破坏性以及分子独特的指纹光谱。从历史上看，玻璃一直是SERS基底的主要选择，但聚合物因其可塑性、易于处理和低成本而具有吸引力。在此，研究了环烯烃聚合物（COP）作为具有一维亚波长调制并结合银纳米颗粒的基底用于SERS测量的性能。聚合物上的这些一维光栅结构通过热压印法制造，然后使用滴铸法沉积银纳米颗粒（AgNPs）。通过提供一致的热点分布，减少了基底表面的空间变化。我们对与Ag颗粒分布相关的表面均匀性进行了分析。与具有AgNPs的光滑、未调制表面相比，我们实现了约8倍的拉曼信号增强，且重现性得到改善。与金属层沉积的热蒸发法（TEM）相比，这种SERS基底的制造方法简单且成本低廉。它还有助于控制拉曼测量前由于银沉积对金属表面产生的 tarnishing 效应。这种结合了AgNPs的聚合物光栅在医疗、生物和化学传感领域具有潜在应用，这些领域需要具有高重现性的拉曼信号增强。
