Surface-enhanced Raman scattering (SERS) is a very promising detection/diagnostic technique at trace levels as the molecules exhibit a significant increase in their Raman signals when they are attached or are in proximity to plasmonic structures. In this study, a numerical design of SERS substrate as a probe has been demonstrated for detection and diagnosis of blood, water and urea samples. The proposed nanospiral design is polarization independent, and it offers the enhancement of the electric field strength ~ 10⁹. The substrate design is based on 3D finite difference time domain simulations and is robust, versatile and sensitive even at low concentrations of the analyte. It works equally well when used in the reflection mode. In this study, the cavity quantum electrodynamics (CQED) Purcell factor has also been transposed to plasmonics. The Purcell factor in corroboration with CQED has been used to achieve efficient light–matter interaction at nanoscale by providing a more realistic result. It takes into account the randomness of incident wave polarizations and arbitrary orientations of interacting molecules. This gives a deeper insight into electromagnetic Raman gain in SERS and can be used to design novel SERS substrates.

表面增强拉曼散射（SERS）在痕量水平上是一种非常有前途的检测/诊断技术，因为当分子附着或接近等离子体结构时，它们的拉曼信号会显着增加。在这项研究中，已经证明了用于检测和诊断血液，水和尿素样品的SERS底物作为探针的数值设计。拟议的纳米螺旋设计是偏振无关的，它可以增强电场强度〜10 ⁹。底物设计基于3D时域有限差分仿真，即使在低浓度的分析物下也具有坚固，通用和灵敏的特点。在反射模式下使用时，效果也一样好。在这项研究中，腔量子电动力学（CQED）Purcell因子也已经转换为等离子体。通过提供更真实的结果，已将赛尔因子与CQED进行了佐证，从而在纳米级实现了有效的光-物质相互作用。它考虑了入射波极化的随机性和相互作用分子的任意方向。这可以更深入地了解SERS中的电磁拉曼增益，并可用于设计新颖的SERS基板。