Raman spectroscopy (RS) is a modern scientific analytic fingerprint technique that detects, examines, and analyzes the constituent chemical composition of various substances (solid–liquid–gas and plasmons) through interaction of laser light with matter. It is intelligent to present qualitative and quantitative information about the sample’s chemical composition, polymorphism, phase, crystallinity, stress/strain, and contamination and impurity/defects. The key mechanism is profoundly based on the Raman principle that was originally named after and discovered by the Indian primer scientist C.V Raman, who won the Nobel prize after the exposure of the Raman effect [Raman 1916; Krishnan 1928]. This review briefly presents the physical origin of Raman scattering explaining the key classical and quantum mechanical concepts. Molecular variations of the Raman effect will also be considered, including resonance, coherent, and enhanced Raman scattering. Further, we discuss the molecular origins of prominent bands often found in the Raman spectra of SPR (surface plasmon resonance) samples. Finally, we examine the several active variations of Raman spectroscopy techniques in practice, looking at their applications, strengths, and challenges. This review is intended to be a starting resource for scientists new to Raman spectroscopy, providing theoretical background and practical examples as the foundation for further study and exploration of SPR and surface-enhanced Raman spectroscopy (SERS) techniques. While RS is now used in biology and medicine for novel pandemic diseases, Raman spectroscopy found its first applications in physics and chemistry and was mainly used to study vibrations and structure of molecules. One early factor limiting the implementation of RS was the weak scattering signal. Large intensities of monochromatic light are required to excite a detectable signal. This requirement became much easier to realize following the invention of the laser in 1960. Over the past decades, Raman spectroscopy has been prominently exploited better in biological applications, where it is able to detect and analyze DNA and RNA molecules. Generally, there are four main types of Raman spectroscopy, but the most feasible in biological field is the SERS. The noble metal nanoclusters play an important role for nanobiomedical and modern optical devices. The present review explored the single and bi-metallic (silver (Ag), copper (Cu), silver–copper (Ag–Cu), and copper–silver (Cu–Ag)) nanoclusters embedded in soda–lime glass that is prepared by ion-exchange method. The ion-exchanged glasses are annealed by different methods (furnace and laser). These samples exhibit surface plasmon and surface enhancement effect. Optical absorption spectroscopic analysis was done on the metal nanocluster composite glasses, and the spectra are well studied as a function of various post ion-exchange treatments and different sizes. As size effects are an essential aspect of nanomaterials, the effect of size on the optical absorption metal nanoclusters was studied using theoretical models and correlated with the experimental results. Formation of embedded bi-metallic nanoclusters is also achieved by furnace annealing or laser irradiation of the sequential Cu–Ag and Ag–Cu ion-exchanged samples. The formations of core–shell structures or alloying between the metal species were confirmed from the optical absorption spectra. This review analyzes the influence of different parameters (nanocluster size, morphology, and composition as well as surface plasmon resonance (SPR) wavelength) on SERS. Experimental study of SERS substrates consists of silver, copper, and alloyed copper–silver (Cu–Ag) or silver–copper (Ag–Cu) nanoclusters of various sizes and compositions with the aim of finding the optimal conditions for fabricating substrates with maximum SERS enhancement factors. The primary aim of this work is focused on the development of novel SERS-active substrates and their applications in various research fields. The basic principle is borrowing the rough feature from the supported under layer to produce the rough noble meal surface and achieve the surface enhancement effect. The prepared substrates meet the following requirements, such as stable, reproducible, possessing large enhancement factor, and easiness for preparation. SERS opens up exciting opportunities in the field of biophysical and biomedical spectroscopy, where it provides ultrasensitive detection and characterization of biophysically/biomedically relevant molecules and processes as well as a vibrational spectroscopy with extremely high spatial resolution. This review explains many fundamental features of SERS and then describes the use of embedded nanocluster for the fabrication of highly reproducible and robust SERS substrates. The present review discusses the synthesis of single and bi-metallic nanocomposite glasses by the commercial ion-exchange technique followed by the suitable thermal treatments like furnace and laser annealing. Post treatment, the samples were subjected to various studies like optical absorption and SERS, FESEM, photoluminescence, and grazing incidence X-ray diffraction.

拉曼光谱（RS）是一种现代科学分析指纹技术，通过激光与物质的相互作用来检测，检查和分析各种物质（固-液-气和等离激元）的化学组成。呈现有关样品的化学成分，多态性，相，结晶度，应力/应变以及污染和杂质/缺陷的定性和定量信息是明智的。关键机制深深地基于拉曼原理，该原理最初是由印度底漆科学家CV拉曼命名并发现的，拉曼在暴露拉曼效应后获得了诺贝尔奖[Raman 1916; 克里希南（1928）。本文简要介绍了拉曼散射的物理起源，解释了关键的经典和量子力学概念。拉曼效应的分子变化也将被考虑，包括共振，相干和增强的拉曼散射。此外，我们讨论了在SPR（表面等离振子共振）样品的拉曼光谱中经常发现的显着谱带的分子起源。最后，我们考察了拉曼光谱技术在实践中的几种活跃变化，并探讨了它们的应用，优势和挑战。这篇综述旨在为拉曼光谱学的新手提供一个入门资源，提供理论背景和实际示例，为进一步研究和探索SPR和表面增强拉曼光谱（SERS）技术奠定基础。尽管RS现在已用于新型大流行疾病的生物学和医学领域，拉曼光谱法在物理和化学领域首次发现了应用，主要用于研究分子的振动和结构。限制RS实施的一个早期因素是弱散射信号。需要大强度的单色光来激发可检测的信号。随着1960年激光器的发明，这一要求变得更加容易实现。在过去的几十年中，拉曼光谱法在生物学应用中得到了显着的发展，可以检测和分析DNA和RNA分子。通常，拉曼光谱有四种主要类型，但在生物领域中最可行的是SERS。贵金属纳米簇在纳米生物医学和现代光学设备中起着重要作用。本综述探讨了单金属和双金属（银（Ag），嵌入离子交换法制得的钠钙玻璃中的铜（Cu），银铜（Ag-Cu）和铜-银（Cu-Ag）纳米团簇。离子交换玻璃通过不同的方法（熔炉和激光）进行退火。这些样品表现出表面等离子体激元和表面增强作用。在金属纳米团簇复合玻璃上进行了光吸收光谱分析，并且根据各种离子交换后处理和不同尺寸对光谱进行了很好的研究。由于尺寸效应是纳米材料的重要方面，因此使用理论模型研究了尺寸对光吸收金属纳米团簇的影响，并将其与实验结果相关联。嵌入的双金属纳米簇的形成也可以通过对连续的Cu-Ag和Ag-Cu离子交换样品进行炉内退火或激光辐照来实现。从光吸收光谱证实了核-壳结构的形成或金属物质之间的合金化。这篇综述分析了不同参数（纳米簇的大小，形态，组成以及表面等离振子共振（SPR）波长）对SERS的影响。SERS基底的实验研究包括银，铜以及各种尺寸和成分的合金铜-银（Cu-Ag）或银铜（Ag-Cu）纳米团簇，目的是寻找制造具有最大SERS的基底的最佳条件增强因素。这项工作的主要目的是致力于新型SERS活性底物的开发及其在各个研究领域中的应用。基本原理是从被支撑的底层借用粗糙的特征，以产生粗糙的高贵金属粉表面并达到表面增强效果。所制备的底物满足以下要求，例如稳定，可再现，具有大的增强因子以及易于制备。SERS在生物物理和生物医学光谱学领域提供了令人兴奋的机遇，它提供了对生物物理/生物医学相关分子和过程的超灵敏检测和表征，以及具有极高空间分辨率的振动光谱学。这篇综述解释了SERS的许多基本特征，然后描述了嵌入式纳米簇在制备高度可复制且坚固的SERS基底中的用途。本综述讨论了通过商业化的离子交换技术合成单金属和双金属纳米复合玻璃，然后采用合适的热处理方法，如熔炉和激光退火。处理后，对样品进行了各种研究，例如光吸收和SERS，FESEM，光致发光和掠入射X射线衍射。