Li Lujie, Zhang Tingting, Zhang Lan, Wang Gongying, Huang Xianhuai, Li Weihua, Wang Lingling, Li Yan, Li Jiansheng, Lu Rui
School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
School of Environment and Energy Engineering, Anhui Provincial Key Laboratory of Environmental Pollution Control and Resource Reuse, Anhui Jianzhu University, Hefei, 230022, China.
Anal Chim Acta. 2024 Dec 1;1331:343330. doi: 10.1016/j.aca.2024.343330. Epub 2024 Oct 10.
It is well established that surface-enhanced Raman scattering (SERS) is one of the most commonly used spectral analysis techniques in real-world applications, including chemical and biological sensing, analytical detection, and even forensics. It offers high sensitivity, high resistance to solvents, photobleaching, and limited spectrum bands. In general, SERS is caused by two mechanisms, the electromagnetic enhancement mechanism (EM) and the chemical enhancement mechanism (CM), although the exact mechanism is not yet known. For increased sensitivity, a SERS substrate based on EM coupled with CM is essential.
Using electrostatic self-assembly, we fabricated many homogeneous hot spots for the substrate by evenly mixing positive charge Ag nanoparticles (AgNPs) with negative charge TiCT. In addition, there is a clearly enhanced effect due to the high affinity between the tested molecule and TiCT, which facilitates molecule-to-molecule charge transfer. After successfully preparing the TiCT/AgNPs substrate, the R6G dye molecule was used to investigate its SERS activity. According to the results, the substrate can reach an enhancement factor of 3.8 × 10. Furthermore, it has been demonstrated that the coupling effect between EM and CM is the main reason for the excellent performance of the TiCT/AgNPs composite substrate. Based upon the results of detecting the two biomarkers, adenosine triphosphate and folic acid, the detection limits were determined to be 4.27 × 10 M and 7.26 × 10 M, respectively.
Two-dimensional metal carbide TiCT material can be used to obtain CM in surface Raman scattering. It has been demonstrated that the combination of CM and EM with nano-precious metals can produce an extremely sensitive SERS substrate that is dependable and stable. Additionally, the TiCT/AgNPs study offers a novel perspective for the advancement of the SERS coupling mechanism in addition to providing direction for realistic detection.
众所周知，表面增强拉曼散射（SERS）是实际应用中最常用的光谱分析技术之一，包括化学和生物传感、分析检测甚至法医学。它具有高灵敏度、高耐溶剂性、抗光漂白性以及有限的光谱带。一般来说，SERS由两种机制引起，即电磁增强机制（EM）和化学增强机制（CM），尽管确切机制尚不清楚。为了提高灵敏度，基于EM与CM耦合的SERS基底至关重要。
利用静电自组装，通过将带正电荷的银纳米颗粒（AgNPs）与带负电荷的TiCT均匀混合，为基底制造了许多均匀的热点。此外，由于被测分子与TiCT之间的高亲和力，存在明显的增强效应，这有利于分子间的电荷转移。成功制备TiCT/AgNPs基底后，使用R6G染料分子研究其SERS活性。结果表明，该基底的增强因子可达3.8×10。此外，已证明EM和CM之间的耦合效应是TiCT/AgNPs复合基底优异性能的主要原因。基于对两种生物标志物三磷酸腺苷和叶酸的检测结果，确定检测限分别为4.27×10 M和7.26×10 M。
二维金属碳化物TiCT材料可用于在表面拉曼散射中获得CM。已证明CM与EM与纳米贵金属的结合可产生极其灵敏、可靠且稳定的SERS基底。此外，TiCT/AgNPs研究除了为实际检测提供方向外，还为SERS耦合机制的发展提供了新的视角。
