Surface-enhanced Raman spectroscopy (SERS) with high-sensitivity performance is a very necessary detection technology. Here, we present a method for increasing the performance of SERS based on silver triangular nanoprism arrays (ATNAs) vertically excited via a focused azimuthal vector beam (AVB). The ATNA substrates with different structural parameters are prepared based on the traditional self-assembled and modified film lift-off technique. Based on a theoretical model established adopting the structural parameters of the ATNA substrates, theoretical simulation results show that AVB excitation can achieve greater electric-field enhancement than linearly polarized beam (LPB) excitation. Experimental result indicates that SERS sensitivity obtained via AVB excitation is 10−13 M (1 M = 1 mol/L) using rhodamine 6G (R6G) as the target analyte, which is 2 orders of magnitude lower than that of LPB excitation (10−11 M). Meanwhile, the uniformity and reproducibility of the ATNA substrates are examined using Raman mapping and batch-to-batch measurement, respectively, and the Raman enhancement factor is calculated to be ∼3.3×107. This method of vector light field excitation may be used to improve the SERS performance of the substrates in fields of ultra-sensitive Raman detection.

中文翻译：

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方位矢量束激发银三角纳米棱镜以提高表面增强拉曼光谱的性能

具有高灵敏度性能的表面增强拉曼光谱（SERS）是一项非常必要的检测技术。在这里，我们提出了一种基于通过聚焦方位矢量束 (AVB) 垂直激发的银三角纳米棱镜阵列 (ATNA) 来提高 SERS 性能的方法。基于传统的自组装和改性薄膜剥离技术制备了具有不同结构参数的 ATNA 基板。基于采用ATNA基板结构参数建立的理论模型，理论仿真结果表明，AVB激励比线偏振光束（LPB）激励可以实现更大的电场增强。实验结果表明，使用罗丹明 6G (R6G) 作为目标分析物，通过 AVB 激发获得的 SERS 灵敏度为 10-13 M (1 M = 1 mol/L)，这比 LPB 激励 (10-11 M) 低 2 个数量级。同时，分别使用拉曼映射和批次间测量来检查 ATNA 基板的均匀性和再现性，计算出拉曼增强因子为~3.3×107。这种矢量光场激发方法可用于提高超灵敏拉曼检测领域中基板的SERS性能。