Abstract Flexible Surface-Enhanced Raman Spectroscopy (SERS) substrates based on silver nanoparticles (AgNP) immobilized in agar gels have been developed to detect cocaine in $ 100 Argentinian banknotes by SERS spectroscopy. The AgNP were characterized by absorption spectroscopy and Scanning Transmition Electron Microscopy (STEM). The SERS substrates were first evaluated using a probe molecule, methylene blue (MB), with well-known SERS activity. The achieved limit of detection (LOD) was ∼3 pg.cm−2 (∼60 molecules/spot). SERS experiments with cocaine hydrochloride were performed using these substrates; the LOD achieved was ∼70 ng.cm−2 (0.7 fg/spot). Cocaine was detected on intentionally contaminated $ 100 Argentinian banknotes. Finally, the analysis of 10 banknotes in circulation (one of which was intentionally contaminated as a blind test) resulted in the detection of cocaine in two of the banknotes analysed.

中文翻译：

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SERS检测阿根廷钞票中可卡因的研究

摘要 基于固定在琼脂凝胶中的银纳米粒子 (AgNP) 的柔性表面增强拉曼光谱 (SERS) 基底已开发用于通过 SERS 光谱检测 100 美元阿根廷钞票中的可卡因。AgNP 通过吸收光谱和扫描透射电子显微镜 (STEM) 进行表征。首先使用具有众所周知的 SERS 活性的探针分子亚甲蓝 (MB) 评估 SERS 底物。达到的检测限 (LOD) 为~3 pg.cm-2（~60 个分子/点）。使用这些底物进行了盐酸可卡因的 SERS 实验；达到的 LOD 约为 70 ng.cm-2 (0.7 fg/spot)。在故意污染的 100 美元阿根廷钞票上检测到可卡因。最后，