Key Laboratory of Drug Prevention and Control Technology of Zhejiang Province, Zhejiang Police College, 555 Binwen Road, Binjiang District, Hangzhou 310053, China.
Key Laboratory of Drug Control and Monitoring, National Anti-Drug Laboratory Zhejiang Regional Center, 555 Binwen Road, Binjiang District, Hangzhou 310053, China.
Molecules. 2022 Jun 20;27(12):3939. doi: 10.3390/molecules27123939.
Porous noble metal nanomaterials have attracted extensive attention due to their high specific surface area and surface plasmon resonance effect. However, it is difficult to form porous structures due to the high mobility and low reduction potential of noble metal precursors. In this article, we developed a facile method for preparing porous Ag with a controllable structure at room temperature. Two kinds of Ag crystals with different porous structures were successfully prepared by using AgCl cubes as sacrificial templates. Through the galvanic replacement reaction of Zn and AgCl, Ag crystals with a sponge-like porous structure were successfully prepared. Additionally, using NaBH as the reducing agent, we prepared granular porous Ag cubes by optimizing the amount of reducing agent. Both the sponge-like and granular porous Ag cubes have clean and accessible surfaces. In addition, we used the prepared two porous Ag cubes as substrate materials for SERS detection of five kinds of methamphetamine analogs. The experimental results show that the enhancement effect of granular porous Ag is better than that of sponge-like porous Ag. Furthermore, we probed the hot spot distribution of granular porous Ag by Raman mapping. By using granular porous Ag as the substrate material, we have achieved trace detection of 5 kinds of methamphetamine analogs including Ephedrine, Amphetamine, N-Methyl-1-(benzofuran-5-yl)propan-2-amine (5-MAPB), N-Methyl-1-(4-methoxyphenyl)propan-2-amine (PMMA) and N-Methyl-1-(4-fluorophenyl)propan-2-amine (4-FMA). Furthermore, to achieve qualitative differentiation of analogs with similar structures we performed density functional theoretical (DFT) calculations on the Raman spectra of the above analogs. The DFT calculations provided the vibrational frequencies, Raman activities, and normal mode assignment for each analog, enabling the qualitative differentiation of the above analogs.
多孔贵金属纳米材料因其具有高比表面积和表面等离子体共振效应而受到广泛关注。然而，由于贵金属前体的高迁移率和低还原电位，很难形成多孔结构。在本文中，我们开发了一种在室温下制备具有可控结构的多孔 Ag 的简便方法。通过使用 AgCl 立方体作为牺牲模板，成功制备了两种具有不同多孔结构的 Ag 晶体。通过 Zn 和 AgCl 的电置换反应，成功制备了具有海绵状多孔结构的 Ag 晶体。此外，通过优化还原剂 NaBH4 的用量，我们制备了颗粒状多孔 Ag 立方体。海绵状和颗粒状多孔 Ag 立方体都具有清洁和可接近的表面。此外，我们使用制备的两种多孔 Ag 立方体作为基底材料，用于五种苯丙胺类似物的 SERS 检测。实验结果表明，颗粒状多孔 Ag 的增强效果优于海绵状多孔 Ag。此外，我们通过拉曼映射探测了颗粒状多孔 Ag 的热点分布。通过使用颗粒状多孔 Ag 作为基底材料，我们实现了对 5 种苯丙胺类似物包括麻黄碱、苯丙胺、N-甲基-1-(苯并呋喃-5-基)丙-2-胺（5-MAPB）、N-甲基-1-(4-甲氧基苯基)丙-2-胺（PMMA）和 N-甲基-1-(4-氟苯基)丙-2-胺（4-FMA）的痕量检测。此外，为了实现对结构相似的类似物的定性区分，我们对上述类似物的拉曼光谱进行了密度泛函理论（DFT）计算。DFT 计算提供了每个类似物的振动频率、拉曼活性和正则模式分配，从而能够对上述类似物进行定性区分。
