Chauvin Adrien, Lafuente Marta, Mevellec Jean Yves, Mallada Reyes, Humbert Bernard, Pina Maria Pilar, Tessier Pierre-Yves, El Mel Abdelaziz
Institut des Matériaux Jean Rouxel, IMN, Université de Nantes, CNRS, 2 rue de la Houssinière B.P. 32229, 44322 Nantes cedex 3, France.
Nanoscale. 2020 Jun 21;12(23):12602-12612. doi: 10.1039/d0nr01721c. Epub 2020 Jun 5.
Lamellar nanoporous gold thin films, constituted of a stack of very thin layers of porous gold, are synthesized by chemical etching from a stack of successively deposited nanolayers of copper and gold. The gold ligament size, the pore size and the distance between lamellas are tunable in the few tens nanometer range by controlling the initial thickness of the layers and the etching time. The SERS activity of these lamellar porous gold films is characterized by their SERS responses after adsorption of probe bipyridine and naphtalenethiol molecules. The SERS signal is investigated as a function of the bipyridine concentration from 10 mol L to 10 mol L. The higher SERS response corresponds to an experimental detection limit down to 10 mol L. These performance is mainly attributed to the specific nanoporous gold architecture and the larger accessible surface to volume ratio. The lamellar nanoporous gold substrate is explored for sensitive SERS detection of dimethyl methylphosphonate (DMMP), a surrogate molecule of the highly toxic G-series nerve agents. The resultant nanostructure facilitates the diffusion of target molecules through the nanopores and their localization at the enhancing metallic surface leading to the unequivocal Raman signature of DMMP at a concentration of 5 parts per million.
层状纳米多孔金薄膜由一叠非常薄的多孔金层构成，通过对一叠依次沉积的铜和金纳米层进行化学蚀刻来合成。通过控制层的初始厚度和蚀刻时间，金韧带尺寸、孔径和薄片之间的距离可在几十纳米范围内调节。这些层状多孔金薄膜的表面增强拉曼散射（SERS）活性通过吸附探针联吡啶和萘硫醇分子后的SERS响应来表征。研究了SERS信号作为联吡啶浓度从10⁻⁶mol/L到10⁻¹²mol/L的函数。较高的SERS响应对应于低至10⁻¹²mol/L的实验检测限。这些性能主要归因于特定的纳米多孔金结构和较大的可及表面积与体积比。探索了层状纳米多孔金基底用于对高毒性G系列神经毒剂的替代分子甲基膦酸二甲酯（DMMP）进行灵敏的SERS检测。所得纳米结构促进了目标分子通过纳米孔的扩散及其在增强金属表面的定位，从而在百万分之五的浓度下产生了明确的DMMP拉曼特征峰。
