Tips of noble metal nanostructures and the gaps between closely packed noble metal nanostructures are widely claimed as hot-spots for SERS sensing. A significant amount of effort and expertise has been devoted to the reformation and maximum utilization of the “tips” and “gaps”. However, most studies focus on the “tips” or the “gaps” separately. Here we report a novel SERS substrate that contains a particular mesh structure of curved-edge gold nanocubes (CENCs) and Au nanospheres (Au NSs), one of the tips of CENCs inserted into the gaps between three closely packed Au NSs. Meanwhile, a facile and time-saving novel protocol has been proposed to fabricate this mesh structure in the form of a bilayer SERS substrate. The as-fabricated substrate exhibited extraordinary SERS sensitivity for malachite green (MG) and melamine, which could be attributed to the tip–gap mesh structure. The detection limit is as low as 10⁻¹² M and 10⁻⁹ M, respectively.

中文翻译：

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尖端间隙的网状双层SERS底物，可实现高灵敏度检测†

广泛声称贵金属纳米结构的尖端和紧密堆积的贵金属纳米结构之间的间隙是SERS传感的热点。在“技巧”和“空白”的改革和最大程度的利用上投入了大量的精力和专业知识。但是，大多数研究分别关注“技巧”或“空白”。在这里，我们报告了一种新型的SERS基底，其中包含弯曲边缘金纳米立方体（CENCs）和金纳米球（Au NSs）的特殊网状结构，CENC的尖端之一插入了三个紧密堆积的Au NSs之间的缝隙中。同时，已经提出了一种简便且节省时间的新颖协议来以双层SERS衬底的形式来制造该网状结构。加工后的基材对孔雀石绿（MG）和三聚氰胺表现出非凡的SERS敏感性，这可以归因于尖端间隙网格结构。检出限低至10^分别为-12 M和10 ^-9M。