For sensitive and reproducible surface-enhanced Raman scattering (SERS)-based trace detection, a SERS platform with high concentration of homogeneously distributed hotspots is needed. Herein, we report a facile monolayer assembly of multispiked gold nanoparticles (MSGNPs) of various sizes over a large area. The assembly was achieved simply by tuning the concentration of MSGNPs in a suspension and subsequently drying it on a substrate under ambient conditions. A monolayer assembly for MSGNP sizes ranging from 150 to 640 nm has been demonstrated. The MSGNP assembly showed excellent sensitivity and uniformity of SERS-based trace detection, owing to the presence of high concentration of uniformly distributed interparticle and intraparticle hotspots. In particular, detection of 10 fM of a toxic dye, crystal violet, has been demonstrated. Moreover, ammonium nitrate, which is a commonly used material for homemade explosives, was detected at 1 μM level. The MSGNP-based SERS platforms have great potential for applications in sensitive and reliable toxin and explosive detection.

中文翻译：

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基于表面增强拉曼光谱的染料和炸药痕量检测的多掺金纳米粒子的单层组装。

对于灵敏且可重现的基于表面增强拉曼散射（SERS）的痕量检测，需要具有高浓度均匀分布热点的SERS平台。在这里，我们报告了大面积上各种大小的多掺金纳米颗粒（MSGNPs）的简便单层组件。通过调节悬浮液中MSGNP的浓度，然后在环境条件下将其在基材上干燥，即可轻松完成组装。已经证明了MSGNP尺寸为150到640 nm的单层组件。由于存在高浓度的均匀分布的粒子间和粒子内热点，MSGNP组件显示出出色的灵敏度和基于SERS的痕量检测的均匀性。特别是，已证明检测到10 fM的有毒染料结晶紫。此外，硝酸铵是自制炸药的常用材料，检测到的浓度为1μM。基于MSGNP的SERS平台在灵敏可靠的毒素和爆炸物检测中具有广阔的应用前景。