Surface-enhanced Raman scattering (SERS) has undergone an important development in the detection and identification of extremely low traces of explosives over the past few years. Here we fabricated a new type of three-dimensional (3D) SERS sensors by loading AuNR@AgNCs on bacterial cellulose aerogels for the detection of 2, 4, 6-trinitrotoluene (TNT). The aerogel substrates with hierarchical pore structure are favored by the construction of dense 3D hot-spot distribution and the enrichment of TNT molecules. The retention aid of polyethyleneimine was used to improve the loading capacity as well as prevent the aggregation of nanoparticles. Moreover, AuNR@AgNCs were modified with p-aminobenzenethiol to improve the affinity of SERS substrates to TNT via the formation of Meisenheimer complex. Owing to the unique structure and morphology of AuNR@AgNCs, the composite SERS substrate can detect trace TNT with a limit of detection of 8 × 10⁻¹² g/L and the SERS enhancement factor is high up to 1.87 × 10⁸.

在过去的几年中，表面增强拉曼散射（SERS）在检测和识别极低痕量的爆炸物方面经历了重要的发展。在这里，我们通过在细菌纤维素气凝胶上加载AuNR @ AgNCs来检测2、4、6-三硝基甲苯（TNT），从而制造了新型的三维（3D）SERS传感器。具有分层孔结构的气凝胶基质受稠密3D热点分布的构造和TNT分子富集的青睐。聚乙烯亚胺的助留剂用于改善载量并防止纳米颗粒聚集。此外，用p修饰了AuNR @ AgNCs-氨基苯硫醇通过形成Meisenheimer配合物来提高SERS底物对TNT的亲和力。由于AuNR @ AgNCs的独特结构和形态，复合SERS底物可检测痕量TNT，检出限为8×10 ^-12 g / L，SERS增强因子高达1.87×10 ⁸。