Institute of Food Safety and Environment Monitoring, Fuzhou University, Fuzhou, 350108, PR China.
Xiamen Key Laboratory of Food and Drug Safety, College of Environment and Public Health, Xiamen Huaxia University, Xiamen, 361024, PR China.
Talanta. 2024 Jan 1;266(Pt 2):125081. doi: 10.1016/j.talanta.2023.125081. Epub 2023 Aug 15.
Constructing advanced substrates with excellent features is promising for sensitive surface-enhanced Raman spectroscopy (SERS) detection. Here a novel capillary monolithic 3D structural-substrate SERS platform with Au@cDNA@Ag@Cyanine 3-aptamer nanoparticles (Au@cDNA@Ag@Cy3-Apt NPs) was fabricated for rapid, highly specific profiling of ultra-trace Bisphenol A (BPA). The proposed SERS platform combined both in-capillary SERS and aptamer-affinity recognition strategies, in which the superior SERS properties of Au-Ag NPs, aptamer selectivity, and the advantages of capillary monolith were integrated. A 3D hierarchically porous network was constructed in the monolithic column, which was endowed with rich hotspots for SERS, rapid sample permeation, and better analysis efficiency than most plane-shaped SERS modes. By varying the amount of Ag precursor, the Ag-shell thickness on SERS was finely tuned to guarantee Cy3 label in proximity to the plasmonic surface. Based on the biorecognition of aptamer, the selective identification of BPA occurred and exhibited a significant change in SERS intensity without obvious interference. As a result, the monolithic SERS platform featured facile operation, excellent specificity, and rapid analysis (10 min, much less than the solution-based or planar substrate SERS modes). Ultra-high sensitivity and robust reproducibility for BPA analysis was achieved with a low limit of detection (LOD) at 9.12 × 10 ng/L. The feasibility of this SERS platform for monitoring BPA in water and milk samples was also validated. This work lights a new access to capillary monolithic SERS-sensing platform for ultrasensitive and specific analysis of BPA.
构建具有优异特性的先进基底对于灵敏的表面增强拉曼光谱（SERS）检测具有广阔的前景。在这里，我们构建了一种新型的毛细管整体式 3D 结构基底 SERS 平台，其具有 Au@cDNA@Ag@Cy3-适配体纳米粒子（Au@cDNA@Ag@Cy3-Apt NPs），可用于快速、高特异性地分析痕量双酚 A（BPA）。所提出的 SERS 平台结合了毛细管内 SERS 和适配体亲和力识别策略，综合了 Au-Ag NPs 的优异 SERS 性能、适配体的选择性以及毛细管整体式的优势。在整体式柱中构建了 3D 分级多孔网络，该网络具有丰富的 SERS 热点，可实现快速样品渗透，并且比大多数平面 SERS 模式具有更好的分析效率。通过改变 Ag 前体的量，可以精细调节 SERS 上的 Ag 壳层厚度，以保证 Cy3 标记物靠近等离子体表面。基于适配体的生物识别，BPA 发生了选择性识别，并且 SERS 强度发生了明显变化，而没有明显的干扰。结果，整体式 SERS 平台具有操作简便、特异性好、分析速度快（10 分钟，远快于溶液或平面基底 SERS 模式）等特点。该 SERS 平台对 BPA 的分析具有超高的灵敏度和良好的重现性，其检测限（LOD）低至 9.12×10ng/L。该 SERS 平台在水和牛奶样品中监测 BPA 的可行性也得到了验证。这项工作为毛细管整体式 SERS 传感平台用于 BPA 的超灵敏和特异性分析开辟了新途径。
