State Key Laboratory of Digital Medical Engineering, School of Biological Science and Medical Engineering, Southeast University, Nanjing 211189, China; Institute of Biomaterials and Medical Devices, Southeast University, Suzhou 215163, China; Southeast University Shenzhen Research Institute, Shenzhen 518000, China.
Pharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China; Innovation Institute for Artificial Intelligence in Medicine of Zhejiang University, Hangzhou 310018, China.
J Hazard Mater. 2024 Apr 5;467:133763. doi: 10.1016/j.jhazmat.2024.133763. Epub 2024 Feb 11.
Practical gas sensing application requires sensors to quantify target analytes with high sensitivity and reproducibility. However, conventional surface enhanced Raman scattering (SERS) sensor lacks reproducibility and quantification arising from variations of "hot spot" distribution and measurement conditions. Here, a ratio-dependent SERS sensor was developed for quantitative label-free gas sensing. Au@Ag-Au nanoparticles (NPs) were filtered onto anodic aluminum oxide (AAO) forming Au@Ag-Au@AAO SERS substrate. 4-MBA was encapsulated in the gap of Au@Ag-Au and served as the internal standard (IS) to calibrate SERS signal fluctuation for improved quantification ability. Combined with headspace sampling method, SO residue in traditional Chinese medicine (TCM) can be extracted and captured on the immediate vicinity of Au@Ag-Au surface. The intensity ratio I/I showed excellent linearity within the range of 0.5 mg/kg-500 mg/kg, demonstrating superior quantification performance for SO detection. Signals for concentration as low as 0.05 mg/kg of SO could be effectively collected, much lower than the strictest limit 10 mg/kg in Chinese Pharmacopoeia. Combined with a handheld Raman spectrometer, handy and quantitative TCM quality evaluation in aspect of SO residue was realized. This ratiometric SERS sensor functioned well in rapid on-site SO quantification, exhibiting excellent sensitivity and simple operability.
实用的气体传感应用需要传感器具有高灵敏度和重现性来定量分析目标分析物。然而，传统的表面增强拉曼散射（SERS）传感器由于“热点”分布和测量条件的变化而缺乏重现性和定量能力。在这里，开发了一种基于比率依赖的 SERS 传感器用于定量无标记气体传感。Au@Ag-Au 纳米颗粒（NPs）被过滤到阳极氧化铝（AAO）上，形成 Au@Ag-Au@AAO SERS 基底。4-巯基苯甲酸（4-MBA）被封装在 Au@Ag-Au 的间隙中，用作内标（IS），以校准 SERS 信号波动，从而提高定量能力。结合顶空采样方法，可以从中药材（TCM）中提取并捕获残留的 SO，并将其捕获在 Au@Ag-Au 表面的附近。I/I 强度比在 0.5-500mg/kg 范围内呈现出极好的线性关系，表现出对 SO 检测的优越定量性能。可以有效地收集到浓度低至 0.05mg/kg 的 SO 信号，远低于中国药典规定的 10mg/kg 的最严格限制。结合手持式拉曼光谱仪，实现了便捷、定量的 TCM 质量评估，从 SO 残留方面进行评价。这种比率型 SERS 传感器在快速现场 SO 定量方面表现良好，具有出色的灵敏度和简单的可操作性。
