基于表面增强拉曼光谱免疫层析法的卷烟纸中重金属元素快速检测

Lateral Flow Immunoassay Method Based on Surface Enhanced Raman Spectroscopy for Rapid Detection of Heavy Metal Elements in Cigarette Paper

关键词:  卷烟纸  重金属  快速检测  表面增强拉曼光谱  免疫层析

Key Words:cigarette paper  heavy metal  rapid detection  SERS  lateral flow immunoassay

摘要:为实现卷烟纸中重金属的高敏、定量及快速检测，本研究提出了一种基于表面增强拉曼散射（SERS）信号的新型免疫层析技术。SERS免疫层析法使用一种树莓状的SERS标签Fe₃O₄@树莓状金磁性纳米颗粒（Fe@RAu）捕获样本中的金属残留物，Fe@RAu表面的Au壳能够产生拉曼热点效应以增强其表面修饰的5,5'-二硫代双(2-硝基苯甲酸)（DTNB）分子的拉曼信号，且其Fe₃O₄内核可被外加磁力吸附以富集样本中的靶标。基于这些特性，SERS免疫层析法具有超高的检测灵敏度和定量能力。结果表明，该方法同时检测卷烟纸燃烧灰烬中镉（Cd²⁺）、铬（Cr³⁺）、铅（Pb²⁺），3种重金属离子的灵敏度分别达1.424、0.937和1.568 ng/kg，检测实际卷烟纸标准样品的加标回收率>90%，相对标准偏差（RSD）<10%，检测时间（包含预处理）<30 min。

Abstract:To achieve highly sensitive， quantifiable， and rapid detection of heavy metals in cigarette paper， a novel lateral flow immunoassay technique based on surface enhanced raman spectroscopy （SERS） signals was studied and proposed. SERS lateral flow immunoassay method utilized a raspberry-like SERS label Fe₃O₄@Raspberry-like Au magnetic nanoparticles （Fe@RAu） to capture metal residues in samples. Au shell on the Fe@RAu surface could generate Raman hot spot effects to enhance the Raman signals of DTNB molecules modified on its surface， while its Fe₃O₄ core could be attracted by external magnetic forces to concentrate targets in the sample. Based on these characteristics， SERS lateral flow immunoassay method demonstrated ultra-high detection sensitivity and quantification capability. The results showed that the SERS lateral flow immunoassay method achieved sensitivity levels of 1.424， 0.937， and 1.568 ng/kg for the simultaneous detection of three heavy metals， including cadmium （Cd²⁺）， chromium （Cr³⁺）， and lead （Pb²⁺） in cigarette paper ash. The spiked recovery rate for actual cigarette paper standard samples was>90%， the relative standard deviation （RSD）was<10%， and the entire detection process （including pretreatment） was<30 min.