Engineering Research Center of Bio-process, MOE, School of Food and Biological Engineering, Intelligent Manufacturing Institute, Hefei University of Technology, Hefei 230009, PR China.
Engineering Research Center of Bio-process, MOE, School of Food and Biological Engineering, Intelligent Manufacturing Institute, Hefei University of Technology, Hefei 230009, PR China; Changsha University of Science & Technology, Changsha, 410114, Hunan, China.
Food Chem. 2025 Jan 15;463(Pt 3):141375. doi: 10.1016/j.foodchem.2024.141375. Epub 2024 Sep 19.
Mercury ions (Hg) are highly toxic heavy metals that are commonly found in natural environments. Owning to their non-biodegradability and accumulation in the food chain, the precise detection of trace amounts of Hg is essential for preventing chronic accumulation and ensuring food safety. In this study, we present a dual-mode paper sensor for simultaneous colorimetric and Surface-Enhanced Raman Spectroscopy (SERS) detection of Hg in tea, achieving ultrasensitive, rapid, and on-site screening. 4-Mercaptopyridine (4-MPY) was effectively chemisorbed onto the gold nanoparticles (AuNPs), acting as a signal probe for colorimetric methods. Moreover, it can produce plasmonic hot spots for SERS by interacting with the pyridine ring. To enhance the signal intensity of both colorimetry and SERS, a silver shell is in-situ grown on the surface of AuNPs captured on the paper sensor by reduction of Ag, achieving signal amplification. The visual limit of detection (LOD) for the colorimetric biosensor is 2.5 pM, while the LOD of SERS is 0.48 pM with this dual-mode paper sensor. The sensitivity of both the colorimetric method and SERS was improved by approximately 200 and 500 times, respectively, with the designed signal amplification strategy. The system allows for multiple parallel screening of the same sample, ensuring accurate results without any false-positive or false-negative. This study provides a valuable platform for the accurate detection of various other heavy metal ions and provides effective strategies for improving the performance of colorimetric methods.
汞离子 (Hg) 是高度有毒的重金属，普遍存在于自然环境中。由于其不可生物降解性和在食物链中的积累，精确检测痕量 Hg 对于防止慢性积累和确保食品安全至关重要。在这项研究中，我们提出了一种用于同时比色和表面增强拉曼光谱 (SERS) 检测茶中 Hg 的双模纸传感器，实现了超灵敏、快速和现场筛选。4-巯基吡啶 (4-MPY) 被有效地化学吸附在金纳米粒子 (AuNPs) 上，作为比色法的信号探针。此外，它可以通过与吡啶环相互作用产生等离子体热点，用于 SERS。为了增强比色法和 SERS 的信号强度，通过还原 Ag，在纸上传感器上捕获的 AuNPs 表面原位生长银壳，实现信号放大。比色生物传感器的目视检测限 (LOD) 为 2.5 pM，而双模纸传感器的 SERS LOD 为 0.48 pM。通过设计的信号放大策略，比色法和 SERS 的灵敏度分别提高了约 200 倍和 500 倍。该系统允许对同一样品进行多次平行筛选，确保结果准确，没有任何假阳性或假阴性。这项研究为准确检测各种其他重金属离子提供了有价值的平台，并为提高比色法的性能提供了有效的策略。
