Vapor I2-Mediated Robust Aggregation/Etching of Silver Nanoparticles for Sensitive and On-Site SERS Monitoring of Iodine in Seawater

作者：Zhi‐Nan Chen, Ruiqi Gao, Xueshan Chen, Zhankuo Zhang, Yao Lin, Kailai Xu, Jinyi Zhang, Chengbin Zheng · 发表于：ACS Sensors · 年份：2025 · DOI：10.1021/acssensors.5c01101 · 被引用次数：3 · 研究领域：Gold and Silver Nanoparticles Synthesis and Applications、Advanced biosensing and bioanalysis techniques、Biosensors and Analytical Detection

While oceanic iodine plays a critical role in monitoring marine pollution and biogeochemical cycles, existing detection methods suffer from compromised sensitivity, laborious pretreatment, and field-incompatible operation. Herein, we present a vapor-phase molecular recognition strategy that leverages iodine (I 2 )-induced structural transformation of silver nanoparticles (AgNPs) for surface-enhanced Raman scattering (SERS) indirect detection, with rhodamine 6G (Rh6G) as a Raman probe of seawater iodine. Spectroscopic and electron microscopic results showed that I 2 induced stronger sequential aggregation and anisotropic etching of nanoparticles than I –, effectively suppressing SERS enhancement. Theoretical calculations reveal that I 2 exhibits a 3-fold stronger binding affinity with AgNPs compared to I – . By integrating headspace sampling with paper-based SERS substrates, this method achieves matrix interference elimination through gas–solid phase separation while enhancing sensitivity via vapor preconcentration. The developed approach demonstrates a low detection limit of 15.1 nM for iodide (RSD = 5.0%, n = 15), with a linear response across 50–1000 nM, and no significant interference with coexisting anions at 1000-fold higher concentrations. Field deployment along the Southeast China Sea coastline showed excellent correlation with standard mass spectrometry measurements. This work not only elucidates the molecular-level interaction between I 2 and noble metal nanostructur...