A colorimetric gold nanoparticle-based sensor, a monolayer of poly(methylacrylic acid)-modified gold nanoparticles (PMAA@Au NPs), was developed for selective detection of Cr3+ ions in aqueous solution. In the presence of Cr3+, PMAA@Au NPs are aggregated by a chelation process, which caused the prominent color changes in response to carboxyl groups in the sensor. Furthermore, the selective detection of Cr3+ in aqueous solution was achieved over 11 other metal ions. The metal complexes were characterized by UV-vis spectroscopy and transmission electron microscopy. In addition, the chelation–dissociation process was reversible via addition of a strong metal ion chelator such as EDTA. The colorimetric sensor used for detecting Cr3+ was able to be recycled at least three times by monitoring optical changes of the PMAA@Au NPs.
一种基于色度法的
金纳米粒子传感器,即聚
甲基丙烯酸修饰
金纳米粒子(PMAA@Au NPs)单层,用于选择性检测
水溶液中的Cr3+离子。在Cr3+存在的情况下,PMAA@Au NPs通过螯合作用聚集,导致传感器中的羧基发生显著的颜色变化。此外,在11种其他
金属离子中,选择性检测
水溶液中的Cr3+。通过紫外-可见光谱和透射电子显微镜对
金属复合物进行表征。此外,通过添加
EDTA等强
金属离子
螯合剂,螯合-解离过程是可逆的。用于检测Cr3+的色度传感器可通过监测PMAA@Au NPs的光学变化至少回收三次。