新型荧光二氧化硅微球同步吸附检测水溶液中的重金属离子

Simultaneous determination of aqueous heavy ions adsorbed by novel fluorescent SiO2 microspheres

利用量子点配体与巯基硅烷之间的配体交换,将量子点掺杂在二氧化硅微球内,保证微球的荧光特性,同时微球表面覆盖的大量巯基用于对重金属离子(Cu2+,Pb2+)的吸附.实验结果表明,直径在1μm左右的荧光微球,最大吸附量能够大于100mg·g-1,平衡吸附时间为1min,且随着重金属离子吸附量的增加,荧光强度降低,可通过监测微球的荧光强度,得到微球对重金属离子的吸附量.因此,该荧光微球是一种良好的重金属离子传感吸附剂.

Based on the exchange of ligands between 3-mercaptopropyltrimethoxysilane and 3-mercaptopropionic acid capped quantum dots(QDs),QDs were doped into SiO2 microspheres successfully.The SiO2 microspheres have excellent fluorescent properties and thiol was used to absorb heave metal ions on the surface of microspheres,such as,copper and lead ions.The experimental results show that the adsorption process of copper and lead ions finished within 1 min and the maximum of copper ions adsorption was 101 mg·g-1,lead ions was 83 mg·g-1.Meanwhile,fluorescent intensity of microsphere will decrease with the increase of adsorption of heave metal ions.Therefore,the fluorescent SiO2 microspheres could act as an ideal sensor for the process of adsorption of heavy metal ions.