通过溶剂热、溶胶-凝胶和共嫁接技术开发制备了一种基于芘功能化的核壳型磁性二氧化硅纳米微球的可回收汞离子光学传感器。相对于其他竞争金属离子, 获得的多功能纳米微球对Hg2+具有良好的荧光传感性能和选择性。多功能微球的荧光强度与Hg2+浓度之间显示出良好的Stern-Volmer线性关系(R2＝0.998 3), 其检测限为2.3×10-8 mol·L-1。该材料对汞离子的荧光响应具有可逆性, 利用EDTA溶液处理可实现多次重复使用。此外, 芘功能化的磁性二氧化硅纳米微球可以有效地除去水溶液中的Hg2+, 并且通过施加外部磁场可实现简单快速的分离。上述结果表明, 这种功能化核壳型磁性二氧化硅微球在同时检测和去除环境污染物方面具有良好的发展前景与应用潜力。

A recyclable mercury(Ⅱ) optical sensor based on pyrene-functionalized core-shell magnetic silica nanosphereswas developed and demonstrated by sol-gel grafting reaction. The obtained multifunctional microspheres displayed excellent fluorescence sensitivity and selectivity towards Hg2+ over other competing metal ions. A good linearity Stern-Volmer working plot (R2=0.998 3) between the fluorescence intensity of multifunctional microspheres and the concentration of Hg2+ was constructed with a satisfactory detection limit of 2.3 × 10-8 mol·L-1. Their fluorescence response in the presence of Hg2+ is found to be almost reversible when treated by EDTA solution. Moreover, these pyrene-functionalized magnetic silica nanospheres can efficiently remove Hg2+ in aqueous solution and easily separated by appling an external magnetic field. These results indicate that functionalized core-shell magnetic silica microspheres are potentially promising materials for simultaneously detecting and removing environmental pollutants.