title: Fabrication of fluorescent SiO2@zeolitic imidazolate framework-8 nanosensor for Cu(2+) detection.
abstract: A simple strategy to fabricate a fluorescent SiO2@zeolitic imidazolate framework-8 (ZIF-8) core-shell nanosensor for Cu(2+) detection was demonstrated in this work. The nanosensor was synthesized using carboxyl-functionalized SiO2 nanoparticles (SiO2 NPs) as a template to induce the growth of ZIF-8 on its surface. The porous SiO2@ZIF-8 exhibited extremely good adsorption properties and a large specific surface area to accumulate Cu(2+), and the pyridyl nitrogen sites in imidazole played vital roles in the recognition of Cu(2+). The fluorescent intensity decreased linearly with the increasing of Cu(2+) concentration in the range of 10-500 nM and the detection limit was estimated to be 3.8 nM. The SiO2@ZIF-8 nanosensor could be further used to determine trace amounts of Cu(2+) in real water samples, while some previous sensors had to be dispersed in organic solution for use, such as DMSO and MeCN. The core-shell nanostructures of SiO2@ZIF-8 made it possible for it to be dispersed directly in aqueous solution and prevented ZIF-8 from aggregation, which enhanced the sensing performance of the SiO2@ZIF-8 nanosensor.
authors.affiliation: Key Laboratory of Functional Small Organic Molecule, Ministry of Education, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, People's Republic of China. lwanggroup@aliyun.com.
authors.forename: Yonghai
authors.initials: Y
authors.lastname: Song
authors.forename: Dongqin
authors.initials: D
authors.lastname: Hu
authors.forename: Fenfen
authors.initials: F
authors.lastname: Liu
authors.forename: Shouhui
authors.initials: S
authors.lastname: Chen
authors.forename: Li
authors.initials: L
authors.lastname: Wang