Luminescent CS-SiO2@TEuTTA membrane for simultaneous detection and adsorption of copper(II) ions

Abstract

Detection and adsorption of excessive copper ions are essential for protecting human health and the ecosystem structure due to the toxicity of copper. Herein, relying on the unique structural properties of chitosan (CS), a CS-SiO2@TEuTTA membrane was designed and prepared for simultaneously detection and adsorption of copper ions. Lanthanide complexes were coated on the surface of SiO2 to prepare photoluminescent SiO2@TEuTTA nanospheres. Next, dual-functional CS-SiO2@TEuTTA membrane was prepared by depositing a mixing solution of CS and SiO2@TEuTTA onto a PVDF substrate. The result shows that the CS-SiO2@TEuTTA membrane has an adsorption capacity of 51.28 mg/g. Furthermore, the fluorescence of the CS-SiO2@TEuTTA membrane can be quenched by copper ions. The membrane exhibits good selectivity and sensitivity for copper ions in the range of 2–100 μM and the detection limit of the membrane is 0.18 μM. In particular, the CS-SiO2@TEuTTA membrane provides greater sensitivity to copper ions than SiO2@TEuTTA nanospheres, owing to the enrichment of copper ions in CS.