A luminescent metal organic framework with high sensitivity for detecting and removing copper ions from simulated biological fluids

Abstract

The crystal structure of Cd-MOF-74 was obtained for the first time that possesses high sensitivity for the detection of copper ions from water and simulated biological fluids based on changes in luminescent intensity. Furthermore, Cd-MOF-74 could selectively remove Cu²⁺ from simulated biological fluids that contain Mg²⁺, Co²⁺, Zn²⁺, Fe²⁺, Ni²⁺, Na⁺, and K⁺. The adsorption capacity of this adsorbent for copper ions reached 189.5 mg g⁻¹ and it quickly adsorbed copper ions within 10 minutes under 10 ppm Cu²⁺ in the simulated biological system. XPS, PXRD, and gas adsorption measurements revealed that this high sensitivity and selectivity of Cd-MOF-74 resulted from the partial substitution of Cd²⁺ by Cu²⁺ in the framework. Although many MOF materials have been employed for sensor or selective adsorption of Cu²⁺, Cd-MOF-74 is the first example of MOFs showing both capabilities in simulated biological fluids, which represents a pioneering work that extends the applications of MOF materials in the biological field.