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 Cu from simulated biological fluids that contain Mg , Co , Zn , Fe , Ni , Na , and K . The adsorption capacity of this adsorbent for copper ions reached 189.5 mg g and it quickly adsorbed copper ions within 10 minutes under 10 ppm Cu 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 Cd by Cu in the framework. Although many MOF materials have been employed for sensor or selective adsorption of Cu , 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.