Eco-friendly approach for the removal and simultaneous detection of cyanide toxins from drinking and wastewater...

The consumption of drinking water and wastewater with low concentrations of toxic cyanide ions (CN^-) can result in bioaccumulation, posing a significant risk to human health and leading to sudden death. Thus, sensitive detection and selective removal approaches for ultra-trace concentrations of highly toxic CN^- from water sources are of particular interest to a widening cohort of water purification researchers. In this study, we fabricated 3D hierarchy and face-centered cubic (fcc) surfaces of zirconium organic frameworks (ZOFs) that are decorated tightly with organic colorant dressers, enabling the fabrication of multi-functional captor/sensor microstructures (CSMs). The CSM structures can customize a wide range of functions of naked-eye detection, removal, and recovery of extremely toxic CN^- in drinking and wastewater environments in a simultaneous, one-pot process. The visual CSM function was controlled via the modification of cubic fcc surfaces of ZOFs with hydrophobic colorant receptors, leading to the formulation of multi-functional capture centers, resembling branches, onto the entire surface scaffolds. Such CSM models provide sensitive and selective capture/trapping/removal and detection of CN^- in diverse water sources and environments. The CSM models demonstrated significant capabilities in the selective and sensitive detection of CN^- (48 ppt, parts per trillion) in water samples within seconds (40 s). Moreover, the CSM models demonstrate a high CN-adsorption capacity of 137.17 mg/g under optimal adsorption conditions. In terms of controlling CN-environmental waste, the chemical/physical features of CSM models (i.e., large surface area-to-volume ratios, heterogeneous active sites, uniform 3D geometries, and multifaced cubic surfaces) efficiently facilitate a stable CN-recovery process without structural degradation, despite rigorous chemical treatment across numerous cycles. The effective reusability of the CSM design in a wide range of drinking and wastewater sources fosters an eco-friendly approach for CN^- waste management, minimizing its harmful release into the environment.