A Urea-Functionalized Chemoreceptor for Expeditious Chromogenic Recognition of Toxic Industrial Pollutants Cu2+ and CN- from Real Water Sources and Biofluids: Diagnosis of Wilson's disease from Human Urine

A urea-functionalized chemoreceptor 1,5-bis(2,4-dinitrophenyl)carbonohydrazide (BDC) with versatile applications has been reported in this work. BDC displayed ditopic sensitivity toward toxic industrial pollutants Cu2+ and CN- from a purely aqueous medium. BDC has been structurally authenticated by ESI-MS, H-1-NMR, and SCXRD. It can undergo promising naked eye detection in the existence of the targeted analytes (pale yellow to dark purple for Cu2+ and pale yellow to dark brown for CN-) in the sub-nanomolar detection threshold (Cu2+: 46 x 10(-8) M and CN : 92 x 10(-8) M). The LMCT-ICT and intermolecular H-bonding pathways rationalize the underlying sensing mechanism. A good substantiation of solution-state experimental outcome and theoretical (DFT) evidence further authenticated the recognition pathway. BDC displays reversibility with alternate CN- and Cd2+ addition up to several cycles that serves to be a reliable system toward mimicking molecular logic gate functions. The cytotoxicity assay of BDC on Bacillus thuringiensis (Bt) exhibit its biocompatibility. Furthermore, BDC can efficiently undergo rapid on-site Cu2+ and CN- detection in varying real water sources, and interestingly, BDC can recognize the presence of Cu2+ from biofluids like fetal bovine serum (LOD 13 mu M) with a distinct colorimetric response. Moreover, the unprecedented novelty of biocompatible BDC lies in its ability to detect Cu2+ from a human urine specimen as low as 1.5 mu M by concentration-dependent discriminative chromogenic responses. This makes BDC an inimitable exploratory symptomatic tool for Wilson's disease, which to the best of our knowledge to date has been rarely explored in the supramolecular realm. One step ahead, solid-state on-spot chromogenic detection of aqueous Cu2+ and CN- by the dip stick method escalates the practical application of this work.