An easy-to-use phosphate triggered zinc-azophenine complex assisted metal extrusion assay: A diagnostic approach for chronic kidney disease and in silico docking studies

Abstract

Regular monitoring of H2PO4- is inevitable owing to its physiological, chemical as well as environmental significance. Herein, a new and promising azophenine-functionalized Zn2+ complex, CN-1·Zn2+ is rationally designed for the selective and sensitive colorimetric detection (LOD = 67.9 ppb) of monophosphorylated species, H2PO4- based on H2PO4--specific metal-extrusion assay through hypsochromic shift in the UV–vis spectra. The sensing phenomenon has been authenticated via UV–vis, ESI-MS, CV, LSV, 1H NMR studies with theoretical (DFT) substantiation. CN-1·Zn2+ has been exploited towards two-input-two-output logic circuitry fabrication, advantageous for molecular-level information storage. Moreover, TLC strip-based contact mode analysis is beneficial for its on-spot applicability. Smartphone-assisted chromogenic recognition efficiency of CN-1·Zn2+via RGB analysis has been well-correlated with spectrophotometric outcomes, demonstrating reliability of the present method. Phosphate detection efficacy of CN-1·Zn2+ in serum specimens with qualified recovery (90.9–98.9 %) makes it a potential diagnostic tool for monitoring chronic kidney disease (CKD). Additionally, CN-1·Zn2+ exhibited DNA binding activity through non-intercalation mode, examined via UV–vis, fluorescence spectroscopic studies with in silico docking. This is the first Zn2+-complex in azophenine family, effectively employed for smartphone-assisted phosphate detection having promising DNA-binding activity, thereby leaving a sustainable footprint in the domain of supramolecular and bio-medical functional world of applications.