Thimaradka, V.Pangannaya, S.Mohan, M.Trivedi, D.R.2026-02-052018Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy, 2018, 193, , pp. 330-33713861425https://doi.org/10.1016/j.saa.2017.12.041https://idr.nitk.ac.in/handle/123456789/25209A series of new receptors PDZ1–3 based on 2-(arylidenehydrazinyl)pyridines have been designed and synthesized for the detection of biologically and environmentally important ions. The colorimetric detection of CO<inf>3</inf>2 ? using neutral organic receptor PDZ-1 has been achieved with characteristic visual colour change from yellow to green accompanied by a large redshift of 215 nm in absorption maxima. UV–Vis spectroscopic and cyclic voltammetric studies reveal the stoichiometry of binding and electrochemistry of host-guest complex formation. The binding constant was found to be 0.77 × 104 M? 2. In addition, electrochemical studies provide an insight into the stability of the complex. DFT studies performed on the PDZ-1 and PDZ-1 ? CO<inf>3</inf>2 ? complex reveal the binding mechanism involved in the anion detection process. PDZ-1 is highly selective for carbonate and does not show any colorimetric response towards any other anions or cations, while PDZ-2 and PDZ-3 remain inactive in the ion detection process. The limit of detection (LOD) and limit of quantification (LOQ) of PDZ-1 for carbonate was found to be 0.11 mM and 0.36 mM respectively. Considerable binding constant and limit of detection make PDZ-1 to be used as a real time sensor for the detection of carbonate in environmental and biological samples. © 2017 Elsevier B.V.BinsCarbonationColorColorimetryElectrochemistryNegative ionsPyridineCarbonate ionsColorimetricColorimetric detectionCyclic voltammetricElectrochemical studiesEnvironmental and biological samplesHost guest complexesLimit of quantificationsIons