Dipyridine‐Thiophene‐Based Fluorescent Probe: Synthesis, Crystal Structure, and Selective Recognition of Cu2+ Ions

Abstract An efficient fluorescent sensory platform was designed and synthesized for recognition of copper ion (Cu 2+ ) in presence over other competing ions. The probe DTBPA 1 was displayed fluorescence color change upon addition of Cu 2+ ion which was also characterized by spectroscopic techniques especially the fluorescence and colorimetric methods. The probe showed turn‐off fluorescence response to the Cu 2+ ion. The limit of detection for the probe was found to be 0.789 μM while binding stoichiometry for the probe to metal ion was found to be 2 : 1 tested by Jobs analysis. The binding constant for the probe was found to be 1.13×10 6 M −1 . Further the probe was utilized for detection of trace amount of Cu 2+ ion in real water sample with recoveries 98.24 %~104 %. The molecule was further utilized in test strip application. The calculated fluorescence quantum yield was found to be 3.2. The theoretically Density Functional Theory (DFT) calculations were performed for the probe using Gaussian 16 ab initio /DFT quantum chemical simulation and the DFT calculations were supporting the experimental findings.