Imine derivative as an analytical probe for Al+3, F− and CN− sensing with antibacterial activity against E. coli – An application of electrochemical and spectrofluorimetric techniques

•Imine derivative as an optical and voltammetric Probe1 for Al+3 and CN− with LoD as10−7 M.•Probe1 is selective for Al(III) in presence of Fe(III) and Cr(III) in ACN:H2O::90:10.•Probe1 sensor for Al(III) in ground water samples and water as an impurity in ACN solvent.•Probe1 and its Al+3 complex exhibit excellent antibacterial activities against E. coli. Diimine benzene and naphthaldehyde based molecular architecture (Probe 1) has been synthesized and its sensing behavior found selective for Al+3 ions with the lowest detection limit of 6.7x10−7 M. The probe signaled the binding event through the formation of an absorption band at 406 nm with a new emission band at 504 nm. Chelation induced enhanced fluorescence (CHEF) effect and restricting PET phenomena are proposed as the mechanism. Photophysical data is supported with electrochemical studies of the probe for Al+3 ions. Probe 1 showed selective determination of CN− and F− ions with a new absorption band at 412 nm and “turn-on” fluorescence band at 460 nm with the lowest detection limit of 1x10−7 M. The proposed mechanism of the anion detection was confirmed by 1H NMR titrations. DFT calculations were used to confirm the experimental results. Presence of water as an impurity to the extent of 0.4% in acetonitrile was detected using Probe-Al+3 complex as a sensor. Furthermore, antibacterial activity of the Probe 1 and its aluminium complex was explored against non-pathogenic E. coli. Fluorescence imaging and SEM analysis were in strong agreement with the effective antibacterial activity of Probe 1 and its aluminium complex.