ESIPT-based dual-emissive perimidine derivative as a rapid and sensitive sensor for Cu2+ and Al3+: Construction of memory device, 2-to-1 encoder and 1-to-2 decoder

Abstract

An ESIPT based fluorescent perimidine derivative oPSDAN was developed and characterized by 1H NMR, 13C NMR and mass spectroscopy. The study of the photo-physical properties of the sensor unveiled its selectivity and sensitivity towards Cu2+ and Al3+ ions. The sensing of ions was accompanied by colorimetric change (for Cu2+) as well as emission turn-off response. The binding stoichiometries of sensor oPSDAN with Cu2+ ion and Al3+ ions were determined to be 2:1 and 1:1, respectively. The binding constants and detection limits for Cu2+ and Al3+ were calculated from the UV–vis and fluorescence titration profiles as, 7.1 × 104 M−1, 1.9 × 104 M−1 and 9.89 nM, 1.5 × 10−8 M, respectively. The mechanism was established by 1H NMR as well as mass titrations and was supported by DFT and TD-DFT calculations. The UV–vis and fluorescence spectral results were further utilized for construction of memory device, encoder and decoder. Sensor-oPSDAN was also tested for determining Cu2+ ions in drinking water.