Specific Cu(ii) detection using a novel tricarbazolyl-tristriazolotriazine based on photoinduced charge transfer

Abstract

Tricarbazolyl-tristriazolotriazine, a novel Cu(II)-sensing and selective fluorescent sensor, was designed and synthesised on the basis of the mechanism of photoinduced charge transfer. The synthesised compound exhibits highly sensitive and significant fluorescence decline response towards Cu²⁺ over other metal ions, with a detection limit of 0.2 μM in THF–H₂O (9 : 1, v/v) at neutral pH. Its optical, thermal, electrochemical and morphological properties were studied. The results demonstrate that the compound has high relative fluorescence quantum yield (Φ_F = 0.99) in xylene solution, excellent thermal stability (T_d = 325 °C, T_g = 99.9 °C), wide energy gap (E_g = 4.09 eV), desirable triplet energy (E_T = 2.98 eV) and the highest occupied molecular orbital energy (−5.67 eV). Morphological investigation showed that the compound easily forms ribbon-like microstructures.