A Turn-On Chromogenic and Fluorogenic 2-Aminobenzophenyl-Isoniazid Sensor for Selective Detection of Cu²⁺ Ions in Water Samples and Vegetables

A novel 2-aminobenzophenyl-isonazid (BPNH) was developed for Turn-On green emissive sensor for Cu2+ ions. The probe is highly selective to Cu2+ ions in presence of interfering heavy metals. The presence of acid hydrazide and amine group facilitate the strong interaction of the probe with Cu2+ ion. The optical spectral investigation of the probe (E)-N '-((2-aminophenyl)(phenyl)methylene)isonicotinohydrazide (BPNH) with Cu2+ ions showed Intramolecular Charge Transfer (ICT) process and Ligand-Metal Charge transfer (LMCT) are responsible for fluorescence Turn-On emission. The ensemble BPNH+Cu2+ is reversible with addition of S2- ions. The sensor BPNH displayed a lowest detection limit, DL=8.32x10(-7) M (nanomolar). The real sample analysis application of the ligand BPNH for Cu2+ quantification has been demonstrated with water samples collected from various sources and vegetable extracts.