An Isoniazid Based Schiff Base Sensor for Selective Detection of Pd²⁺ Ions

Here, we developed a novel isoniazid based fluorescent probe (E)-N'-(thiophen-2-ylmethylene)isonicotinohydrazide (TINH) through simple condensation reaction and employed for selective detection of Pd²⁺ ions with a low detection limit of 4.102 × 10^-11 M. Among the many existing cations, TINH bound Pd²⁺ ions with an association affinity of 9.794 × 10⁵ M^-1. Adding Pd²⁺ ions to ligand solution increased the absorption intensity in UV-Visible and quenched the emission intensity in fluorescence spectroscopic experiments. More importantly, this TINH complexed to Pd²⁺ ions in 1:1 stoichiometric ratio. To evaluate the stability of complexed system, pH experiments has been performed. The binding insights among the ligand and Pd²⁺ ions has been confirmed by IR spectroscopic and MASS spectrometric methods. Additionally, TINH also applied to real water samples for the identification and measurement of Pd²⁺ ions. Hence, this system could be highly applicable for detection of Pd²⁺ ions in environmental and industrial samples with in low detection range.