Affiliation:
1. School of Physical Sciences, Amrita Vishwa Vidyapeetham, Mysuru Campus, Mysuru 570 026, Karnataka, India
2. Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
Abstract
Herein, we report the synthesis and characterization of a novel Schiff base ligand, (Z)-5-((pyren-1-ylmethylene)amino)-2,4-dihydro-3H-pyrazol-3-one (PMDP). The characterization of ligand PMDP was carried out using ESI-MS, 1H NMR, and UV–Visible spectroscopic techniques. As a probe, PMDP displayed a detectable, colorimetric colour shift in the presence of Cu2+ and Fe2+ ions. The solution was seen to have a light brown colour and to exhibit a fluorometric “turn off” response when Cu2+ and Fe2+ ions were present in a DMSO solution (HEPES 0.01 M, pH = 7.4) at room temperature. Job’s plot revealed that the PMDP binding ratio to Cu2+ and Fe2+ ions was in 1:2 ratio. In contrast to the other metal ions (Cd2+, Mn2+, Co2+, Na+, Ni2+, Cu+, Fe3+, Hg2+, Mg2+, Zn2+, K+, and V5+), the synthesised probe showed exceptional sensitivity and selectivity for detecting Cu2+ and Fe2+ metal ions. The results indicate that the detection limits for Cu2+ and Fe2+ are 0.42 μM and 0.51 μM, respectively. Furthermore, PMDP was efficiently utilised for the quantitative analysis of Cu2+ and Fe2+ in real water samples, RGB colour values in smart phones, logic gate construction, and cell imaging in HeLa cells.