Synthesis and characterization of a new Schiff-base derivative as an optical nickel (II) chemosensor and its antimicrobial activity

Abstract

A receptor in the form of (E)-(4-(thiophen-2-yl)phenyl)-N-(4H-1,2,4-triazol-4-yl)methanimine Schiff base L was synthesized through the reaction of 4-amino-4H-1,2,4-triazol with 4-(2-thiazol)benzaldehyde. The resulting Schiff base L was characterized by physicochemical techniques such as elemental analysis, UV-vis, Fourier transform infrared (FT-IR), mass spectrometry, and NMR. The Schiff base L receptor was exploited as an optical chemical sensor for nickel (II) metallic cationic concentration determination. The chemosensor demonstrated a consistent absorption intensity change at 385 nm related to the nickel (II) concentration in the range of 0–50 µM with a calibration sensitivity of 0.0052 Abs/µM in addition to calibration linearity (R2 = 0.9839) and possessing a response time of less than 5 mins. Other cations, Fe2 + Cu2+, Co2+, Zn2+, Cd2+, Mn2+, Mg2+, Cr2 + Ag+, Ca2+, Al3+, Li+, Na+, K+, Nd3+, Dy3+, Sm3 + and Tb3+, did not show any considerable change in absorbance intensity, except in the case of Pb2 + and Gd3+, where interference was observed. The mole-ratio method was used to determine the formula for the resulting Ni2 + -ligand complexation, and the Ni2+:ligand mole ratio was 1:1.In vitro antimicrobial activity of the Schiff base L exhibited a bactericidal effect against staphylococcal strains regardless of their different virulence characteristics.