Thiazole derived Schiff base ligand as a naked-eye colorimetric chemosensor for selective and sensitive detection of bismuth (III)

Abstract

A Schiff base N-(5-chlorosalicylidene)-4-(p-fluorophenyl)-2-aminothiazole (N-5CSFPAT) was newly synthesized and examined as a chemosensor. N-5CSFPAT is capable of coordinating and forming a metal complex with Bi3+. The sensing ability of N-5CSFPAT against different metal ions was investigated using a spectrophotometric method. The ligand exhibited a clear color change from colorless to yellow upon binding with Bi3+, which could be easily detected visually. UV–visible spectroscopic analysis revealed a significant hyperchromic shift in the absorption spectrum following the addition of Bi3+, suggesting intramolecular charge transfer (ICT) as the underlying mechanism. The results indicate that N-5CSFPAT possesses a suitable coordination environment for Bi3+ and can be developed as an effective chemosensor for the selective detection of Bi3+ ions in environmental water and real samples. The calculated limit of detection (LOD) and limit of quantification (LOQ) for the analysis of Bi3+ were 0.22 and 1.2 μg mL−1 respectively.