Development of Cross‐Linked Chitosan‐Triazole Schiff Bases: Synthesis, Characterization, and Antibacterial Activity Evaluation

Abstract The increasing use of bioactive compounds with antimicrobial potential has emerged as a promising alternative to synthetic drugs and disinfection, addressing the challenge of multidrug‐resistant (MDR) microbial strains in community and hospital settings. This study reports the one‐pot synthesis, the characterization, and the antibacterial evaluation of novel chitosan‐triazole Schiff bases (cross‐linked) ( CsT and CsBT ). The structures of these derivatives were confirmed using Fourier transform infrared (FT‐IR) spectroscopy, X‐ray diffraction (XRD), ultraviolet‐visible (UV–vis) spectroscopy, and thermal analysis (TG/DTA and DSC). The antibacterial activity was evaluated against a range of bacterial strains, including Gram‐positive ( Enterococcus faecalis), (Staphylococcus aureus), (Bacillus subtilis ), and Gram‐negative ( Escherichia coli), (Klebsiella pneumoniae), (Pseudomonas aeruginosa ) bacteria. The results demonstrated significant antibacterial activity, with inhibition zones ranging from 10 to 20 mm. Notably, CsT exhibited the highest activity against E. coli (20 mm) and K. pneumoniae (19 mm), surpassing the performance of unmodified chitosan. The minimum inhibitory concentration values (MIC) for CsT were as low as 16 µg/mL for K. pneumoniae bacteria and 32 µg/mL for E. coli bacteria, indicating potent antibacterial efficacy. The enhanced antibacterial activity, coupled with the improved thermal stability and structural properties of CsT and CsBT , underscores their potential for further development and application in combating MDR bacterial infections.