Advanced Pyrano[2,3-c]Pyrazole-Based Azo Dyes: Enhanced Dyeing Performance and Antibacterial Activity of wool, polyester and nylon fabics via Gold Nanoparticle Functionalization

Pyrano[2,3-c]pyrazole-based azo dyes have attracted considerable interest due to their vibrant coloration, chemical stability, and versatile applications. This study reports the synthesis, characterization, and performance evaluation of novel pyrano[2,3-c]pyrazole-based azo dyes (M1-M3). Compound M2 was further functionalized with gold nanoparticles (AuNPs) to enhance its dyeing efficiency and antibacterial properties. The structures of all synthesized dyes were confirmed via elemental analysis, FT-IR, NMR, and mass spectrometry. These dyes were applied to wool, polyester, and nylon fabrics using optimized dyeing techniques, including high-temperature and high-pressure (HTHP) methods. Color strength (K/S values) and fastness properties—including resistance to light, rubbing, washing, and perspiration—were comprehensively evaluated. Notably, the AuNP-functionalized M2 demonstrated superior antibacterial activity against both Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive), establishing it as a promising candidate for multifunctional textile applications. These findings highlight the synergistic benefits of combining nanotechnology with organic dye chemistry, providing valuable insights for developing advanced functional textiles with enhanced aesthetic and bioactive properties.