Multifunctional Biogenic Silver/Hydroxyapatite Nanocomposite: Photocatalytic Crystal Violet Removal, Antihemolytic Performance, and Broad-Spectrum Antimicrobial Activity

This study reports the sustainable synthesis and thermal, morphological, and structural characterization of multifunctional silver/hydroxyapatite nanocomposite prepared from recycled caprine bone. The organic extract from caprine bone was characterized using Fourier Transform Infrared (FTIR) and Ultraviolet–Visible Spectroscopy (UV-Vis). The biogenic hydroxyapatite (CHAP) and its silver composite (Ag@CHAP) were characterized using thermal gravimetric analysis (TGA), Raman spectra, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and transmission electron microscope (TEM). The photocatalytic activity of Ag@CHAP was quantitatively confirmed through the degradation of Crystal Violet (5 ppm) under sunlight, achieving a high removal efficiency of 99.8% under optimum conditions, demonstrating significant potential for wastewater remediation. Ag@CHAP also demonstrated enhanced antimicrobial activity compared with CHAP and showed broad-spectrum efficacy against clinical human isolates P. aeruginosa ATCC 10145, E. coli ATCC 35218, S. aureus ATCC 25923, and C. albicans (human isolate). The in vitro hemolytic-activity assays revealed that both CHAP and Ag@CHAP had no hemolytic activity after 24 h of red blood cells incubation and effectively reduced lead-induced hemolysis from 86.73% to 39.35% and 49.13%, respectively. These findings confirm CHAP and Ag@CHAP as stable, biocompatible, and high-performance materials with promising applications in the sustainable water-treatment and biomedical fields.