Biosynthesis and Characterization of Silver, Copper and Zinc Nanoparticles from Trichoderma koningii

Abstract

Fungal culture filtrates can provide an extracellular route for metal-based nanoparticle formation. This study evaluated the biosynthesis of silver-, copper-, and zinc-based nanoparticles using culture filtrates of Trichoderma koningii and characterised the resulting preparations by UV-Visible spectroscopy, Transmission Electron Microscopy (TEM), and Fourier-Transform Infrared Spectroscopy (FTIR). Culture filtrates obtained after 4, 6, 8, 12, and 15 days were visually compared, and the 15-day filtrate produced the most pronounced colour response for all three metal systems. Silver nanoparticle formation was associated with a dark-brown colour and a maximum UV-Visible absorbance at 435 nm. The copper-based preparation changed from blue to blackish-brown and showed a maximum absorbance at 410 nm, whereas the zinc-based preparation produced a yellowish-white to milky-white precipitate with a maximum absorbance at 330 nm. TEM analysis of the copper-based preparation showed predominantly spherical, polydisperse particles ranging from 11.32 to 42.58 nm. FTIR spectra indicated the participation of hydroxyl-, amino-, and amide-associated functional groups in nanoparticle formation and stabilisation. Bands at 416.62 and 420.48 cm⁻¹ were associated with Cu–O and Zn–O vibrations, respectively. These findings show that T. koningii culture filtrate can function as an extracellular biological system for producing and stabilising silver-, copper-, and zinc-based nanoparticle preparations under the tested conditions