CHARACTERIZATION OF POLYHYDROXYBUTYRATE FUNCTIONALIZED WITH AgNPS FOR APPLICATION IN IMMOBILIZATION OF LIPASES VIA GREEN SYNTHESIS

This study aimed to characterize silver nanoparticles (AgNPs) obtained by green synthesis and to evaluate polyhydroxybutyrate (PHB) functionalized with AgNPs for potential application in microbial lipase immobilization. The methodology involved extracting bioactive compounds from coffee, which served as natural reducing agents in the green synthesis of AgNPs. Subsequently, PHB was functionalized with these nanoparticles through a heat treatment in a Dubnoff bath, ensuring its incorporation into the polymer. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The XRD results confirmed the presence of AgNPs in PHB, as evidenced by a characteristic peak at 38.1° (111 plane of the silver face-centered cubic- FCC structure). FTIR analysis showed bands attributed to PHB functional groups and the crosslinking agent glutaraldehyde, which enhances hydrophilicity and facilitates interaction with biomolecules. SEM images revealed morphology changes, with the functionalized PHB exhibiting a less porous and more homogeneous surface, suggesting a structural modification due to AgNPs incorporation. The results indicated that the green synthesis of AgNPs was effective and that their incorporation into PHB promoted significant structural changes, making it a promising material for lipase immobilization and biotechnological applications.