Electronic Theses and Dissertation

BIOSINTESIS NANOPARTIKEL PERAK MENGGUNAKAN Aspergillus flavus SERTA PENGUJIAN AKTIVITAS ANTIMIKROBA TERHADAP PATOGEN UDARA

Biosynthesis of silver nanoparticles (AgNPs) using biological methods has become an environmentally friendly alternative method. This study aims to study the biosynthesis mechanism of silver nanoparticles using Aspergillus flavus as a reducing and stabilizing agent, analyze the size, shape, and physicochemical characteristics of the resulting silver nanoparticles, and evaluate the potential application of silver nanoparticles as antimicrobial agents against airborne pathogens. The biosynthesis process was carried out by mixing silver nitrate (AgNO3) solution with fungal culture filtrate, and observed color changes as an initial indication of nanoparticle formation. Characterization was carried out using UV-Vis spectroscopy, FTIR, SEM, PSA, and zeta potential. The UV-Vis results showed a typical absorption peak at a wavelength of around 413 nm indicating the presence of AgNPs. The FTIR spectrum showed the presence of functional groups -OH, -NH, C=O, C-N, C-O, C-O-C, and aromatic C-H from fungal metabolites act as reducing and stabilizing agents in AgNPs biosynthesis. Analysis using SEM showed that the particle morphology was spherical, relatively smooth, unevenly distributed, and other parts experience agglomeration. The particle size of AgNPs detected by PSA was 78.84 nm which indicates that the size obtained was below 100 nm, while the zeta potential value is -21.9 mV which indicates good colloidal stability. Antimicrobial activity tests carried out using various concentrations showed that AgNPs from samples composition 7 and 16 were effective in inhibiting the growth of airborne pathogens. These results prove that Aspergillus flavus has the potential as a biogenic agent in the synthesis of stable and active AgNPs against airborne pathogens. Keywords: Silver nanoparticles (AgNPs), biosynthesis, Aspergillus flavus, airborne pathogens, antimicrobial activity