Electrospun PAAm : Bi 2 O 3 Nanofiber Composites With Tailored Structural and Optical Features for Antibacterial Applications: Synthesis, Characterization, and Mechanistic Insights

ABSTRACT The study successfully incorporated bismuth oxide nanoparticles (Bi 2 O 3 ) into electrospun polyacrylamide fibers, yielding a stable nanocomposite. XRD confirmed the monoclinic phase (α‐Bi 2 O 3 ) without secondary phases, with peak intensity increasing with loading. FESEM revealed a near‐homogeneous distribution of particles (60–80 nm) and increased fiber surface roughness. FTIR confirmed shifts in amide bands and BiO bands within 500–600 cm −1 , indicating coordinate interactions and structural stabilization. The energy gap decreased from 4.00 eV for pristine fibers to 3.86 eV at the highest loading, which may favor improved light absorption and charge‐transfer processes. However, these optical results do not provide direct experimental evidence of ROS generation. Biologically, no activity was observed at low concentrations, while 0.09 g/mL produced inhibition zones of approximately 15–18 mm against both Gram‐positive and Gram‐negative bacteria, indicating a loading‐dependent antibacterial response and a critical loading threshold. The response may be influenced by Bi 2 O 3 distribution and accessibility; however, its contribution was not quantitatively separated from increased loading. ROS‐related processes may represent one possible antibacterial mechanism, but their specific contribution was not directly established. These results demonstrate antibacterial potential and support future biosterilization and coating applications, while the specific mechanism requires further investigation.