<p>Folic acid-coated zinc ferrite (ZnFe₂O₄) nanoparticles were integrated into a polyvinyl alcohol (PVA) matrix through solution casting. The objective was to modify the properties of PVA at a minimal concentration of nanoparticles while preventing agglomeration. X-ray diffraction analysis confirmed the presence of the incorporated phases, and changes in the hydrodynamic size of the FA-ZnFe₂O₄ nanoparticles were observed via zeta sizing. Fourier transform infrared spectroscopy verified the presence of the folic acid coating. Ultraviolet–visible spectroscopy showed a redshift in optical absorption and notable alterations in the direct bandgap (5.44&#xa0;eV to 4.92&#xa0;eV). Furthermore, changes in the Urbach energy (0.48&#xa0;eV to 0.70&#xa0;eV), extinction coefficient (1.78 × 10⁻⁴ to 5.24 × 10⁻³ at 400&#xa0;nm), refractive index (1.18 to 2.64 at 270&#xa0;nm), and optical conductivity (2.88 × 10⁹ S⁻¹ to 1.34 × 10¹¹ S⁻¹ at 400&#xa0;nm) were documented. Additionally, frequency-dependent electrical analysis indicated an increase in the dielectric constant (1.02 to 3.8 at 1&#xa0;MHz), a decrease in the dielectric loss (5.39 to 2.99 at 10&#xa0;MHz), and an enhancement in AC conductivity (8.11 × 10⁻⁴ S m⁻¹ to 1.52 × 10⁻³ S m⁻¹). These films have potential applications in wide-bandgap UV-photodetectors and dielectric devices.</p> Graphical abstract <p></p>