Synthesis, morphological, spectral and thermal studies for folic acid conjugated ZnO nanoparticles: potency for multi-functional bio-nanocomposite as antimicrobial, antioxidant and photocatalytic agent

The conjugations of ZnONPS with a biological surface-active substance, folic acid (FA), may achieve more biological activity and medical applications. Therefore, the current research was aimed to synthesis the ZnONPS then conjugated with FA by a facile chemical method. The morphological studies for free ZnONPS and ZnONPS@FA was performed using the (TEM), (SEM), (XRD), (EDX) and Zeta-potential. The spectral analyses were followed by UV–vis measurements and Photoluminescence (PL). The structural composition and conjugation strategies between ZnONPS and FA were observed by (FT-IR). The thermal stability was investigated using Thermo gravimetrical analysis (TGA). The antimicrobial efficacy and the minimum inhibitory concentration (MIC) were examined against 10 human pathogens. The NPS was investigated for photocatalytic degradation of methylene blue dye (MB). The antioxidant activity was detected. The results were showed nanocrystalline wurtzite possess quasi spherical NPS with size 16 nm (λmax = 373 nm, band gab 3.32 eV) after loading FA the sized increased by 2 nm with d spacing 0.3 nm. As FT-IR findings the FA and ZnONPS were linked via an amide bonding. The photo-degradation for MB after 180 min reached 82% and 85% for ZnONPS and ZnONPS@FA, respectively. The antioxidant activity for nanocomposite was enhanced as well as the antimicrobial for E. faecalis and others more than free NPS. The results of MIC and MBC values were ranged from16 to 256 μg mL−1 and 16 to 512 μg mL−1, respectively. In conclusion, we can conclude that incorporation of FA to NPS was enhanced its antioxidant and antimicrobial potential leading it to be promising in many biomedical and food packaging applications.