Biyomedikal ve optik uygulamalar için bitki aracılı sürdürülebilir nanomalzemeler

Plant-mediated nanomaterials have gained significant attention in biomedical and optical studies because of their biological and optical properties. For that reason, we focused on two different plant extracts (Hypericum perforatum and Peganum harmala) in biomedical and optical applications. In the first part of this thesis, we synthesized zinc oxide nanoparticles (ZnO NPs) using Hypericum perforatum via an environmentally friendly green synthesis method. Nanoparticles were characterized using UV-Vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) analyses. The anticancer effect of these nanoparticles was investigated against the human liver cancer cell (Hep-G2) with cell culture studies. Finally, the antibacterial activity of the ZnO NPs was studied. Cell viability studies demonstrated a NP dose-dependent inhibition of cell viability along with significant cytotoxic effects at higher concentrations. With this study, we showed that these ZnO NPs have extremely high potential as therapeutics for liver cancer treatment. In the second part of this thesis, we designed a paper-based color converter using Peganum harmala extract for solid-state lighting. Due to the high quantum yield of the plant extract in the solid state, fluorescent biomolecules from the plant extract were wrapped into crystal-based (sucrose and KCl crystals) and cellulose fiber-based (cotton pads and drying papers) matrices. Optical characterizations demonstrated high quantum efficiency in the fiber paper group. As a proof-of-concept demonstration, P. harmala extract embedded fiber paper was used as a color converter on an LED, and the device revealed a blue emission with a luminous efficiency of 21.9 lm Welect−1. The results showed that these environmentally friendly plant-based materials can replace the currently used color converters as their cost-effective and sustainable alternatives.