(367f) Polydopamine Coatings of g-C3N4 Structures with Improved Biomedical Properties

Graphitic carbon nitride (g-C₃N₄) is an intriguing nanomaterial capable of photoconductive fluorescence under UV-visible light. Here, g-C₃N₄ structures were prepared from melamine and were modified by coating with polydopamine p(DA). The coating of g-C₃N₄ with p(DA) was done 1, 3, and 5 times repetitively as (p(DA)@g-C₃N₄). The successive multiple p(DA) coatings of g-C₃N₄ were confirmed with FT-IR spectra as the peak intensity at 1512 cm^-1 for N-H bending was increased as the number of p(DA) coatings was increased. Also, the increase in weight loss% values of p(DA)@g-C₃N₄ structures with the increasing number of p(DA) coatings at 500 ^oC from TGA thermograms affirmed the coating amount. The band gap value of g-C₃N₄, 2.72 eV, decreased to 0.87eV after the 5^th coating with p(DA). The isoelectric point (IEP) of pristine g-C₃N₄ was found to be 4.0. and decreased to 3.94 and 3.91 for p(DA)1@g-C₃N₄ and p(DA)3@g-C₃N₄, respectively which are close to each other. On the other hand, the IEP of p(DA)5@g-C₃N₄ was determined as pH 5.75. The cytotoxicity of both g-C₃N₄ and p(DA)@g-C₃N₄ on the L929 fibroblast cell line was compared. Also, the antioxidant properties of p(DA)@g-C₃N₄ were assessed with total phenol content (TPC), total flavonoid content (TFC), iron(III) ions reducing capacity (FRAP), and the iron(II) chelating capacity (ICC) were investigated. Finally, the potential usage of prepared PDA@g-C₃N₄ structures to inhibit the α-glucosidase enzyme was tested.

Acknowledgments

The financial support from Canakkale Onsekiz Mart University Scientific Research Commission (COMU-BAP: FBA-2022-4117) is greatly acknowledged.