In-situ green synthesis of copper tannic acid framework in the presence of graphene quantum dots: Improved colloidal and antibacterial properties

This work reports the preparation of a copper tannic acid MOF (CuTA) and graphene quantum dot (GQD) nanocomposite, GQD/CuTA, by a simple, environmentally friendly, and inexpensive method with exceptionally enhanced antibacterial properties. To end this, GQDs were first fabricated from citric acid using a neoteric, simple and straightforward hydrolysis approach and followed by they effectively anchor MOF nanoparticles (CuTA) by a green hydrothermal in situ synthesizing method. The constructed GQD/CuTA nanomaterials were characterized and validated using XRD, FT-IR, TEM, DLS, UV-vis, and PL techniques. Significant antibacterial activity against E. coli bacteria for both CuTA and GQD/CuTA (0 CFU/mL) and S. aureus bacteria for CuTA and GQD/CuTA (300 and 40 CFU/mL) was observed for the GQD/CuTA nanocomposite. The MTT assay showed good cytocompatibility for the GQD/CuTA nanocomposite against human dermal fibroblast cells (HFF-2). The result suggests that the synthesized GQD/CuTA nanocomposite with improved colloidal and antibacterial properties has the potential to be used as a safe photoluminescent nanoplatform with strong antimicrobial activity.