Green Synthesis of Bimetallic PtCu‐Modified Carbon Quantum Dots With Enhanced Photocatalytic Activity and Promising Biological Potential

ABSTRACT

Researching new antimicrobial agents is of great importance due to the issue of antimicrobial resistance, which has become more important than many diseases today. In this context, PtCu@CQDs were synthesized by applying a green, cheap, and easy hydrothermal method using Achillea millefolium ( A. millefolium ) extract. Achillea millefolium extract, which has different medicinal properties, has been used as a precursor for CQD synthesis by the hydrothermal method and as a reducing agent for Pt and Cu ions. The synthesized PtCu@CQDs were characterized using UV–vis, FL spectroscopy, FTIR, XRD, and TEM. In XRD analysis, the average coherent crystal region (crystallite) size of PtCu@CQDs, calculated using the Scherrer equation, was determined to be approximately 2.75 nm, while TEM analysis revealed that the nanostructures exhibited a spherical morphology in the 3–10 nm range. PtCu@CQDs exhibited 88.59% antioxidant activity against DPPH at a concentration of 500 µg/mL. PtCu@CQDs exhibited 99.99%, 99.99%, 80.76%, and 99.99% antibacterial activity against E. coli , S. aureus , B. subtilis , and K. pneumoniae bacteria, respectively. Furthermore, the photocatalytic activity of PtCu@CQDs was tested to be 89.94%. The results obtained show that PtCu@CQDs can serve as antibacterial and antioxidant agents in the field of health and will have a wide potential for use in applications.