Improving Fluorescence and Colloidal Stability of Carbon Dots through Dialysis Purification

Carbon Dots (CDs) are fluorescent nanoparticles ranging from 1 to 10 nm, known for their unique optical and electronic properties, such as strong fluorescence, good biocompatibility, and low toxicity. These features make them promising for biomedical and neuroscientific applications, including bioimaging, drug delivery, and photodynamic therapy. In this study, CDs were synthesized from Glycine max using a microwave-assisted hydrothermal route, with a focus on optimizing purification steps and evaluating the impact of dialysis on fluorescence and colloidal stability. To stabilize surface sites and enhance quantum yield, the CDs were functionalized with polyethylene glycol 400. Samples were divided into three groups: dialysis for 24 h, 48 h, and the retained fraction. Characterizations were performed using fluorescence, UV-Vis, and FTIR spectroscopies, as well as Dynamic Light Scattering (DLS) and Zeta Potential analysis. The 48 h dialyzed sample showed the highest emission and absorption intensity, with functional groups confirmed by FTIR. DLS analysis indicated suitable particle sizes, while Zeta Potential results revealed good colloidal stability. These findings demonstrate the potential of the synthesized CDs for use in biological and neuroscientific systems requiring high optical quality and nanoparticle stability