Evaluation of Carbon-Based Fluorescent Nanoparticles as Potential Photosensitizers: Biological and Electrochemical Responses in Cancerous and Healthy Cell Models

Photodynamic therapy (PDT) induces cell damage via reactive oxygen species (ROS) secondary to photosensitizers. This study evaluates Carbon Dots (CDs) as photosensitizing agents by assessing cell viability and electrochemical behavior in healthy epithelial (HEKa) and breast cancer (MCF-7) cell lines, before and after ultraviolet (UV) irradiation. Three nanoparticles (CDs, $\mathbf{G d}^{\mathbf{3} \boldsymbol{+}} \boldsymbol{:} \mathbf{C D}$, and $\mathbf{G d}^{\mathbf{3} \boldsymbol{+}} \boldsymbol{/} \mathbf{Y b}^{\mathbf{3} \boldsymbol{+}} \boldsymbol{:} \mathbf{C D} \boldsymbol{)}$ were synthesized via microwaveassisted method and characterized. A $\mathbf{5 0 ~} \boldsymbol{\mu} \mathbf{g} / \mathbf{m L}$ concentration was chosen based on pre-irradiation MTT assays. Irradiation reduced cell viability and altered impedance, especially in CDs-Treated cells, suggesting membrane damage and photosensitization. Results support the potential of CDs in PDT through combined viability and electrochemical analyses.