In vitro detection of iron overload in leukemia cells using o-phenylenediamine-derived carbon dots

Carbon nanoparticles have emerged as highly effective sensors for detecting metal ions within cells in recent years. Phenylenediamine is well known as a starting material used to synthesize carbon dot nanoparticles. This study investigates the synthesis and application of o-PD CDs derived from o-phenylenediamine using a microwave method, focusing on their selectivity towards ferric iron (Fe³⁺) and their potential as fluorescent probes in leukemia cell lines. Physical and chemical characteristics of the oPD CDs show that the surface of the nanoparticles has redox-active functional groups and an average size of 7.6 nm. The fluorescence properties depict a characteristic absorption peak at 290 nm and 420 nm and maximum fluorescence emission at 570 nm. Initial selectivity experiments confirmed the specificity of o-PD CDs towards Fe³ ⁺, correlating with the cellular storage of excess iron in its ferric state. The fluorescence intensity of o-PD CDs was evaluated in leukemia cells (HL-60 and Jurkat) incubated with ferrous ammonium sulfate (FAS). Results demonstrated a concentration-dependent decrease in fluorescence with increasing iron concentration. Notably, a significant increase in fluorescence intensity was observed in HL-60 cells treated with higher FAS concentrations (200 and 400 µM), suggesting a potential relationship with cell death. HL-60 cells were exposed to varying ethanol concentrations to explore this phenomenon and analyzed via flow cytometry following incubation with o-PD CDs. Comparative analysis of the fluorescence profiles between HL-60 and Jurkat cells revealed a distinct difference, attributed to the insusceptibility of Jurkat cells to ferroptosis, a form of iron-dependent cell death, unlike HL-60 cells. These findings suggest that o-PD CDs can serve as effective fluorescent probes for detecting iron-related cellular changes and highlight their potential utility in distinguishing between different leukemia cell lines based on their susceptibility to ferroptosis. • o-phenylenediamine carbon dots (oPD CDs) selectively detect Fe 3+ ions. • oPD CDs detect iron overload in cell. • o-PD CDs as Fluorescent Probes for Iron-Related Cellular Changes. • Sensitivity of the oPD CD nanoparticle to ethanol-induced cell death.