Naproxen release from carbon dot coated magnetite nanohybrid as versatile theranostics for HeLa cancer cells

Nanohybrid magnetite carbon dots (Fe₃O₄@CDs) were successfully synthesized to improve their applicability in multi-response bioimaging. The nanohybrid was prepared via pyrolysis and further loaded with naproxen (NAP) to promote drug delivery features. The characterization of the synthesized Fe₃O₄@CDs demonstrated the existence of Fe₃O₄ crystals by matching with JCPDS 75-0033 and its narrow size distribution at 11.30 nm; further, FTIR spectra confirmed the presence of Fe-O groups, C-O stretching, C-H sp², and C-O bending, along with dual-active fluorescence and magnetic responses. The nanohybrids also exhibit particular properties such as a maximum wavelength of 230.5 nm, maximum emission in the 320-420 nm range, and slight superparamagnetic reduction (Fe₃O₄: 0.93620 emu per g; Fe₃O₄@CDs: 0.64784 emu per g). The cytotoxicity assessment of the nanohybrid revealed an excellent half-maximal inhibitory concentration (IC₅₀) of 17 671.5 ± 1742.6 μg mL^-1. Then, the incorporation of NAP decreased the cell viability to below 10%. The kinetic release properties of NAP are also confirmed as pH-dependent, and they follow the Korsmeyer-Peppas kinetics model. These results indicated that the proposed Fe₃O₄@CDs can be used as a new model for theranostic treatment.