The Effect of Charge on Zn Tetra Morpholine Porphyrin Conjugated to Folic Acid-Nitrogen Doped Graphene Quantum Dots for Photodynamic Therapy Studies

Zinc tetra morpholine porphyrin (complex 2), and its quaternized derivative (complex 3) were synthesized and conjugated to folic acid nitrogen doped graphene quantum dots (FA-NGQDs) through stacking to study their photodynamic therapy (PDT) efficacy. photophysiochemical properties of complexes 2, 3, and their conjugates (2-FA-NGQDs, 3-FA-NGQDs) were studied. It was found that complex 3 had higher of 0.56 compared to complex 2 with of 0.24, and respective composites: 3-FA-NGQDs had higher compared to 2-FA-NGQDs. The PDT studies were conducted for nanoparticles (FA-NGQDs), complexes (2, 3), and respective composites (2-FA-NGQDs, and 3-FA-NGQDs) using MCF-7 breast cancer cell. Dark toxicity of all compounds was above 90% which is negligible. At a higher concentration of 40 µg/mL all the compounds showed higher PDT efficacy, with 3-FA-NGQDs having lower cell viability of 28% compared to all other compounds.