Synthesis and Functionalization of Carbon Quantum Dots with Riboflavin for Photodynamic Therapy Applications
Varun Batra, Karthickraj Sudalaimuthu Mohan, Jaiganesh Ramamurthy, Sesuraj Balasamy, Ashok K. Sundramoorthy, Ramanarayana BoyapatiBackground:
Photodynamic therapy (PDT) is an emerging treatment modality that employs photosensitizers activated by light to generate reactive oxygen species (ROS). Carbon quantum dots (CQDs) exhibit excellent photostability, tunable optical properties, and high biocompatibility, making them promising candidates for PDT. Functionalization with riboflavin may further enhance ROS generation and therapeutic potential.
Aim:
To synthesize and evaluate riboflavin-functionalized CQDs (CQD-RIB) as potential photosensitizers for PDT against peri-implantitis-associated pathogens.
Materials and Methods:
CQD-RIB was synthesized and characterized using UV–Vis spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy, and energy dispersive X-ray spectroscopy (EDX). Antimicrobial activity was assessed by agar diffusion assays against
Results:
Ultraviolet–visible spectra showed characteristic absorption at 270–300 nm with a shoulder around 400 nm, indicating successful riboflavin functionalization. FTIR confirmed hydroxyl, carbonyl, and aromatic functional groups, whereas XRD demonstrated an amorphous carbon structure with graphitic characteristics. Antimicrobial testing revealed concentration-dependent inhibition zones up to 17 mm at 100 µg/mL. MTT analysis showed high cell viability (>100%), indicating excellent biocompatibility.
Conclusion:
Riboflavin-functionalized CQDs demonstrate strong antimicrobial activity and favorable biocompatibility, supporting their potential as photosensitizers for PDT.