Abstract

Graphene Quantum Dots (GQDs) represent a new generation of ultra-small, photostable and highly biocompatible fluorescent nanomaterials suitable for biomedical imaging. The present study explores the potential of laboratory-synthesized GQDs for ophthalmic bio-imaging and retinal cell tracking applications. GQDs were synthesized using a green, bottom-up carbonization method and characterised by UV–Vis spectroscopy, photoluminescence, TEM, FTIR, Raman spectroscopy and Zeta potential measurements. The strong blue fluorescence, narrow emission peak and excellent aqueous stability of GQDs make them suitable for ocular environments. In-vitro biocompatibility was evaluated using ARPE-19 (retinal pigment epithelial) cell lines, showing over 90% cell viability up to 200μg/mL concentration. Confocal microscopy confirmed the internalization of GQDs into retinal cells with strong cytoplasmic localization and no morphological damage. These findings indicate that GQDs may serve as promising candidates for realtime retinal cell tracking, early diagnosis of retinal degeneration and non-invasive ophthalmic imaging. Further in-vivo studies are recommended to validate their full therapeutic and diagnostic potential.

Keywords:Graphene quantum dots; Ophthalmic imaging; Retinal cell tracking; Fluorescence nanoprobes; Nanobiotechnology; Biocompatibility