Ascorbic Acid Nano-Dots with ROS Scavenging Properties for High Contrast Fluorescence Imaging

L-ascorbic acid (AA) is a hydrophilic, non-toxic, and ROS scavenger. Nano-formulation approaches yield nano-probes with excellent aqueous solubility, low toxicity, biocompatibility, and antioxidant activity. Herein, L-AA was used as carbon source for synthesis of CDs. AA-CDs were synthesized by one step-hydrothermal method, which exhibited strong absorption peak at 340 nm and emission peak at 420 nm. XRD confirmed amorphous nature of AA-CDs. These AA-CDs were biocompatible and also showed negligible toxicity against fungal pathogen ( Candida albicans ). Further, cellular uptake of AA-CDs was determined by monitoring their internalization into the microbial cells. AA-CDs showed best internalization in 60 minutes. Confocal microscopy images show internalized AA-CDs in the fungal cells, which is visible as bright blue fluorescence inside the cells. We conclude that AA-CDs is eco-friendly and biocompatible nano-probe for bioimaging.