Biogenic synthesis of carbon quantum dots from garlic peel bio-waste for use as a fluorescent probe for sensing of quercetin.

Highly fluorescent and water-soluble carbon quantum dots (CQDs) were synthesized from the bio-waste source of garlic peels (renovation of bio-waste into bio-asset) using a controlled carbonization method. Synthesized CQDs were characterized by various analytical methods and explored as a fluorogenic probe for the recognition of quercetin (QT). Ultraviolet-visible (UV-vis) result shows an absorption maximum at 275 nm attributed to the conjugation of C=C and C=O of CQDs and demonstrates a blue emission in the range 330-410 nm. Selectivity was performed with various biomolecules, except for QT, all others do not exhibit any considerable change in the fluorescence of CQDs. On the interaction with QT, emission was completely quenched due to Förster energy transfer (FET), confirming the high selective to QT. Effect of pH, sensitivity, and stability studies displayed excellent results under optimized conditions. The limit of detection (LOD) fluorescent probe was found to be 6.73 μM. Our approach may suggest a new platform for the development of quick and low-cost CQDs-based sensors for environmental and biological purposes.