Novel synthesis of fluorescent carbon dots from bio-based Carica Papaya Leaves: Optical and structural properties with antioxidant and anti-inflammatory activities

Fluorescent carbon dots (CDs) are prepared from a natural resource Carica Papaya Leaves, by sand bath method. The as-synthesized CDs optical and structural properties were characterized by UltraViolet-Visible, FT- IR, and fluorescence spectroscopy. Also the size, shape, and particle size distribution was studied using Transmission electron microscopy technique. These CDs were examined for biomedical applications like free radical scavenging activity using DPPH assay, antioxidant activity using phosphomolybdate assay, and in vitro anti-inflammatory activity using membrane stabilization protocol. The CDs exhibited excellent biological activities at lower concentrations and showed notable half-maximal effective concentration (EC50). The EC50 of free radical scavenging activity (27.6 μg/mL), antioxidant activity (23.00 μg/mL), and in vitro anti-inflammatory activity (15.52 μg/mL) signifies that CDs can be potential therapeutic agents.