Green synthesis of carbon dots using expired agar for a label-free fluorescence signal-amplified detection of ferric ion utilizing oxalate functionalization

Novel fluorescent (FL) ag-oxCDs are derived from expired agar and oxalate. ag-oxCDs are selective for Fe 3+ ions detection (LOD ∼ 75 μM) via FL “turn ON” mechanism. FL nanosensor based on agar biomass with upscale potential is developed herein.