One-step microwave-assisted green synthesis of luminescent N-doped carbon dots from sesame seeds for selective sensing of Fe(III)

Abstract

The present study focuses on the green synthesis of nitrogen-doped carbon dots (C.dots) from sesame seeds using microwave pyrolysis method. The C.dots obtained were characterized and extensively studied using transmission electron microscopy (TEM), UV/ visible spectroscopy, fluorescence spectroscopy and Fourier transform infra-red spectroscopy (FTIR) techniques. The results indicated the presence of highly fluorescent, aqueous soluble and significantly photostable C.dots with a quantum yield of 8.02%. The average size distributions of C.dots were found to be 5 nm. These C.dots were effectively applied as a selective sensor for Fe(III) as the fluorescence intensity was significantly quenched with increasing metal concentrations. The limit of detection (LOD) was found to be 2.56 μM of Fe(III). This study demonstrates a low cost, environmental friendly and waste recyclable synthetic method for preparation of C.dots and its application as a selective Fe(III) sensor.