Synthesis of Water Dispersible Fluorescent Carbon Nanocrystals from Syzygium cumini Fruits for the Detection of Fe3+ Ion in Water and Biological Samples and Imaging of Fusarium avenaceum Cells.

Abstract

In this work, water dispersible fluorescent carbon nanocrystals (NCs) were synthesized by a simple, green and low cost hydrothermal method using Syzygium cumini (jamun) as a carbon source at 180°C for 6h. The average size of carbon NCs was found to be 2.1±0.5nm and shown bright blue fluorescence when excited at 365nm under UV lamp. The carbon NCs were characterized by spectroscopic (UV-visible and fluorescence, Fourier transform infrared and dynamic light scattering) and high resolution transmission electron microscopic techniques. The quantum yield of carbon NCs was found to be ~5.9% at 438nm emission wavelength when excited at 360nm. It was noticed that none of the metal ions quenched the fluorescence intensity of carbon NCs at 438nm except for Fe3+, indicating the formation of Fe3+ ion-carbon NCs complexes. The linear range was observed in the concentration range of 0.01-100μM with the corresponding detection limits of 0.001μM, respectively. Furthermore, the carbon NCs were used as probes for imaging of fungal (Fusarium avenaceum) cells.