GREEN SYNTHESIS OF N-DOPED CARBON NANODOTS FROM WALNUT HUSK AND THEIR APPLICATION FOR DETECTION OF FE3+ ION IN SERUM AND IN WATER SAMPLES.

Abstract

Carbon Nano dots (CNDs) with a size bellow 10 nm is a recently developed class of carbon-based nanomaterial’s, initially N-NCDs were incidentally discovered as a fluorescent impurities by scrivens in 2004 during the refining process of single walled carbon based nanotubes, the carbon nano dot’s received a tremendous debate because of their low cytotoxicity, environmental friendly, excellent biocompatibility, high photo stability and good water solubility. And having a wide range of application in various field such as fluorescent sensing, photo catalysis, biological imaging, opto- electronic devices, medical diagnosis, and in drugs delivery etc. In this particular work we have formed green nitrogen doped carbon nano dot’s (N-CNDs) by utilizing walnut husk as a carbon precursor and ethylenediamine as a nitrogen precursor (Nitrogen doping enhance the optoelectronic properties and quantum yield of N-CNDs) with the use of an eco – friendly and simple hydrothermal method with a quantum yield of 45.6 %. the characterizations of N-CDs was done by applying different spectroscopic techniques, for example transmission electron microscopy (TEM) measurements show quasi – spherical shape of N-CNDs having an average particle of 3.1nm in diameter, FT – IR, RmS,  X – rays diffraction, and X – rays photoelectron spectroscopy were used to analyzed the structural composition of nitrogen doped carbon nano dots (N-CNDs), the as prepared N-NCDs shows high fluorescent property with a very strong emission fluorescence spectra at 470nm upon excitation at 387nm. It was research observed that N-CNDs show high sensitivity and selectivity towards iron ion sensing in aqueous medium, so we have used it for the detection of Fe³⁺ in real samples such as in human blood serum and in tap water. A good liner relationship ranging from 0 – 600 µM were observed between Fe³⁺ ion concentration and Fo/F, with correlation coefficient (R²) 0.9943 µM, the LOD (limit of detection) were 0.084 µM which is better than most of the reported values.