Synthesis of green fluorescent carbon quantum dots from the latex of Ficus benghalensis for the detection of tyrosine and fabrication of Schottky barrier diode

Abstract

In this article, a facile and straightforward approach has been designed for the preparation of fluorescent green carbon quantum dots (G-CQDs) from the latex of Ficus benghalensis as the carbon source and polyethyleneimine as the nitrogen source. Various instrumental techniques such as transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) were employed to characterize G-CQDs. Interestingly, the as-prepared CQDs exhibited green fluorescence with a 41.2% quantum yield and showed excitation-dependent emission. The G-CQDs were applied as a fluorescent probe for the selective and sensitive detection of tyrosine (Tyr) with a detection limit of 0.13 μM. Furthermore, to explain the quenching mechanism, a fluorescence lifetime experiment was performed. In addition to this, the detection of Tyr was performed in milk samples. Based on their semiconducting properties, the synthesized G-CQDs were effectively applied to fabricate a Schottky barrier diode on an indium doped tin oxide (ITO) substrate. On the whole, this work is a novel illustration of the demanding optoelectronic device application of G-CQDs.