Preparation of Auricularia auricula doped carbon-nitrogen quantum dots and their application in detecting heavy metal ions

Abstract

This paper uses Auricularia auricula as the biological matrix material to synthesize carbon quantum dots (CQDs) with blue fluorescence by one step hydrothermal method. The characterization results by transmission electron microscope (TEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) indicate that CQDs are spherical in shape with an average particle size of 6 nm. The surface of CQDs contains hydrophilic groups such as hydroxyl, carboxyl, and amino groups, which have good water solubility. At the same time, CQDs have good fluorescence stability and excellent selectivity and anti-interference properties towards Fe³⁺. They exhibit good linearity in the range of 3–40 μmol/L, with a detection limit of 0.28 μmol/L. CQDs have been used as probes for the detection of Fe³⁺ content in tap water and mineral water, and satisfactory results have been obtained. Therefore, this probe has broad application prospects.