Nitrogen-doped Carbon Dots from Hutai-8 Grape Skin and their Application in Hg2+ Detection

Abstract

Background:In recent years, environmental pollution and heavy metal pollution caused by rapid urbanization and industrialization have become increasingly serious. Among them, mercury (II) ion (Hg2+) is one of the highly toxic heavy metal ions, and its pollution comes from various natural resources and human activities. Therefore, people attach great importance to the development of analytical methods for effective analysis and sensitive detection of Hg2+.Objective:Using grape skin as a green and environment friendly carbon source to synthesize fluorescent carbon dots and to apply them in detecting the concentration of Hg2+in water.Methods:Using "Hutai No. 8" grape skin as a carbon source, fluorescent carbon dots were synthesized by a one-step hydrothermal method. The structure and fluorescent properties of the carbon dots were tested using TEM, XPS, XRD, and other characterization instruments, and their utilization on the detection of mercury ions in the actual water samples was explored.Results:The CDs had a particle size of about 4.8 nm and a spherical shape. There were N-H, C-N, C=O, and other functional groups on the surface. It was found that Hg2+has an obvious fluorescence quenching effect on CDs, and thus CDs fluorescence quenching method to detect the concentration Hg2+was established, and the detection limit was 3.7 μM, which could be applied to test the concentration of Hg2+in water samples.Conclusion:Using grape skin as a carbon source, fluorescent carbon dots were successfully synthesized by the hydrothermal method. Carbon dots were used to detect mercury ions in water, and a method for detecting mercury ions in actual water samples was established.