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.