The invention provides a bicolor
silicon ball doped with PEI carbon dots and bipyridyl
ruthenium, a preparation method of the bicolor
silicon ball and a
copper ion determination
system.The preparation method comprises the steps that
citric acid, polyethyleneimine and redistilled water are stirred and dissolved and then subjected to a pre-reaction, an obtained gelatinous substance is kept heated, the redistilled water is added in several times for a reaction, and a reaction solution is obtained; a hydrophilic carbon
quantum dot (PEI-CQDs) solution wrapped by PEI is obtained; the preparation method comprises the following steps: mixing tetraethoxysilane,
ammonia water, water and
ethanol for reaction, adding a bipyridyl
ruthenium solution for reaction, and then adding a PEI coated hydrophilic carbon
quantum dot solution for reaction to obtain the PEI
carbon dot and bipyridyl
ruthenium doped bicolor
silicon sphere. According to the invention, PEI-CQDs and
bipyridine ruthenium Ru (bpy) 3 < 2 + > are doped into
silicon dioxide nanoparticles,
red fluorescence of Ru (bpy) 3 < 2 + > is used as a
background color, and bicolor colorimetric detection of
copper ions can be realized by combining an internal filtering effect of Cu < 2 + > and PEI-CQDs. A
fluorescence signal of PEIQDs-Ru-SiO2 has obvious response to
copper ions and has good selectivity, and the PEIQDs-Ru-SiO2 can be used for
visual detection of Cu < 2 + >.