3.1 Intracellular GSH changes
The one-dimensional fluorescence spectra of GSH (Figure 3) showed that
the emission wavelengths of GSH detected by CQDs as probes were all
around 465 nm; from 0 to 14 d, the measured GSH content changed slowly
and increased significantly after 14 d, reaching the maximum on day 50.
The two-dimensional correlation of GSH content was calculated, and the
synchronous and asynchronous two-dimensional correlation fluorescence
spectra of GSH were obtained. It can be seen that there is only one
autocorrelation peak on the main diagonal, and there is no cross peak
outside the main diagonal. The excitation wavelengths of CQDs as probes
are all 370 nm, and the synchronous fluorescence change graph of GSH is
completely synchronous, i.e. all peaks of the same substance belong to
synchronous change. Since there is no obvious interference in the
system, no cross peaks exist outside the main diagonal. In the
two-dimensional asynchronous correlation fluorescence spectrogram, an
asynchronous cross peak appeared at 465 nm outside the main diagonal,
and excitation at 370 nm would get an emission peak at 465 nm, and the
distribution of GSH content at different stages was clear.