Maybe SEM is not suitable, TEM may be required depending on the required resolution. In both cases you could try to use a drop of your (diluted) material on a TEM grid with carrier film (carbon, Si nitride, Si oxide).

Thanks for the advice Dr. Stefan Baunack, the reason why I will analyze it in the SEM is because it is the tool that my advisor has given me access to so far, so I wanted to be able to have the most success in the session that I will have with the microscope. I was interested in doing EDS on my sample and I don't know, for that, it is enough to drop a drop of my diluted sample because I understand that for that it will be necessary to use the backscattered electrons.

What do you expect from EDS?

It's not the best choice for very light elements like carbon and there's a lot of carbon around (contamination layer, carbon carrier film).

I see, what I expected from the EDS was to be able to confirm that it really had quantum dots by looking at the chemical composition of the sample and noting that it really had carbon. After having purified the sample, I thought that in this way I could see that the fluorescence was due to to carbon elements and not to another existing phenomenon, this is because I still have doubts if the fluorescence that my sample presents is really due to the formation of quantum dots.

Once I have taken FESEM analysis for CQDs.

I have followed this tech -

The gold sputtering step helps to neutralize the charge on the sample, which results in a better quality image.