I produce a protein nanoparticle complex,but in fe-sem, I see a few number of nanoparticles,maybe 2 or 3 ,however the color of suspension solution is quite milky and this is a sign of nanoparticles formation. how do i increase the number of nanoparticles in the form of fe-sem?(I do not dilute the suspension solution for the preparation of fe-sem at all)