While making AgNPs by using Plant extracts and AgNO3 (1mM concentration in 100 ml Distilled water), the quantity of Nanoparticles obtained after centrifugation is very less (less than 1 mg). How can I increase the quantity of the Nanoparticles? Also I wanted to know that if nanoparticles, in liquid form, can be used for the analysis through Electron Microscopy? Also, through what methods can one obtain AgNPs in dried/ powdered form?