Dear Ayokunle Adeniyi Adeloye ,

If your NP dispersion is homogeneous and you know the silver NPs concentration, it is straightforward dilution on volume or weight basis. In case you don't know the silver NPs concentration in the undiluted solution you have to determine that first. If there are no other non-volatile substances in the synthesis mixture, you could take a small sample and determine its solid fraction (taking a sample, weighing it, evaporating the solvent and weighing how much silver NP residue you have) or in case you do have non-volatiles in there, do an ash residue of the silver NPs dispersion.

Next, diluting is done by either volume or weight to the desired concentration based on what was present in the original synthesis dispersion.

One word of warning, you stated that you are doing an invivo experiment and want to use distilled water as diluent. Is that wise? Most biological systems have a fixed salt content and injecting distilled water is not advised. As diluent I would use something like 0.9 (wt/wt)% sodium chloride solution or even a suitable buffer to avoid disturbing the biological system you aim to use your silver NPs in.

Hope this helps, kind regards, Leo

If you know the concentration of your stock solution, then you can convert the number of moles of Ag into mass of Ag by multiplying with 107.8.

Then dilute accordingly to prepare the desired solution in ug/ml

Dear Ayokunle Adeniyi Adeloye , at first, you should pinpoint the concentration of your stoke Ag NPs dispersion. To this end, you can dissolve a small portion of the stoke dispersion in nitric acid and then measure the concentration of the resulting silver ions using ICP-OES or any other analytical method. The measured ug/ml concentration of silver ions equals that of silver nanoparticles. Not to mention, in order to determine the accurate concentration, you should take the volume of added nitric acid into account as well. After this step, you can dilute the stoke dispersion to your desired concentrations.

Best,

Thanks for your invaluable contributions!... I'm grateful