I don't see why not., though I am much more knowledgeable about organic than inorganic chemistry. I would go about this by obtaining a very pure sample of your metal nanoparticle (maybe purify by small scale preparative HPLC or column chromatography), and dissolve in a solvent that absorbs only at very short wavelengths (water or acetonitrile), and see if there is a difference in the spectra between that and the solvent blank. 

@ Austen..Thank you for your help. Actually I want methodology through which we can determine the concentration of NPs by their difference in their absorption peaks. How to actually calculate that.. 

You Need an extintion coefficient for your nanpaticles. But in my opinion You may take in account, rhat there is also scattering.