In fact, it is difficult to assume the molecular ratio in water-insoluble particle and water-based biomolecule system due to the aggregation in aq. liquid sample; Simply "in theory", you may calculate the ratio if you know the molecular information such as molecular weight, mole, or size/density of nanoparticles. You can get it in a plenty of info by searching websites, even somewhere over researchgate. Eventually, it requires soluble condition, purified, and optimized functionalization for any further applications.
Why don't you change any other polymers which are water-soluble ?