Use the correlations for the thermophysical properties of nanofluid to find out the values and add new material in fluent database which contains those thermophysical properties value.

Thank you Salehin. But in DPM, I am adding a solid material along with the properties. Base fluid is pure water which is already present in FLUENT database. So according to you if I add or modify property values, then it will be single phase model. But in DPM it is two phase model. So how FLUENT will calculate properties?

First, do the simulation using only with pure water. After getting the steady state condition, turn on Species transport and in mixture material keep the pure water only. Then, spray the solid material using "droplet" and add water as the evaporating species.