Laser partical size analysis is a cheap method to reach this aim. But be careful, before test you must diapers the nano particles within a solvent.

Interesting question

The best way to measure nanoparticle size is to use HRTEM. The method my be not very cheap but it gives good result. For known materials such as Si for example physical parameters may help. Such as from the energy gap dependence on particle size since the energy gap in semiconductors has a direct dependence on nano particl size particularly for sizes less than 15nm

for particles in a liquid the liquid colour relates particle size

Interesting

Dynamic Light Scattering (DLS) is a proven way to quicly characterize the native particle size distribution. Works down to about 20nm as I recall. Some commercially available units also perform zeta potential analysis.

Hello Salsabeel kareem Burhan !

The best way to analyze the particles morphology (i.e. shape, size and geometry) and particle size distribution is to carryout High resolution Transmission electron microscopy (HRTEM).

Cold you tell me more about DVC , please

Drop cast your particles and observe with SEM or TEM. For SEM some coating may be needed. Standard technique.

Thank you for all who answered

BY Using many high resolution techniques such as FESEM, HRTEM and AFM