Hi Ijuo,

Few things that need to be taken into account are:

1. Calibrate the scale properly before analyzing each image.

2. Identify areas with isolated particles so that you do not bias your statistics to higher value by measuring aggregates (even smaller).

3. Measure as many particles as possible (more than 100) with minimal human error. Better zoom in or use higher magnification images for measurement.

If these things are done carefully, the average sizes measured from ImageJ can be relied upon.

Thanks,

Thanks a lot @Ashis Kar

Ijuo Abawulo Godwin Are your nanoparticles spherical or nearly spherical? If yes, for better accuracy, you can also calculate the area of the circle and calculate the radius. Due to aggregation of dried samples, and absence of water, SEM/TEM images depict a different diameter than the hydrodynamic diameter presented by DLS. However, SEM/TEM represents the morphology well. The rest I agree with Ashish Kar