It may indicate different things but mostly it means 2 species of NPs (based on size) are forming which could be due to difference in nucleation patterns they are going while in the biological system...

A graphical plot will be helpful to see where the peaks are located. Is one peak at very small sizes (e.g. < 2 nm) or very large sizes (e.g. 5000 nm)?

@ Chandra I think you may be jumping to conclusions without seeing the plot or data.....

Thank You @ Dr. Alan F Rawle Sir,

Silver nanoparticles DLS (Measurement) graph

OK, thank you. What did the report and expert advice say? Was the data quality good?

Alan, yes I haven't seen the data.

What's your opinion about this Alan? To me it looks like heterogeneous nucleation. Although further analysis would be required to confirm.

Thank You @ Dr. Alan F Rawle and Dr Chnadra K Dixit Sir,

Data results quality was good, Poly Dispersity Index (PDI) (

I await the Quality report and Expert Advice that's provided in the Zetasizer software. I assume 5 measurements were taken in a row and the data are stable. Another useful calculation to do is a Stokes' Law one to determine what size of (relatively dense) Ag can remain in free suspension.

@ Dr Alan F Rawle Sir,

Thank you so much for your guidance and help.

OK, I see nothing obviously incorrect with your measurement. Have you measured any standard sample such as a 100 nm latex?

You may wish to consider creating a new folder. This one says Record 513. Your default folder will take some time to load. Not a good idea to put huge numbers of records in an individual folder. The sample is relatively dilute (attenuator on position 9) but there are plenty of normalized counts.

We can now speculate as to the possible reasons for 2 populations in the sample. One possibility is aggregation and agglomeration. Is the result stable over time?

Hello Bipin,

your data look good and are probably reproducible. Here are the potential reasons that could lead to your observation:

• aggregation (of the small particles, i.e. if you expect your gold to be 20nm)
• surfactant in addition to the large gold (i.e. if you expect your gold to be 150nm)
• rotational diffusion in addition to translational diffusion (see http://www.materials-talks.com/blog/2014/11/17/tips-tricks-for-nanoparticle-characterization/#gold )

If you filter the sample through 20nm and there is still gold: it's aggregated. If no gold left but still size peak: it's surfactant. If no gold and no size peak: rotation.