Try a look at this (and the earlier references on slide 3). 

Nov 11th, 2008. Dispersion and nanotechnology  http://tinyurl.com/hpywsge

Your excellent question outlines some of the issues with dealing with the complexities of stabilizing nanoparticles. Another important thing to realize is that the surface in silver nanoparticles is actually Ag2O (oxide).  See:

September 2nd, 2015 Silver colloids and invisible ink

https://www.brainshark.com/malvern/vu?pi=560497681&b=1&tx=120486&c1=22

A typical capping agent should not be didentate or multidendate i.e., they should not have multiple metal chelating sites. If they do then it will result in aggregation.

But there is one more side to this, only multidentate ligands bring in specificity. And if you look at the examples you quoted all of them are multidentate and they are very specific to certain elements.

ok,but why multidenate are specific to any elements if they have multiple sites for coordination?and I thought that multidentate ligands are if use for stabiliziation over surfcce of metallic nanoparticls, these can be used for further functinalization.

Specificity is the ability of a mutlidentate ligand (in this case) to bind to one element. Specificity can come because of size restrictions if the individual ligands in a multidentate ligand are oriented favorably such that the size of the cavity is sufficient to accommodate an element of certain size only or also it could be due to differences in their binding strength (by having suitable conditions).

Yes, multidentate ligands can be used for functionalization but they can also bind to two different nanoparticles which leads to aggregation if the conditions are suitable.

Then that leads to the next important concept binding affinity. Every ligand has certain affinity for binding towards another element or nanoparticle. If the binding affinities of different ligands in a molecule are different then you could use them for different purposes such as stabilization of nanoparticles and additional functionalization.

But if the binding affinities of different ligands in a molecule are same then that can lead to aggregation to nanoparticles. You cannot do two different things like stabilization and functionalization with them.

Dear Aiman

There are different capping/stabilizing agents having different nature,sizes,electric and gripping abilities toward nanoparticles etc,similarly different elements(nanoparticles)behaves differently with different capping/stabilizing agents depends how charges are distributed on their surfaces,mono, di, or poly dentate,can be used but handling multi or poly dentat stabilizing agents have multiple active site hence cause aggregation of nanoparticles which increases size of nanoparticles to  500 nm to above 1000 nm, which is violation of nanotsim.

Regard 

Muhammad imran khattak 

Just an aside: the ISO and ASTM definitions of nanoparticle have particles with one or more dimensions in the 1 - 100 nm region.  Everything is nano, including the distance to the sun, if expressed in nm - doesn't mean it's a nanoparticle or material

ok, but what should do to stabilize Nanoparticles with multidentate ligands?

Choose a multidentate ligand with ligands of different binding affinities to the nanoparticle of your interest. Since the ligands have different binding affinities only one ligand will bind strongly to the nanoparticle and the other ligand will bind weakly. Choose the experimental conditions such that the weakly bound interaction is broken (e.g. pH change) and use this ligand for further functionalization.

thanks for for your answer, it would be very thankful if send me research articles over this issue, because i still donot understand , what I should exactly do  if I have to stabilize silver nanoparticles particularly, by the multi dentate ligand like arginine.

another question which I have, those nanoparticles which are stabilize by the help of flavinoids like catechin and disporoin or else, which have multiple hydroxyl groups in their structures at different positions , acts as a very good stabilizing agent , if hydroxyl groups present at one side of their structure are stabilizing the nanparticles than at the other side , they should interact wirth neighbiuring nanoparitcles and results in aggregation , but papers are not showing this.