Hi Jamir, ITO is soluble in acidic solutions, etching in the presence of an acid is unavoidable.

Phil Denby thank you. I am trying now the basic conditions. bUt the result was not so good.

What exactly are you trying to do, EPD can mean many things!

In general your Au and SiO2 will be much less reactive than the ITO so you will always deferentially react of etch the ITO first.

Phil Denby , actually my work is to Au@SiO2 core shell nanoparticles on ITO glass by Electrophoretic deposition method.So i dispersed the NPs in ethanol solution and using 2 electrode DC supply. I used acidic conditions but echhing happened. I used NaOH for basic conditions(pH-10), but the deposition is very less. So i am thinking how to deposit successfully without damage to the ITO glass.

Ahh I see, ITO is really not suitable for this, as, as well as etching you are likely to carry out reduction on the ITO and change it to a dark layer.

Is there a reason you have to use a transparent conductor? You can for example buy very cheap PCBs from china and have them gold plated - see PCBway.com

We used some ourselves:

https://www.youtube.com/watch?v=mMB43x_JEUg

@phil denby, yes we have to use only TCO substrates for optical applications. Either ITO or FTO. But ITO is more preferable. I will try NH4OH basic conditions.

I think you will have to rethink your strategy, with any form of ionic solution and applied DC voltage you will oxidise or reduce the transparent oxide coating. The TCO is a very carefully balanced material with metalic doping of an oxide material, any chemical reaction will seriously shift the stochiometry of the layer and ruin the conductivity and or optical properties. You might consider doing reflection optical studies with an inert metallic coating.

Phil Denby , Yes sir . I used Poly(diallyldimethylammonium chloride) Solution for charging the Au@SiO2 surface with +ve charge and did cathodic deposition. but result was same , etching of ITO glass. Even it have no H+ ion.