Hello Everyone, been a long time since I last posted ,  I have been busy and also, I post comments in the computers forum so maybe you dont know me here.
But I need help right now, and I hope someone here can provide it,
I am working on a project to test the feasibility of creating an infrared PH indicator,
I don't know how feasible it is  but I know that colour changes in conventional indicators are caused by electrons moving from a more confined state to a delocalised state and hence, the energy difference corresponds to the photons of light emmited.
If the energy difference is low enough, photons can be emitted in the infrared range of the spectrum.
But how feasible?

I was wondering how you can have an infra red PH indicator. First, you must understand that PH is the -ve log of Hydrogen ion concentration and that's simply put. To measure the PH of any substance, it must be in solution (aq) for the ions to dissociate, this does not usually cause emission of photons except when the ions are excited and that can only be by introduction of heat which may or may not be in the infra red wavelenght. For any measurement in the infra red region, the substance must be hot enough to generate the infra red and the amount of heat generated will not have any relationship with the concentration of hydrogen or hydroxyl ion.
Conclusively, infra red devices will not measure PH values, since there's no relatoonship between concentration of Hdrogen/hydroxyl ion which PH is all about and heat which infra red represents.
I stand to be corrected though so hit me if you think so.

yes