Silicon nitride has been widely used as a pH sensing insulator for ion sensitive field effect transistors employed in complementary metal oxide semiconductor integrated chemical sensors. in this paper, we report a new method for making a silica surface highly sensitive to pH. The photochemical vapor deposition technique can be considered as a suitable approach for aminating the silica surface or the amorphous silicon surface in order to increase its sensitivity to pH. The pH responses of the obtained membranes are Nernstian, indicating a change in the surface sites. X-ray photoelectron spectroscopy analysis and wettability measurements have been used to characterize the surface site binding after deposition.