I would like to calculate the pH of a certain bacteria species before after an experiment. I was reading about the pH cell of bacteria and I found out about Bacterial Intracellular pH which I different than the pH level outside the cell. I plan to measure the pH Outside of the cell as a method to represent the pH of the bacteria.
I am soaking a piece of paper into a bacteria solution (bacteria + media). After that, I am exposing the piece of paper to different parameters. I would like to measure the slight change in pH if any, due to the exposure. In sum, I would like to measure the pH level of the bacteria on paper before and after exposing it to different parameters to compare the change.
For before and after exposure, I will submerge the paper in a neutral liquid suck as DI water or a new sample of the bacteria media for an hour and measure the pH of the solution. Is that a valid method to measure the pH change or do I have to use a dye to see the color of the cell to quantify the pH?