Photodynamic ion sensor systems with spiropyran: photoactivated acidity changes in plasticized poly(vinyl chloride)

We aim to introduce photoactivated optical ion sensors based on a triggered ion exchange process as novel dynamic tools. The quantification of the acidity change upon photoactivation of spiropyran within an organic membrane phase during photo-excitation is described here for the first time, suggesting a large pK(a) change of more than 6 orders of magnitude.