pH sensitive photoconductor based on poly(para-phenylene-vinylene)

A pH sensitive device based on poly(p-phenylene-vinylene) (PPV) in a coplanar electrode configuration is demonstrated. An increase in dark- and photocurrent of a thin (25–30 nm) poly(p-phenylene-vinylene) upon exposure to aqueous solutions is observed. The change in photocurrent is monitored as a function of pH. A roughly linear variation of the photocurrent with pH is observed between pH values of 4.5–9.5. The results are reversible and reproducible.