“…1c, with 3-aminopropyldimethylethoxysilane (APDMES), followed by a derivative of 8-hydroxypyrene-1,3,6trisulfonic acid (HPTS), 8-acetoxy-pyrene-1,3,6-trisulfonyl chloride. 29,49 Frequently applied as a light-triggered source of protons in various studies, 29,48,49,51,[57][58][59] HPTS has a pK a of $7.3 at the ground state and is exceptionally more acidic when photoexcited, with pK a as low as $0.4. Previous uorescence experiments veried that the photoactivated pH decrease is conned to the surface, depending on the light intensity of the source.…”