Reversible Protonation of Porphyrinic Metal‐Organic Frameworks Embedded in Nanoporous Polydimethylsiloxane for Colorimetric Sensing

Abstract A fast and reversible switch between the neutral and protonated porphyrin forms inside a pliable porphyrinic metal–organic framework (MOF), enabled by reversible structural deformation is unveiled. This phenomenon is applied for the development of MOF‐polymer porous composites to reveal biogenic amines by color changes.