TPAresponsive
TPAresponsive refers to materials engineered to change their physical or chemical state in response to two-photon irradiation. The term is used across photochemistry, materials science, and bioengineering to enable selective activation at depth within scattering media using near-infrared light.
The activation relies on two-photon absorption, typically by chromophores with large two-photon cross-sections. When two photons
Design considerations include choosing chromophores with high δ values, incorporating photolabile protecting groups or thermally latent linkages,
Applications encompass fluorescence imaging and sensing with deep-tissue resolution, photopharmacology for spatially controlled drug activation, and
History and challenges: Early demonstrations appeared in the 1990s and 2000s as two-photon biology matured. Current
See also: two-photon absorption; photolabile protecting groups; photoswitchable compounds; photoresponsive materials.