RESUMO
Two bolaamphiphilic quadrupoles built from a fluorene core conjugated with azine endgroups were designed and successfully used to stain GUV membranes. Their quadrupolar character induces both a shift of the pKa values close to the physiological pH and large two-photon absorption responses (i.e. over 1000 GM for acidic forms). As such they hold promise as ratiometric two-photon pH probes for monitoring slight variations of pH near cell membranes using two-photon excitation in the NIR region.
Assuntos
Corantes Fluorescentes/química , Fosfolipídeos/química , Prótons , Corantes Fluorescentes/síntese química , Concentração de Íons de Hidrogênio , Estrutura MolecularRESUMO
We report the design and synthesis of a nano-container consisting of mesoporous silica nanoparticles with the pore openings covered by "snap-top" caps that are opened by near-IR light. A photo transducer molecule that is a reducing agent in an excited electronic state is covalently attached to the system. Near IR two-photon excitation causes inter-molecular electron transfer that reduces a disulfide bond holding the cap in place, thus allowing the cargo molecules to escape. We describe the operation of the "snap-top" release mechanism by both one- and two-photon activation. This system presents a proof of concept of a near-IR photoredox-induced nanoparticle delivery system that may lead to a new type of photodynamic drug release therapy.
