Bifunctional nanoparticle assemblies: photoluminescent and nitric oxide photodelivering monolayer protected platinum clusters

Abstract

In this contribution the design and fabrication of bifunctional, photoresponsive hybrid metal nanoparticle assemblies is reported. Integration of tailored porphyrin and NO photodonor units into ca. 1 nm carboxy-terminated platinum induces the formation of particle nanoassemblies of ca. 10 nm, which are quite soluble in aqueous solution at physiological pH and exhibit a bichromophoric behavior. Direct monitoring of NO through an ultrasensitive NO electrode demonstrates that the nanoparticles are stable in the dark but supply NO at nanomolar level in a way exclusively regulated by light excitation. Besides, the typical red fluorescence arising from the porphyrin centers in the nanoassembly is not quenched extensively, offering a useful tool for mapping the localization of the nanoparticles in bio-environments. Overall these nanohybrids represent appealing bright point sources of NO to be tested in biological research in the perspective of practical application in the emerging field of nanomedicine.

Dual‐Function Multilayers for the Photodelivery of Nitric Oxide and Singlet Oxygen

“…A quasi‐monotonic reflection enhancement upon compression, as a result of the average surface density growth, accompanied by an essentially unchanged profile is observed. This finding is of particular relevance since it suggests that the twisted conformation of the nitrogroup of 1 , which is crucial to trigger the NO release,10a,f is retained even at high surface pressure.…”

Nitric oxide release: Part I. Macromolecular scaffolds

“…In a subsequent report, a bifunctional NO release macromolecular scaffold was synthesized with mapping capacity via photoluminescence. 35 A thiol-derivatized porphyrin and the NO photodonor ligand were immobilized on the Pt surface via place exchange with some of the carboxy ligands. Neither the NO-releasing nor porphyrin ligand influenced the photobehavior of the other when attached to the Pt surface.…”

Light-controlled nitric oxide delivering molecular assemblies

“…These hybrid nanoassemblies exhibit a combination of indispensable requisites for biological applications, such as ultrasmall sizes, water solubility and thermal stability under physiological conditions, photoactivation with low energy light, excellent biocompatibility and appreciable photoinduced tumor cell mortality. 44,45 The same approach was used to create bifunctional MPCs combining NO photorelease with photoluminescence, 46 a very important feature for mapping the particles localization in bio-environments. Such MPCs incorporate some porphyrin units as fluorogenic units at the nanoparticles surfaces in addition to the NO photodonor.…”