Plasmon excitation of supported gold nanoparticles can control molecular release from supramolecular systems

Perylene-Grafted Silicas: Mechanistic Study and Applications in Heterogeneous Photoredox Catalysis

A mechanistic study is herein presented for the use of heterogeneous photocatalysts based on perylene moieties. First, the successful immobilization of perylene diimides (PDI) on silica matrices is demonstrated, including their full characterization by means of electronic microscopy, surface area measurements, powder XRD, thermogravimetric analysis, and FTIR, ²⁹ Si and ¹³ C solid-state NMR, fluorescence, and diffuse reflectance spectroscopies. Then, the photoredox activity of the material was tested by using two model reactions, alkene oxidation and 4-nitrobenzylbromide reduction, and mechanistic studies were performed. The mechanistic insights into their photoredox activity show they have promising dual photocatalytic activity for both organic oxidations and reductions.

A versatile, immobilized gold catalyst for the reductive amination of aldehydes in batch and flow

A process for the reductive amination of aldehydes in continuous flow catalyzed by gold nanoparticles immobilized onto mesoporous silica has been developed.

Visible and Near-Infrared Plasmon-Mediated Molecular Release from Cucurbit[6]uril Mesoporous Gated Systems

Several hybrid mesoporous materials were synthesized in order to obtain a drug/cargo delivery system in which it is possible to control both the start and rate of the cargo release via surface plasmon (SPR) excitation. The successful incorporation of a thermoresponsive gate based on a cucurbit[6]uril-hexamethylene diamine (CB6-Hex) host-guest complex conferred the system with the desired "zero" premature release. This feature combined with the incorporation of gold nanorods (AuNR) and gold nanoparticles (AuNP) capable of acting as a heat source upon SPR excitation enabled a controlled cargo release system active to green and NIR irradiation. The results obtained prove that it is possible to disassemble the CB6-Hex gate complex in a few minutes using either green or NIR irradiation in order to activate the system and start the release process (that can take hours), as well as to further control the diffusion of Naproxen as a model drug.