News (2017-02-07)

 

Photoswitchable catalysis by a nanozyme mediated by a light-sensitive confactor

 

Simona Neri, Sergio Garcia Martin, Cristian Pezzato, Leonard Prins

 

J. Am. Chem. Soc. 2017, DOI:10.1021/jacs.6b12932 (click here)

 

The activity of a gold nanoparticle-based catalyst can be reversibly up- and down-regulated by light. Light is used to switch a small molecule between cis- and trans-isomers, which inhibit the catalytic activity of the nanoparticles to different extents. The system is functional in aqueous buffer, which paves the way for integrating the system in biological networks.

 

 

 

 

News (2017-01-23)

 

Transient self-assembly of molecular nanostructures driven by chemical fuels

 

Flavio della Sala*, Simon Neri*, Subhabrata Maiti, Jack L.-Y. Chen, Leonard Prins

 

Curr. Opin. Biotech. 2017, DOI: 10.1016/j.copbio.2016.10.014 (free download here until March 13)

 

Over the past decades, chemists have mastered the art of assembling small molecules into complex nanostructures using non-covalent interactions. The driving force for self-assembly is thermodynamics: the self-assembled structure is more stable than the separate components. However, biological self-assembly processes are often energetically uphill and require the consumption of chemical energy. This allows nature to control the activation and duration of chemical functions associated with the assembled state. Synthetic chemical systems that operate in the same way are essential for creating the next generation of intelligent, adaptive materials, nanomachines and delivery systems. This review focuses on synthetic molecular nanostructures which self-assemble under dissipative conditions. The chemical function associated with the transient assemblies is operational as long as chemical fuel is present.

 

 

News (2016-11-03)

 

Reversible electrochemical modulation of a catalytic nanosystem

 

Flavio della Sala, Jack L.-Y. Chen, Simona Ranallo, Denis Badocco, Paolo Pastore, Francesco Ricci, Leonard Prins

 

Angew. Chem. Int. Ed. 2016, 55, 10737 (link)

 

A catalytic system based on monolayer-functionalized gold nanoparticles (Au NPs) that can be electrochemically modulated and reversibly activated is reported. The catalytic activity relies on the presence of metal ions (Cd2+ and Cu2+), which can be complexed by the nanoparticle-bound monolayer. This activates the system towards the catalytic cleavage of 2-hydroxypropyl-p-nitrophenyl phosphate (HPNPP), which can be monitored by UV/Vis spectroscopy. It is shown that Cu2+ metal ions can be delivered to the system by applying an oxidative potential to an electrode on which Cu0 was deposited. By exploiting the different affinity of Cd2+ and Cu2+ ions for the monolayer, it was also possible to upregulate the catalytic activity after releasing Cu2+from an electrode into a solution containing Cd2+. Finally, it is shown that the activity of this supramolecular nanosystem can be reversibly switched on or off by oxidizing/reducing Cu/Cu2+ ions under controlled conditions.

 

 

 News (2016-11-03)

 

Dynamic nanoproteins: self-assembled peptide surfaces on monolayer protected gold nanoparticles

 

Sergio Garcia Martin, Leonard Prins, Chem. Comm. 2016, 52, 9387 (link)

 

Here, we demonstrate the formation of dynamic peptide surfaces through the self-assembly of small peptides on the surface of monolayer protected gold nanoparticles. The complexity of the peptide surface can be simply tuned by changing the chemical nature of the added peptides and the ratio in which these are added. The dynamic nature of the surface permits adaptation to changes in the environment.

 

 

 

 

 

News (2016-05-05)

 

Dissipative self-assembly of vesicular nanoreactors

 

Subhabrata Maiti, Ilaria Fortunati, Camilla Ferrante, Paolo Scrimin, Leonard Prins, Nature Chem. 2016, 8, 725 (link)

 

Dissipative self-assembly is exploited by nature to control important biological functions, such as cell division, motility and signal transduction. The ability to construct synthetic supramolecular assemblies that require the continuous consumption of energy to remain in the functional state is an essential premise for the design of synthetic systems with lifelike properties. Here, we show a new strategy for the dissipative self-assembly of functional supramolecular structures with high structural complexity. It relies on the transient stabilization of vesicles through noncovalent interactions between the surfactants and adenosine triphosphate (ATP), which acts as the chemical fuel. It is shown that the lifetime of the vesicles can be regulated by controlling the hydrolysis rate of ATP. The vesicles sustain a chemical reaction but only as long as chemical fuel is present to keep the system in the out-of-equilibrium state. The lifetime of the vesicles determines the amount of reaction product produced by the system.

 

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