Closed Mechanoelectrochemical Cycles of Individual Single‐Chain Macromolecular Motors by AFM

Shi, Weiqing; Giannotti, Marina I.; Zhang, Xi; Hempenius, Mark A.; Schönherr, Holger; Vancso, G. Julius

doi:10.1002/anie.200702387

Cited by 63 publications

(47 citation statements)

References 29 publications

(35 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This performance allows PFS to serve as a candidate for the realization of a single-macromolecular motor. [77] As shown in Figure 11, ethylene-sulfide-end-capped PFS was immobilized on a gold substrate and the other terminal was physically adsorbed on an atomic force microscopy (AFM) tip, establishing a molecular bridge between the AFM tip and the gold substrate. Upon application of an electrochemical potential, the PFS could be oxidized into its cationic form, and the single chain of PFS lengthened because of the electrostatic repulsion between the oxidized ferrocene centers along the chain.…”

Section: Redox Switchesmentioning

confidence: 99%

Tuning the Amphiphilicity of Building Blocks: Controlled Self‐Assembly and Disassembly for Functional Supramolecular Materials

2009

Self Cite

View full text Add to dashboard Cite

Amphiphilicity is one of the molecular bases for self‐assembly. By tuning the amphiphilicity of building blocks, controllable self‐assembly can be realized. This article reviews different routes for tuning amphiphilicity and discusses different possibilities for self‐assembly and disassembly in a controlled manner. In general, this includes irreversible and reversible routes. The irreversible routes concern irreversible reactions taking place on the building blocks and changing their molecular amphiphilicity. The building blocks are then able to self‐assemble to form different supramolecular structures, but cannot remain stable upon loss of amphiphilicity. Compared to the irreversible routes, the reversible routes are more attractive due to the good control over the assembly and disassembly of the supramolecular structure formed via tuning of the amphiphilicity. These routes involve reversible chemical reactions and supramolecular approaches, and different external stimuli can be used to trigger reversible changes of amphiphilicity, including light, redox, pH, and enzymes. It is anticipated that this line of research can lead to the fabrication of new functional supramolecular assemblies and materials.

show abstract

Section: Redox Switchesmentioning

confidence: 99%

Tuning the Amphiphilicity of Building Blocks: Controlled Self‐Assembly and Disassembly for Functional Supramolecular Materials

2009

Self Cite

View full text Add to dashboard Cite

show abstract

“…The technique has been widely used to determine equilibrium thermodynamic parameters by mechanically driving probed molecules out of equilibrium at various loading rates (16,(20)(21)(22)(23)(24). To date, there have been very few investigations reported on wholly synthetic small molecules (31,(40)(41)(42)(43)(44), mainly because of the difficulty of preparing appropriate molecules that can be interfaced with single-molecule force spectroscopy techniques, but also because the size of the molecules implies that the rupture events occur at very small distances, in the range of 1 nm. Here we have probed donor-acceptor oligorotaxane foldamers, synthetic prototypes of molecular switches, by AFM-based dynamic force spectroscopy.…”

Section: Resultsmentioning

confidence: 99%

Dynamic force spectroscopy of synthetic oligorotaxane foldamers

Sluysmans

Devaux

Bruns³

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Wholly synthetic molecules involving both mechanical bonds and a folded secondary structure are one of the most promising architectures for the design of functional molecular machines with unprecedented properties. Here, we report dynamic single-molecule force spectroscopy experiments that explore the energetic details of donor-acceptor oligorotaxane foldamers, a class of molecular switches. The mechanical breaking of the donor-acceptor interactions responsible for the folded structure shows a high constant rupture force over a broad range of loading rates, covering three orders of magnitude. In comparison with dynamic force spectroscopy performed during the past 20 y on various (bio)molecules, the near-equilibrium regime of oligorotaxanes persists at much higher loading rates, at which biomolecules have reached their kinetic regime, illustrating the very fast dynamics and remarkable rebinding capabilities of the intramolecular donor-acceptor interactions. We focused on one single interaction at a time and probed the stochastic rupture and rebinding paths. Using the Crooks fluctuation theorem, we measured the mechanical work produced during the breaking and rebinding to determine a freeenergy difference, ΔG, of 6 kcal·mol −1 between the two local conformations around a single bond.AFM | single-molecule force spectroscopy | molecular machines | foldamers | equilibrium dynamics B iological molecular machines are known to operate out of their thermodynamic equilibrium to carry out specific tasks such as cargo transport performed by single myosins (1), or cell movements driven by flagella rotary motions (2). The work performed by these natural molecular motors is related to their dynamics in solution, and to the force exerted by the molecule to drive the relevant process in one direction. The invention of synthetic routes to wholly artificial molecular machines with highly precise and controlled architectures has led to the production of amazing molecules able to perform mechanical tasks (3-7). Their integration into materials such as metal-organic frameworks (8) or polymer gels (9, 10) has been described recently. The resulting materials can experience a macroscopic change when each single machine is pulled out of its equilibrium state, as a result of an external stimulus, such as light irradiation or a change in solvent.Collecting information about the behavior of such molecules when driven out of their equilibrium is crucial for the design of more efficient molecular devices. Atomic force microscopy (AFM)-based single-molecule force spectroscopy (SMFS) has emerged as a very elegant technique to probe inter-and intramolecular forces as well as mechanical processes (11-16). By trapping individual molecules between a mechanical probe and a substrate, it is possible to apply an external force to drive them out of the equilibrium and perform very precise and controlled operations in one direction. For 20 y, AFM-based SMFS was used to unravel the behavior of natural biomolecules under mechanical load and has led to a d...

show abstract

“…This switching property has been shown to play a key role in changing the volume requirements of the individual PFS chains. [26] It is believed that oxidation of the Fe(II) electroactive centres manifests itself as a conformational change of the polymer chains owing to the presence of electrostatic repulsion between the charged electroactive centres, resulting in addressable structural changes for the overall material as switching takes place between the two states. Hence, this redox activity can be triggered by an external stimulus to address supramolecular architectures and to monitor the material's responsive behaviour.…”

Section: Doi: 101002/adma201103793mentioning

confidence: 99%

Redox‐Active, Organometallic Surface‐Relief Gratings from Azobenzene‐Containing Polyferrocenylsilane Block Copolymers

et al. 2012

View full text Add to dashboard Cite

show abstract

Closed Mechanoelectrochemical Cycles of Individual Single‐Chain Macromolecular Motors by AFM

Cited by 63 publications

References 29 publications

Tuning the Amphiphilicity of Building Blocks: Controlled Self‐Assembly and Disassembly for Functional Supramolecular Materials

Tuning the Amphiphilicity of Building Blocks: Controlled Self‐Assembly and Disassembly for Functional Supramolecular Materials

Dynamic force spectroscopy of synthetic oligorotaxane foldamers

Redox‐Active, Organometallic Surface‐Relief Gratings from Azobenzene‐Containing Polyferrocenylsilane Block Copolymers

Contact Info

Product

Resources

About