ChemSystemsChem最新文献

Stimuli-responsive, optically-active colloidal systems are convenient signal transducers capable of monitoring environmental changes at the nanoscale. We report on the coupling of chemo-thermal cycloaddition reaction with temperature-sensitive, DNA-coated gold nanoparticles. We found that the concentration of chemical fuel, dictating the temperature of the mixture, is a primary ingredient in controlling the extent of the reversible clustering of gold nanoparticles. Our results show that rational coupling of chemical and colloidal systems can open up new possibilities in tracking the change of local temperature using aggregation/redispersion of nanoparticles.

The front cover artwork is provided by BoekhovenLab at TU Munich. The image shows an energy landscape of kinetically trapped chemically fueled supramolecular fibers, which reminds of a mountain landscape. Read the full text of the Research Article at 10.1002/syst.202200035.

The Front Cover represents an energy landscape of kinetically trapped chemical-fueled fibers, which reminds of a mountain landscape. Our work unravels how tuning the kinetic trapping in chemical-fueled self-assemblies can recover dynamic instabilities, such as microtubule-like growth and shrinkage. This opens the door to the creation of new adaptive nanotechnologies. More information can be found in the Research Article by Job Boekhoven and co-workers.

The quest to understand life and recreate it in vitro has been undertaken through many different routes. These different approaches for experimental investigation of life aim to piece together the puzzle either by tracing life's origin or by synthesizing life-like systems from non-living components. Unlike efforts to define life, these experimental inquiries aim to recapture specific features of living cells, such as reproduction, self-organization or metabolic functions that operate far from thermodynamic equilibrium. As such, these efforts have generated significant insights that shed light on crucial aspects of biological functions. For observers outside these specific research fields, it sometimes remains puzzling what properties an artificial system would need to have in order to be recognized as most similar to life. In this Perspective, we discuss properties whose realization would, in our view, allow the best possible experimental emulation of a minimal form of biological life.

Hydrogen ion autocatalytic reactions, especially in combination with an appropriate negative feedback process, show a wide range of dynamical phenomena, like clock behavior, bistability, oscillations, waves, and stationary patterns. The temporal or spatial variation of pH caused by these reactions is often significant enough to control the actual state (geometry, conformation, reactivity) or drive the mechanical motion of coupled pH-sensitive physico-chemical systems. These autonomous operating systems provide nonlinear chemistry's most reliable applications, where the hydrogen ion autocatalytic reactions act as engines. This review briefly summarizes the nonlinear dynamics of these reactions and the different approaches developed to properly couple the pH-sensitive units (e. g., pH-sensitive equilibria, gels, molecular machines, colloids). We also emphasize the feedback of the coupled processes on the dynamics of the hydrogen ion autocatalytic reactions since the way of coupling is a critical operational issue.

The catalytic action of invertase generates bilayer asymmetry that stabilises membrane curvature. The driving mechanism for the generation of membrane curvature by invertase is investigated using giant unilamellar vesicles (GUVs). The invertase cleaves the sucrose in the exterior compartment, thereby creating a sugar asymmetry across the bilayer membrane that is measured for GUV membranes consisting of the lipid Dioleoylphosphatidylcholine (DOPC). Finally, the advantage of this method to control membrane curvature and to stabilize multi-sphere morphologies is demonstrated. The GUV system in the presence of invertase is beneficial as a tool to generate multiple on-demand compartments with more extended stability after the enzymatic activity has established the asymmetry.

Systems chemistry represents a shift from studying molecules in isolation to studying the collective behavior of mixtures or ensembles of reacting and interacting molecules. This research direction provides new ways to build and understand collective chemical properties and emergent functions that are inaccessible using conventional, reductionist, chemistry approaches. This field exemplifies fundamental connections between chemistry and biology, and has the potential to give rise to completely new ways for chemists to approach and resolve wide-ranging issues related to all aspects of living systems, that themselves are complex systems. Short peptides, while simple in design, carry rich and versatile information encoded in sequence specific side-chain interactions, that makes it possible to access a high level of complex, information rich systems with emergent properties from Life's simplified building blocks. This review focuses on recent developments in the synthesis of complex adaptive systems based on peptides, where multiple components are designed to cooperatively interact, react and collectively adapt to their context.

The front cover artwork is provided by the Hartley group at Miami University. The image shows a cartoon of transient molecular cages generated through the action of a chemical fuel on macrocycles with pendant groups. The cages are able to bind ions. Read the full text of the Research Article at 10.1002/syst.202200016.

The Cover Feature shows puzzle pieces that initially change their shape, and consequently their interconnection, to eventually go back to their initial state, resembling the behavior of the components in a dissipative dynamic combinatorial library. Design by Daniele Del Giudice. More information can be found in the Concept by Gianfranco Ercolani, Stefano Di Stefano and co-workers.

The Front Cover illustrates the formation of molecular cages through the action of a chemical “fuel” on macrocyclic precursors. The cages exist for only a short time but are able to bind appropriate cations. More information can be found in the Research Article by C. Scott Hartley and co-workers.