Interface Flexibility: New Key to Nanoscale Network Design

In a breakthrough that could reshape the design of molecules at the nanoscale, EPFL scientists in Switzerland have identified 'interface flexibility' as a crucial property governing the self-organization of molecules into crystalline supramolecular networks. The study, published in *Nature Chemistry*, unveils that the rigidity at the point where molecules connect is more critical than the strength of chemical bonds. Maartje Bastings, head of the Programmable Biomaterials Lab (PBL) at EPFL, explains that hexagonal network structures are common in nature, citing beehives as an example. The research team, including members from the Laboratory for Bio- and Nano-Instrumentation (LBNI) led by Georg Fantner, used nanoengineered DNA strands to examine factors controlling network formation. The team modulated the flexibility of DNA star 'arms' and observed that rigid arms formed stable hexagonal networks, while flexible arms did not. Simulations showed rigid arms were more likely to align in a parallel shape, facilitating connections. "The interface where two molecules come together must be rigid; if one is flexible, there's a lower chance the molecules will stay connected," Bastings stated. The discovery has potential applications in cellular nanotherapies, spintronics, and the prevention of diseases like Alzheimer's. By controlling interface flexibility, scientists could design proteins for self-assembly or disrupt undesirable networks, such as amyloid plaques. Bastings envisions this work impacting the creation of next-generation electronics through the self-assembly of nanoscale networks.