Biomimetic sheets offer improved chemical functionality

A two-dimensional biomimetic material with customisable properties able to self-assemble at an oil-water interface has been developed at the Lawrence Berkeley National Laboratory. The research could pave the way to designing peptoid nanosheets of increasing structural complexity and chemical functionality for a broad range of applications. Like their natural counterparts, peptoids fold and twist into distinct conformations that enable them to perform specific functions. “Peptoid nanosheets properties can be tailored with great precision, and since peptoids are less vulnerable to chemical or metabolic breakdown than proteins, they are a highly promising platform for self-assembling bio-inspired nanomaterials” said Ron Zuckermann from the Molecular Foundry. Scientists used vibrational sum frequency spectroscopy to probe the molecular interactions between molecules as they assembled at the oil-water boundary. Measurements revealed that peptoid polymers adsorbed to the interface are highly ordered; this order is influenced by interactions between neighbouring molecule. “We can literally see the polymer chains become more organised the closer they get to one another,” said Zuckermann. The technology could be applied to chemical sensors and separators, or in more effective drug delivery vehicles. “The production of peptoid nanosheets in microfluidic devices means that we should soon be able to make combinatorial libraries of different functionalised nanosheets and screen them on a very small scale,” Zuckermann said. “This would be advantageous in the search for peptoid nanosheets with the molecular recognition and catalytic functions of proteins.” The group, who published their work in Proceedings of the National Academy of Sciences, are now investigating adding chemical reagents or cargo to the oil phase and exploring their interactions with the peptoid monolayers that for during the assembly process. The work, funded by the Department of Energy Office of Science and Defense Threat Reduction Agency, builds on previous work by the group which saw them develop peptoid nanosheets that form between air and water. Assembly and molecular order of two-dimensional peptoid nanosheets at the oil-water interface