Imaging nano-particle self-assembly provides blueprint for molecular machines

Research lead

Scientists at Glasgow University, UK, and Bielefeld University, Germany, have imaged the self-assembly of nanoparticles, an advance which they say provides a blueprint for building designer molecular machines.

In a study reported in the journal Science, the researchers describe an experiment that enabled them to observe molecules being constructed around what appeared to be a transient template cluster.

The experiment involved the construction of a flow reactor system for the assembly of the nano-particles under dynamic ‘flowing’ conditions. This allows self-assembly to be examined in a new way at the nano-level, giving rise to unprecedented mechanistic information and unmasking the complexities of molecular self-assembly.

Self-assembly describes the process by which objects form a particular arrangement without any external manipulation.

During the experiment, the researchers observed the self-assembly of molybdenum oxide wheel molecules around an intermediate structure in the centre of the wheel, which they found to be the template or scaffold used to construct the larger molecule. Following completion of the molybdenum oxide wheel molecule, which is just 3.6 nanometres in diameter, the template was ejected, freeing it to repeat the process.

Leroy Cronin of Glasgow’s Department of Chemistry, who devised and led the study, said, “This advance is very important since in the construction of molecular nano-objects we must rely on self-assembly where the nano-scale objects builds itself.”

This process is almost impossible to understand or control using current step-wise chemical synthesis approaches. “Therefore, understanding the assembly process is vital if we are to create a new range of functional nano-objects,” Cronin said.

“This discovery could lead the way for the designed assembly of a whole range of precisely-defined nano-particles with applications in electronics, medicine, and catalysis.”

Cronin added, “Not only do we get to image self-assembly for the first time using this type of flow system, this discovery will allow us to devise new types of blueprint that could allow the assembly of a whole new class of designer nano-particles".