Seeing stars

Scientists hailing from the University of Cambridge and Imperial College London have produced amazing microscopic star-shaped crystals with the aid of Diamond Light Source. It is hoped that the novel stars can be used as scaffolds in areas such as energy storage, molecular sorting, and catalysis.

Tiny nanostructures are an essential part of emerging technologies and although many types of nano-building blocks have been made in the past, they resulted in a limited array of structures. To overcome this, a team of scientists cleverly designed a new series of building blocks based on reorganised DNA. Their work, recently published in Nano Letters, looks set to change the future of nanostructures.

The breakthrough came with the formation of unique star-shaped pieces of DNA. Termed ‘C-Stars’, these fascinating little DNA networks could be fine-tuned to self-assemble into complex shapes and designs.

“Previous studies have produced a restricted range of crystals structures  due to restrictions in the shapes used or limited specificity,” explained Lorenzo Di Michele,  principal investigator of the study. “C-Stars overcome these limitations and allow us to create some quite beautiful structures.”

The crystals that Di Michele and his colleagues made with the C-Stars soaked up water like a sponge. “Because of this they produce a very small scattering, and would be quite impossible to detect without the brightness of a synchrotron source,” continued Di Michele. “The materials are also of a size that they require X-rays that can only be delivered by a synchrotron such as Diamond.”

Indeed, the crystals were successfully observed at Diamond’s I22 beamline, allowing the team to clearly visualise the complex nanostructures they had made with the C-Stars.

“This experiment was quite different to what we’ve done before,” said Andy Smith, beamline scientist on I22. “To be able to set up the experiment, image the crystals in the capillaries and produce the data so quickly was really pleasing.”

“The beamline support staff were incredibly helpful, both in setting up the experiment and helping us with data collection,” added Di Michele.

The scientists have recently returned to the I22 beamline at Diamond to continue looking at nanostructures of different shapes and sizes and they hope to begin turning their constructions into light sensors.

“There are plenty of important questions to ask – such as how quickly the crystals form in different temperatures and solutions – so we can optimise the process and create even larger crystals,” concluded Dr Di Michele. Watch this star-shaped space for more developments from the team.

Figure from cited paper below.

Nano Letters 2017 17 (5), 3276-3281
doi:10.1021/acs.nanolett.7b00980