By Amy Brundeen

Nanodiamonds, are extremely tiny diamonds — only a few nanometers wide — used in drug delivery, sensors, and quantum computer processors and their size and consistency are vitally important to the success of their function.

Hao Yan, assistant professor of chemistry, and his research team have researched a novel way to grow nanodiamonds that are extremely small and uniformly sized without using explosives, which is how they have been created but require further modification of the nanodiamonds for consistent sizes to be useful. The novel method to produce these nanodiamonds will allow them to be more easily modified for various uses, such as replacing a single carbon atom with nitrogen, silicon, or germanium, among thousands of carbon atoms necessary for successful quantum computers and telecommunication devices.

“Many of the applications of nanodiamonds, particularly for drug delivery, depend sensitively on their sizes,” Yan says. “Making them smaller has two benefits. First, a smaller diameter means a larger specific surface area, thus higher capacity as a drug vehicle. Second, the smaller size eases the removal and excretion of these diamond particles and reduces their toxicity.”

The Yan group presented their research at the Spring 2022 American Chemical Society Meeting in San Diego. In a video interview, Yan and graduate student research assistant Tengteng Lyu described their uniform ultra-small nanodiamonds and the method for creating them using geochemistry-inspired synthesis.

Yan says the most critical and scientifically challenging step, is to make these ultrasmall diamonds fluorescent, which requires the incorporation of single-atom defects, known as ‘color centers,’ into the diamond lattice. 

“We hope that by pushing the boundary of precision chemistry under extreme environments, we can encode more functionalities into materials that are inaccessible in beakers and flasks,” he says.

Yan and his research group have patented their high-pressure, high-temperature technique and nanoscience. They are in conversation with collaborators who have the capabilities of producing nanodiamonds on a gram scale — similar to that of synthetic gemstone diamonds. They predict these diamonds will be available to researchers within the next two years for drug delivery and mechanical applications.

“We believe these harvested nanodiamonds will have tremendous impacts on technology and the opportunities are infinite,” Yan says.