科学家成功创造金纳米粒子与病毒粒子混合体

Scientists have created a diamond-like lattice（晶格，格子） composed of gold nanoparticles and viral（病毒的） particles, woven together and held in place by strands¹ of DNA². The structure – a distinctive³ mix of hard, metallic⁴（金属的） nanoparticles and organic viral pieces known as capsids（衣壳） , linked by the very stuff of life, DNA – marks a remarkable⁵ step in scientists' ability to combine an assortment⁶（分类，混合物） of materials to create infinitesimal（无限小的） devices. The research, done by scientists at the University of Rochester Medical Center, Scripps Research Institute, and Massachusetts Institute of Technology, was published recently in Nature Materials.

While people commonly think of DNA as a blueprint⁷ for life, the team used DNA instead as a tool to guide the precise positioning of tiny particles just one-millionth of a centimeter across, using DNA to chaperone the particles.

Central to the work is the unique attraction of each of DNA's four chemical bases to just one other base. The scientists created specific pieces of DNA and then attached them to gold nanoparticles and viral particles, choosing the sequences and positioning them exactly to force the particles to arrange themselves into a crystal lattice.

When scientists mixed the particles, out of the brew⁸ emerged a sodium⁹ thallium crystal lattice. The device "self assembled" or literally¹⁰ built itself.

The research adds some welcome flexibility¹¹ to the toolkit that scientists have available to create nano-sized devices.

"Organic materials interact in ways very different from metal nanoparticles. The fact that we were able to make such different materials work together and be compatible in a single structure demonstrates some new opportunities for building nano-sized devices," said Sung Yong Park, Ph.D., a research assistant professor of Biostatistics and Computational Biology at Rochester.

Park and M.G Finn, Ph.D., of Scripps Research Institute are corresponding authors of the paper.

Such a crystal lattice is potentially a central ingredient to a device known as a photonic（光激性的） crystal, which can manipulate light very precisely¹², blocking certain colors or wavelengths¹³ of light while letting other colors pass. While 3-D photonic crystals exist that can bend light at longer wavelengths, such as the infrared¹⁴, this lattice is capable of manipulating visible light. Scientists foresee many applications for such crystals, such as optical computing¹⁵ and telecommunications, but manufacturing and durability¹⁶ remain serious challenges.

It was three years ago that Park, as part of a larger team of colleagues at Northwestern University, first produced a crystal lattice with a similar method, using DNA to link gold nanospheres. The new work is the first to combine particles with such different properties – hard gold nanoparticles and more flexible organic particles.

Within the new structure, there are actually two distinct forces at work, Park said. The gold particles and the viral particles repel¹⁷（击退，抵制） each other, but their deterrence¹⁸（威慑，妨碍物） is countered by the attraction between the strategically placed complementary strands of DNA. Both phenomena¹⁹ play a role in creating the rigid²⁰ crystal lattice. It's a little bit like how countering forces keep our curtains up: A spring in a curtain rod pushes the rod to lengthen²¹, while brackets（支架） on the window frame counter that force, creating a taut²²（拉紧的，紧张的） , rigid device.