Seeing Viruses in a New Light

Detecting viruses in a nanohole fiber (Source: Heraeus)

Detecting viruses in a nanohole fiber (Source: Heraeus)

Viruses can be the cause of life-threatening infections such as flu or intestinal diseases. As viral diseases increase and spread, the clear detection and definite identification of adaptable pathogens is becoming increasingly important. Virological diagnostics offer a number of elaborate options. These include scanning electron or fluorescence microscopy, methods that require preliminary steps such as dyeing or spatial fixation. However, marking a virus with a dye changes its properties.

Scientists at the IPHT, in cooperation with others at Heraeus Quarzglas, Harvard University and Leiden University, have succeeded in the marker-free and nondestructive detection of viruses with dimensions smaller than 20 nm. They did so using a fiber with made of quartz glass from Heraeus with a nanohole with a diameter of 200 nm that extends along the entire fiber. This advance makes it possible to observe viruses in their natural environment without manipulation. Initial measurements with test viruses have already been completed at Harvard and Leiden.

Heraeus Quarzglas worked with an IPHT research team to develop the fiber. Stefan Weidlich, physicist at Specialty Fiber Optics Research & Development at Heraeus Quarzglas, is pleased with the achievement: “Our application is distinguished by the fact that we put the viruses into quartz glass – one of the purest technical materials manufactured today. The fiber itself conducts light almost perfectly, without scattering it. But as soon as the light encounters the virus, some of it is diffracted. This allows very rapid observations with an extremely limited background. As a result, the movement of a virus can be observed and recorded within a period of several seconds.”

For Stefan Weidlich, the use of the nanohole fiber to examine viruses is just the first of many applications. “We envision other fields of application in medicine, in life sciences and in sensor technology. For example, it could be used to measure very valuable small particles in a liquid, such as pharmaceuticals, because the sample volumes required for the nanohole fibers are so minimal.” (Source: Heraeus / IPHT)

Reference: S. Faez et al.: Fast, Label-Free Tracking of Single Viruses and Weakly Scattering Nanoparticles in a Nanofluidic Optical Fiber, ACS Nano, 9 (12), 2015; DOI: 10.1021/acsnano.5b05646

Links: Huygens-Kamerlingh Onnes Laboratory, Leiden Institute of Physics, Leiden University, The Netherlands Ÿ• Research Group Fiber Sensors, Leibniz Institute of Photonic Technology (IPHT), Jena, Germany • Specialty Fiber Optics Research & Development, Heraeus Quarzglas GmbH & Co. KG, Hanau, Germany • Department of Physics, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, United States

Speak Your Mind