Nav: Home

AD alloyed nanoantennas for temperature-feedback identification of viruses and explosives

April 01, 2019

Scientists of Far Eastern Federal University (FEFU) in collaboration with colleagues from Far Eastern Branch of Russian Academy of Sciences (FEB RAS), ITMO University and Swinburne University of Technology (Australia) developed a method for efficient mass production of silicon-germanium fully alloyed nanoantennas. On their basis, optical biosensory platforms and next-generation chemical sensors for fast and accurate tracing of viruses, pollutions, explosives, etc. at low concentrations are expected to appear. Related paper was published in Nanoscale.

To fabricate all-dielectric (AD) optical nanoantennas, scientists proposed a facile technology based on a temperature-assisted dewetting of commercial silicon-on-insulator (SOI) substrates at 800°C in high vacuum. Such treatment of SOI substrate leads to the formation of silicon nanodrops, which can be used as optical nanoantennas, amplifying the signals from various adsorbed molecules. Scientists have shown that the deposition of Ge in the process of SOI dewetting allows producing alloyed nanoparticles with unique properties. Such nanoantennas allow to identify adsorbed molecules as well as to access and control the local temperature at high accuracy and resolution in the process of measurement.

"It's very useful to know the local temperature because in the process of measurement both the nanoantennas and the adsorbed analyte molecules are exposed with intense laser radiation which causes their heating. At the same time, most organic molecules degrade at rather low temperatures around 130-170°C, i.e. in the process of measurement one can simply burn them up before getting a useful signal. Such useful temperature-feedback modality cannot be realized with plasmonic nanoantennas commonly used to design biosensors. All-dielectric nanoantennas provide a reliable way to achieve this feature as the measured characteristics spectrum of the analyte molecules already contains all information required to determine the local temperature of the "nanoantenna-molecule" system." Said Aleksandr Kuchmizhak, a researcher in the FEFU Center for Virtual and Augmented reality.

"By controlling the concentration of germanium in the alloyed silicon nanoparticles, one can tailor their properties; in particular, control their resonant optical characteristics, as well as the light-to-heat conversion efficiency. This is very useful for studying of various chemical processes and reactions induced by laser radiation." Reported Evgeny Mitsai, a researcher at Institute of Automation and Control Processes and Institute of Chemistry, FEB RAS.

The scientist emphasized that by using all-dielectric nanoantennas one can study in details the temperature-mediated effects in laser-induced chemical reactions at high temporal resolution. Moreover, all-dielectric nanoantennas remain chemically non-invasive, i.e. their presence -- unlike the presence of the plasmonic-based nanoantennas -- causes no effect on the studied analytes and reactions.

Until today, the mass production of all-dielectric nanoantennas was difficult. Commonly used electron-beam lithography was too expensive and time-consuming. The technology proposed by FEFU scientists in collaboration with their colleagues from the FEB RAS, ITMO University, universities of Australia and Tunisia, allows getting over this limitation.
-end-
FEFU run a priority research project "Materials" engaged a group of talented physicists, chemists, biologists, and materials scientists, most of which are young scientists under 35 years old. Among other things, researchers actively study novel promising nanomaterials and technologies for next-generation sensory systems as black silicon and laser-textured PTFE.

The study was supported by Russian Science Foundation (RSF), grant 18-79-10091

Far Eastern Federal University

Related Technology Articles:

The science and technology of FAST
The Five hundred-meter Aperture Spherical radio Telescope (FAST), located in a radio quiet zone, with the targets (e.g., radio pulsars and neutron stars, galactic and extragalactic 21-cm HI emission).
AI technology could help protect water supplies
Progress on new artificial intelligence (AI) technology could make monitoring at water treatment plants cheaper and easier and help safeguard public health.
Transformative technology
UC Davis neuroscientists have developed fluorescence sensors that are opening a new era for the optical recording of dopamine activity in the living brain.
Do the elderly want technology to help them take their medication?
Over 65s say they would find technology to help them take their medications helpful, but need the technology to be familiar, accessible and easy to use, according to research by Queen Mary University of London and University of Cambridge.
Technology detecting RNase activity
A KAIST research team of Professor Hyun Gyu Park at Department of Chemical and Biomolecular Engineering developed a new technology to detect the activity of RNase H, a RNA degrading enzyme.
Taking technology to the next level
Physicists from the ARC Centre of Excellence for Ultrahigh bandwidth Devices for Optical Systems (CUDOS) developed a new hybrid integrated platform, promising to be a more advanced alternative to conventional integrated circuits.
How technology use affects at-risk adolescents
More use of technology led to increases in attention, behavior and self-regulation problems over time for adolescents already at risk for mental health issues, a new study from Duke University finds.
Hold-up in ventures for technology transfer
The transfer of technology brings ideas closer to commercialization. The transformation happens in several steps, such as invention, innovation, building prototypes, production, market introduction, market expansion, after sales services.
The ultimate green technology
Imagine patterning and visualizing silicon at the atomic level, something which, if done successfully, will revolutionize the quantum and classical computing industry.
New technology detects COPD in minutes
Pioneering research by Professor Paul Lewis of Swansea University's Medical School into one of the most common lung diseases in the UK, Chronic Obstructive Pulmonary Disease, has led to the development of a new technology that can quickly and easily diagnose and monitor the condition.
More Technology News and Technology Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.