"We electronically plugged into the biochemical system of cells," said senior author Mark Reed, Harold Hodgkinson Professor of Engineering & Applied Science. "These developments have profound implications both for application of nanoscience technologies and for the speed and sensitivity they bring to the future of diagnostics."
Schematic of nanowire sensors operating in solution. Credit: Nature
An interdisciplinary team of engineers in the Yale Institute for Nanoscience and Quantum Engineering has overcome hurdles in NW synthesis by using a tried-and-true process of wet-etch lithography on commercially available silicon-on-insulator wafers. These NWs are structurally stable and demonstrate an unprecedented sensitivity as sensors for detection of antibodies and other biologically important molecules.
According to Reed, not only can the NWs detect extremely minute concentrations (as few as 1000 individual molecules in a cubic millimeter), they can do it without the hazard or inconvenience of any added fluorescent or radioactive detection probes.
The study demonstrated ability of the NWs to monitor antibody binding, and to sense real-time live cellular immune response using T-lymphocyte activation as a model. Within approximately 10 seconds, the NW could register T-cell activation as the release acid to the device. The basis for the sensors is the detection of hydrogen ions or acidity, within the physiological range of reactions in the body. Traditional assays for detection of immune system cells such as T cells or for antibodies usually take hours to complete.
"The ability to differentiate between immune system cells based on their function and with label-free reagents is key for rapid and reliable diagnostics as well as for advancing basic science," said co-author Tarek Fahmy, assistant professor of biomedical engineering. "These nanosensors can replace current technology with a solid-state device and the results promise to radically change the way we assay for these cells."
"The sensor is essentially on the size scale of the molecules it is designed to sense," said lead author Eric Stern, a graduate student whose thesis work has focused on designing and building nanoscale chemical and biological sensors. His project was funded by the Department of Defense and placed high importance on the capability of detecting multiple molecules, including pathogens.
"You can think of the process of making the nanowires as sculpting. It can either be done by working down from the rock or up from the clay — we carved down from the rock," said Fahmy. "Previous approaches used the equivalent of a hacksaw, we used a molecular chisel. We were able to make exactly what we wanted with the most traditional technology out there."
According to Stern, "We not only got the high quality smooth surface we wanted, but we were also able to make them smaller than we originally defined. Using the robust 'old fashioned' technology of lithography gives us manufacturing uniformity.
The authors say that although this study focuses on device and sensor performance, the strength of the approach lies in seamless integration with CMOS technology, and the approach "appears to have potential for extension to a fully integrated system, with wide use as sensors in molecular and cellular arrays."
"This project is a powerful demonstration of what we are trying to achieve in the Yale Institute of Nanoscience and Quantum Engineering," said Paul Fleury, Dean of Engineering and Director of the Institute. "It was a remarkable collaboration, of biomedical, electrical and mechanical engineering with chemistry and applied physics, that worked for all of us. And a dedicated graduate student with a focused idea made it happen."
Janet Rettig Emanuel | EurekAlert!
Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory
Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine