Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ultra-Sensitive Electrical Biosensor Unlocks Potential for Instant Diagnostic Devices

17.04.2012
Researchers at UC Santa Barbara propose Tunnel-FET based biosensor 10,000 times more sensitive than conventional FET-based sensors

A new quantum mechanical-based biosensor designed by a team at University of California, Santa Barbara offers tremendous potential for detecting biomolecules at ultra-low concentrations, from instant point-of-care disease diagnostics, to detection of trace substances for forensics and security.


Schematic of a Tunnel-FET biosensor proposed by UCSB researchers and its band diagram illustrating band-to-band-tunneling triggered by biomolecule conjugation. Credit: Peter Allen, UCSB

Kaustav Banerjee, director of the Nanoelectronics Research Lab and professor of Electrical and Computer Engineering at UCSB, and PhD student Deblina Sarkar have proposed a methodology for beating the fundamental limits of a conventional Field-Effect-Transistor (FET) by designing a Tunnel-FET (T-FET) sensor that is faster and four orders of magnitude more sensitive. The details of their study appeared in the April 2, 2012 issue of the journal Applied Physics Letters.

“This study establishes the foundation for a new generation of ultra-sensitive biosensors that expand opportunities for detection of biomolecules at extremely low concentrations,” said Samir Mitragotri, professor of Chemical Engineering and director of the Center for Bioengineering at UCSB. “Detection and diagnostics are a key area of bioengineering research at UCSB and this study represents an excellent example of UCSB's multi-faceted competencies in this exciting field.”

Biosensors based on conventional FETs have been gaining momentum as a viable technology for the medical, forensic, and security industries since they are cost-effective compared to optical detection procedures. Such biosensors allow for scalability and label-free detection of biomolecules – removing the step and expense of labeling target molecules with fluorescent dye.

The principle behind any FET-based biosensor is similar to the FETs used in digital circuit applications, except that the physical gate is removed and the work of the gate is carried out by charged versions of the biomolecules it intends to detect. For immobilizing these biomolecules, the dielectric surface enclosing the semiconductor is coated with specific receptors, which can bind to the target biomolecules – a process called conjugation.

“The thermionic emission current injection mechanism of conventional FET based biosensors puts fundamental limitations on their maximum sensitivity and minimum detection time,” said Banerjee, who conceived the idea in 2009 while studying the design of tunnel-FETs for ultra energy-efficient integrated electronics.

"We overcome these fundamental limitations by making Quantum Physics join hands with Biology" explained Sarkar, the lead author of the paper. "The key concept behind our device is a current injection mechanism that leverages biomolecule conjugation to bend the energy bands in the channel region, leading to the quantum-mechanical phenomenon of band-to-band tunneling. The result is an abrupt increase in current which is instrumental in increasing the sensitivity and reducing the response time of the proposed sensor.”

“The abruptness of current increase in an electrical switch is quantified by a parameter called subthreshold swing and the sensitivity of any FET based biosensor increases exponentially as the subthreshold swing decreases. Thus, similar devices such as Impact-ionization- or Nano-electromechanical-FETs are promising for biosensing applications,” explained Banerjee. “But since theT-FETs can be easily integrated in the widely available silicon-based semiconductor technology, they can be mass produced in a cost effective manner.”

According to the researchers, their T-FET biosensor is expected to have tremendous impact on research in genomics and proteomics, as well as pharmaceutical, clinical and forensic applications – including the growing market of in-vitro and in-vivo diagnostics. Banerjee and Sarkar have filed a patent disclosure for their technology, which the researchers anticipate can be ready for the marketplace in as few as two years.

The Nanoelectronics Research Lab (NRL) is affiliated with the UCSB College of Engineering. Professor Kaustav Banerjee is the director of the NRL and also affiliated with the California NanoSystems Institute and the Institute for Energy Efficiency at UCSB. Banerjee is a Fellow of IEEE and has been recently honored with the Humboldt Foundation’s Bessel Research Award. Deblina Sarkar is a PhD candidate in the Electrical and Computer Engineering department and one of three students worldwide to receive an IEEE Electron Devices Society PhD Fellowship in 2011.

Paper source: Applied Physics Letters

Media Contact
Melissa Van De Werfhorst
melissa@engineering.ucsb.edu

Melissa Van De Werfhorst | EurekAlert!
Further information:
http://www.ucsb.edu

More articles from Physics and Astronomy:

nachricht Further Improvement of Qubit Lifetime for Quantum Computers
09.12.2016 | Forschungszentrum Jülich

nachricht Electron highway inside crystal
09.12.2016 | Julius-Maximilians-Universität Würzburg

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron highway inside crystal

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...

Im Focus: Significantly more productivity in USP lasers

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:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

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...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

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...

Im Focus: Quantum Particles Form Droplets

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>