Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Biosensors: Sweet and simple

15.04.2011
New substrates boost the sensitivity of surface-enhanced Raman spectroscopy for the detection of glucose at physiological concentrations

Surface-enhanced Raman spectroscopy (SERS) is a highly sensitive and versatile analytical tool that is widely used in biosensing applications. In conventional Raman spectroscopy, molecules are detected by their characteristic scattering of laser light, but the sensitivity of the standard method is relatively low.

By detecting the same Raman scattering from molecules adsorbed to rough metal surfaces, however, the sensitivity can be enhanced remarkably, even allowing the detection of single molecules (see image). Unfortunately, the mechanism of this enhancement is not well understood and is strongly dependent on the combination of surface and molecular target.

Malini Olivo and co-workers at the A*STAR Singapore Bioimaging Consortium and Institute of Microelectronics have now developed a new class of surface that provides a much-needed sensitivity enhancement for the detection of glucose[1]. The new substrate promises the fast, direct and accurate detection of glucose in solution at physiological concentrations.

Olivo and her co-workers have been investigating SERS for the measurement of glucose in biological samples. Glucose has very low Raman scattering efficiency and existing substrates for SERS fail to bring the method’s sensitivity of detection up to a level suitable for detecting the typical concentrations in real samples.

Instead of the commonly used rough metal substrates, the researchers turned to silicon, which they etched to form a well-defined pattern of nanogaps. They then coated the patterned silicon with thin layers of silver and gold. In tests comparing the new substrate with commercial substrates for glucose detection, Olivo and her team found that the silicon-based substrate gave the sensitivity boost they were looking for, which they attribute to the uniformity of roughness provided by the nanogap pattern.

“We were actually very surprised by our substrate’s high reproducibility,” say Olivo. “The best reproducibility reported previously for glucose was only about 10%. However, due to the special design and pattern of our substrate, we achieved reproducibility of about 3–4%, which is outstanding.” The nanogap substrate also provided good sensitivity for the detection of glucose in the physiologically important 0–25 millimolar range.

Olivo and her co-workers are already building on their success with work on an analogous system for sensing proteins. “We would like to translate similar SERS substrate platforms to optical fibers in order to develop a minimally invasive in vivo SERS platform for clinical diagnostics,” she says. The researchers have high hopes that small sensors based on this SERS platform may one day be implanted into patients for real-time glucose sensing.

The A*STAR-affiliated researchers contributing to this research are from the Singapore Bioimaging Consortium and the Institute of Microelectronics

Journal information

[1] Dinish, U. S., Yaw, F. C., Agarwal, A. & Olivo, M. Development of highly reproducible nanogap SERS substrates: Comparative performance analysis and its application for glucose sensing. Biosensors and Bioelectronics 26, 1987–1992 (2011).

Lee Swee Heng | Research asia research news
Further information:
http://www.research.a-star.edu.sg/research/6304
http://www.researchsea.com

More articles from Life Sciences:

nachricht The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie

nachricht How protein islands form
15.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

Im Focus: Scientists improve forecast of increasing hazard on Ecuadorian volcano

Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, the Italian Space Agency (ASI), and the Instituto Geofisico--Escuela Politecnica Nacional (IGEPN) of Ecuador, showed an increasing volcanic danger on Cotopaxi in Ecuador using a powerful technique known as Interferometric Synthetic Aperture Radar (InSAR).

The Andes region in which Cotopaxi volcano is located is known to contain some of the world's most serious volcanic hazard. A mid- to large-size eruption has...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

New thruster design increases efficiency for future spaceflight

16.08.2017 | Physics and Astronomy

Transporting spin: A graphene and boron nitride heterostructure creates large spin signals

16.08.2017 | Materials Sciences

A new method for the 3-D printing of living tissues

16.08.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>