Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bacteria make bandage glow

07.11.2001


A microelectronic sensor may alert doctors to bacterial hazards.


Warning colours: bacteria make silicon wafers glow.
© University of Rochester


Silicon could leave a 100-year-old staining technique standing.
© University of Rochester



Smart bandages could soon alert doctors to the presence of certain bacteria in a wound by glowing different colours. Researchers in the United States have created a tiny device that emits faint light of two colours in response to two types of bug1.

Benjamin Miller, of the University of Rochester in New York State, and colleagues hope that a refined sensor might ultimately generate an instant and easily recognizable array of colours that signify dangerous or antibiotic-resistant strains. So far, the device produces only a very small colour change, which is not detectable with the naked eye.


Currently, the faint glow alters only in the presence of ’Gram-negative’ bacteria. Most bacteria are either ’Gram-positive’ or Gram-negative; a dye called crystal violet stains Gram-positive bacteria blue-violet and Gram-negative bacteria red. This staining procedure was discovered in 1884 by the Danish biologist Hans Christian Joachim Gram and is still used today to distinguish the two cell types.

Differences in the chemical composition of the bacteria’s cell walls cause the dye to be taken up differently. A consequence of these differences is that Gram-positive bacteria are more susceptible to antibiotics, so the test can still be useful for treating infections.

Miller’s team hope to replace the cumbersome staining procedure with a simple process that registers the difference instantly and in situ. To develop the sensor, the team collaborated with Philippe Fauchet, also at Rochester, a specialist in silicon-based light-emitting devices.

Researchers like Fauchet are primarily interested in making silicon glow, to render light-based fibre-optic telecommunication compatible with silicon-chip micorelectronics. Silicon is usually a very poor light emitter, but it can be persuaded by etching it with acid to give it a porous, sponge-like structure.

Fauchet and the team found that, when Gram-negative bacteria stick to the surface of porous silicon, the colour of the light emitted changes slightly. The researchers make the silicon attract Gram-negative, but not Gram-positive, bacteria by coating it with specially designed molecules that hook chemical groups only present on Gram-negative microbes.

The team is now searching for molecular hooks that are specific to individual families of hazardous bacteria, such as Salmonella and Listeria.

References
  1. Chan, S., Horner, S. R., Fauchet, P. M. & Miller, B. L. Identification of Gram negative bacteria using nanoscale silicon microcavities. Journal of the American Chemical Society in the press (2001).

PHILIP BALL | © Nature News Service
Further information:
http://www.nature.com/nsu/011108/011108-7.html

More articles from Health and Medicine:

nachricht When added to gene therapy, plant-based compound may enable faster, more effective treatments
18.10.2019 | Scripps Research Institute

nachricht Diabetes: A next-generation therapy soon available?
17.10.2019 | Université de Genève

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Solving the mystery of quantum light in thin layers

A very special kind of light is emitted by tungsten diselenide layers. The reason for this has been unclear. Now an explanation has been found at TU Wien (Vienna)

It is an exotic phenomenon that nobody was able to explain for years: when energy is supplied to a thin layer of the material tungsten diselenide, it begins to...

Im Focus: An ultrafast glimpse of the photochemistry of the atmosphere

Researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich have explored the initial consequences of the interaction of light with molecules on the surface of nanoscopic aerosols.

The nanocosmos is constantly in motion. All natural processes are ultimately determined by the interplay between radiation and matter. Light strikes particles...

Im Focus: Shaping nanoparticles for improved quantum information technology

Particles that are mere nanometers in size are at the forefront of scientific research today. They come in many different shapes: rods, spheres, cubes, vesicles, S-shaped worms and even donut-like rings. What makes them worthy of scientific study is that, being so tiny, they exhibit quantum mechanical properties not possible with larger objects.

Researchers at the Center for Nanoscale Materials (CNM), a U.S. Department of Energy (DOE) Office of Science User Facility located at DOE's Argonne National...

Im Focus: Novel Material for Shipbuilding

A new research project at the TH Mittelhessen focusses on the development of a novel light weight design concept for leisure boats and yachts. Professor Stephan Marzi from the THM Institute of Mechanics and Materials collaborates with Krake Catamarane, which is a shipyard located in Apolda, Thuringia.

The project is set up in an international cooperation with Professor Anders Biel from Karlstad University in Sweden and the Swedish company Lamera from...

Im Focus: Controlling superconducting regions within an exotic metal

Superconductivity has fascinated scientists for many years since it offers the potential to revolutionize current technologies. Materials only become superconductors - meaning that electrons can travel in them with no resistance - at very low temperatures. These days, this unique zero resistance superconductivity is commonly found in a number of technologies, such as magnetic resonance imaging (MRI).

Future technologies, however, will harness the total synchrony of electronic behavior in superconductors - a property called the phase. There is currently a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Symposium on Functional Materials for Electrolysis, Fuel Cells and Metal-Air Batteries

02.10.2019 | Event News

NEXUS 2020: Relationships Between Architecture and Mathematics

02.10.2019 | Event News

Optical Technologies: International Symposium „Future Optics“ in Hannover

19.09.2019 | Event News

 
Latest News

Energy Flow in the Nano Range

18.10.2019 | Power and Electrical Engineering

MR-compatible Ultrasound System for the Therapeutic Application of Ultrasound

18.10.2019 | Medical Engineering

Double layer of graphene helps to control spin currents

18.10.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>