Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Gilded Bacteria

Abstract:
Humidity sensor: hybrid nanoelectronics made from living bacteria and gold nanoparticles

Gilded Bacteria

October 07, 2005

Living organisms as an integral part of electronic components? What may look like science fiction at first glance is actually a serious approach to the nanoelectronics of tomorrow. Living organisms could provide the required nanostructures. Researchers at the University of Nebraska (Lincoln, USA) have now shown that bacteria coated with gold nanoparticles can function as a humidity sensor.

The properties of metallic nanoparticles differ radically from those of larger particles and are of great interest for nanoelectronics. In order to use nanoparticles, they must be placed on a suitable support, a “nanoscaffold.” “Biological structures have proven to be promising supports,” explains Ravi Saraf, “especially when their responses to stimuli can be integrated.”

Saraf and his co-worker, Vikas Berry, produced a chip covered with extremely fine gold electrodes and applied a suspension of Bacillus cereus. On such surfaces, these long bacteria basically lie down to form bridges between the pairs of electrodes. Then the nanoparticles come in: the researchers dipped their chip into a solution of gold nanoparticles coated with polylysine, a synthetic protein. The tiny gold particles are strongly attracted to the bacterial surface, which contains long, brushlike, highly mobile chain molecules that are negatively charged. Like tentacles, these surround the gold particles - positively charged by the polylysine - and hold them tight. At the end of this process, the bacteria are coated with a thin layer of gold nanoparticles - and are still alive.

The researchers apply a voltage of 10 V across the electrode pairs and measure the current across the bacterial bridges to complete the bioelectronic humidity sensor. If the humidity is increased from about 0 to 20%, the current decerases by a factor of 40. Why does this chip react so sensitively to changes in humidity? Moisture causes the bacterial membrane to swell, which increases the distance between the individual gold particles attached to it by about 0.2 nm. This is not much, but it is enough to hinder electron transport between the particles. Unlike a “normal” macroscopic gold layer, in which the electrons can “flow” unhindered, here they must “jump” from one particle to the next.

“Our humidity sensor demonstrates the vast potential that lies in hybrid structures containing microorganisms and nanoparticles,” says Saraf.

####


Author: Ravi F. Saraf, University of Nebraska, Lincoln (USA), link

Title: Self-Assembly of Nanoparticles on Live Bacterium: An Avenue to Fabricate Electronic Devices

Angewandte Chemie International Edition 2005, 44, 6668, doi: 10.1002/anie.200501711

Contact:
Editorial office: angewandte@wiley-vch.de

David Greenberg (US)
dgreenbe@wiley.com

Julia Lampam (UK)
jlampam@wiley.co.uk

Copyright © Angewandte Chemie

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Possible Futures

IBM Announces $3 Billion Research Initiative to Tackle Chip Grand Challenges for Cloud and Big Data Systems: Scientists and engineers to push limits of silicon technology to 7 nanometers and below and create post-silicon future July 10th, 2014

Virus structure inspires novel understanding of onion-like carbon nanoparticles April 10th, 2014

Local girl does good March 22nd, 2014

Surface Characteristics Influence Cellular Growth on Semiconductor Material March 12th, 2014

Sensors

Production of Toxic Gas Sensor Based on Nanorods July 28th, 2014

Compact Vibration Harvester Power Supply with Highest Efficiency Opens Door to “Fix-and-Forget” Sensor Nodes July 23rd, 2014

Nano-sized Chip "Sniffs Out" Explosives Far Better than Trained Dogs: TAU researcher's groundbreaking sensor detects miniscule concentrations of hazardous materials in the air July 23rd, 2014

Tiny laser sensor heightens bomb detection sensitivity July 19th, 2014

Nanoelectronics

A*STAR and industry form S$200M semiconductor R&D July 25th, 2014

A Crystal Wedding in the Nanocosmos July 23rd, 2014

3-D nanostructure could benefit nanoelectronics, gas storage: Rice U. researchers predict functional advantages of 3-D boron nitride July 15th, 2014

IBM Announces $3 Billion Research Initiative to Tackle Chip Grand Challenges for Cloud and Big Data Systems: Scientists and engineers to push limits of silicon technology to 7 nanometers and below and create post-silicon future July 10th, 2014

Materials/Metamaterials

Seeing is bead-lieving: Rice University scientists create model 'bead-spring' chains with tunable properties July 28th, 2014

Silicene Labs Announces the Launch of 2D Materials Briefing Book™ and 2D Materials Road-Heat Map™: Contributors Include One of the World's Foremost 2D Materials Scientists July 25th, 2014

Silicene Labs Announces the Launch of Patent-Pending, 2D Materials Composite Index™ : The Initial 2D Materials Composite Index™ for Q2 2014 Is: 857.3; Founders Include World-Renowned Physicist and Seasoned Business and IP Professionals July 24th, 2014

Iranian Scientists Produce Transparent Nanocomposite Coatings with Longer Lifetime July 24th, 2014

Announcements

Measuring the Smallest Magnets July 28th, 2014

WITec to host the 11th Confocal Raman Imaging Symposium from September 29th - October 1st in Ulm, Germany July 28th, 2014

FEI adds Phase Plate Technology and Titan Halo TEM to its Structural Biology Product Portfolio: New solutions provide the high-quality imaging and contrast necessary to analyze the 3D structure of molecules and molecular complexes July 28th, 2014

Production of Toxic Gas Sensor Based on Nanorods July 28th, 2014

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE