Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Diatom biosensor could shine light on future nanomaterials: Discovery could lead to new methods for environmental remediation and speeding up chemical reactions

A side and overhead view of the microscopic marine diatom Thalassiosira pseudonana. PNNL scientists used this species to develop a fluorescent biosensor that changes its glow in the presence of the sugar ribose.
Photo courtesy of Nils Kroger, Universitat Regensburg.
A side and overhead view of the microscopic marine diatom Thalassiosira pseudonana. PNNL scientists used this species to develop a fluorescent biosensor that changes its glow in the presence of the sugar ribose.

Photo courtesy of Nils Kroger, Universitat Regensburg.

Abstract:
A glow coming from the glassy shell of microscopic marine algae called diatoms could someday help us detect chemicals and other substances in water samples. And the fact that this diatom can glow in response to an external substance could also help researchers develop a variety of new, diatom-inspired nanomaterials that could solve problems in sensing, catalysis and environmental remediation.

Diatom biosensor could shine light on future nanomaterials: Discovery could lead to new methods for environmental remediation and speeding up chemical reactions

Sequim, WA | Posted on March 22nd, 2012

Fluorescence is the key characteristic of a new biosensor developed by researchers at the Department of Energy's Pacific Northwest National Laboratory. The biosensor, described in a paper published this week in the scientific journal PLoS ONE, includes fluorescent proteins embedded in a diatom shell that alter their glow when they are exposed to a particular substance.

"Like tiny glass sculptures, the diverse silica shells of diatoms have long intrigued scientists," said lead author and molecular biologist Kate Marshall, who works out of PNNL's Marine Sciences Laboratory in Sequim, Wash. "And the way our biosensor works could make diatoms even more attractive to scientists because it could pave the way for the development of novel, synthetic silica materials."

Diatoms are perhaps best known as the tiny algae that make up the bulk of phytoplankton, the plant base of the marine food chain that feeds the ocean's creatures. But materials scientists are fascinated by diatoms for another reason: the intricate, highly-ordered patterns that make up their microscopic shells, which are mostly made of silica. Researchers are looking at these minuscule glass cages to solve problems in a number of areas, including sensing, catalysis and environmental remediation.

PNNL Laboratory Fellow and corresponding author Guri Roesijadi found inspiration for this biosensor in previous work by other researchers, who showed it's possible to insert proteins in diatom shells through genetic engineering. Using that work as a starting point, Roesijadi, Marshall and their PNNL colleagues aimed to use fluorescent proteins to turn diatoms into a biosensor. They specifically aimed to create a reagent-less biosensor, meaning one that detects a target substance on its own and without depending on another chemical or substance.

Well-equipped diatom

As a test case, the PNNL team inserted genes for their biosensor into Thalassiosira pseudonana, a well-studied marine diatom whose shell resembles a hatbox. The new genes allowed the diatoms to produce a protein that is the biosensor.

At the heart of the biosensor is the ribose-binding protein, which, as the name suggests, attaches to the sugar ribose. Each ribose-binding protein is then flanked by two other proteins — one that glows blue and another that glows yellow. This three-protein complex attaches to the silica shell while the diatom grows.

In the absence of ribose, the two fluorescent proteins sit close to one another. They're close enough that the energy in the blue protein's fluorescence is easily handed off, or transferred, to the neighboring yellow protein. This process, called fluorescence resonance energy transfer, or FRET, is akin to the blue protein shining a flashlight at the yellow protein, which then glows yellow.

But when ribose binds to the diatom, the ribose-binding protein changes its shape. This moves the blue and yellow fluorescent proteins apart in the process, and the amount of light energy that the blue protein shines on the yellow protein declines. This causes the biosensor to display more blue light.

Microscopic light show

Regardless of whether or not ribose is bound to the diatom's biosensor, the biosensor always emits some blue or yellow glow when it's exposed to energy under a microscope. But the key difference is how much of each kind of light is displayed.

The PNNL team distinguished between light from the two proteins with a fluorescence microscope that was equipped with a photon sensor. The sensor allowed them to measure the intensities of the unique wavelengths of light given off by each of the fluorescent proteins. By calculating the ratio of the two wavelengths, they could determine if the diatom biosensor was exposed to ribose, and how much of ribose was present.

The team also succeeded in making the biosensor work with the shell alone, after it was removed from the living diatom. Removing the living diatom provides researchers greater flexibility in how and where the silica biosensor can be used. The Office of Naval Research, which funded the research, believes biosensors based on modifying a diatom's silica shell may prove useful for detecting threats such as explosives in the marine environment.

"With this research, we've made our important first steps to show it's possible to genetically engineer organisms such as diatoms to create advanced materials for numerous applications," Marshall said.

Co-authors on the paper include scientists at EMSL, DOE's Environmental Molecular Sciences Laboratory at PNNL's Richland, Wash., campus. They used EMSL's mass spectrometry capabilities to verify the team had the correct ribose-binding and fluorescent proteins before adding them to the diatoms.

####

About Pacific Northwest National Laborator
Interdisciplinary teams at Pacific Northwest National Laboratory address many of America's most pressing issues in energy, the environment and national security through advances in basic and applied science. PNNL employs 4,700 staff, has an annual budget of nearly $1.1 billion, and has been managed for the U.S. Department of Energy by Ohio-based Battelle since the laboratory's inception in 1965.

EMSL, the Environmental Molecular Sciences Laboratory, is a national scientific user facility sponsored by the Department of Energy's Office of Science. Located at Pacific Northwest National Laboratory in Richland, Wash., EMSL offers an open, collaborative environment for scientific discovery to researchers around the world. Its integrated computational and experimental resources enable researchers to realize important scientific insights and create new technologies.

For more information, please click here

Contacts:
Franny White
PNNL
(509) 375-6904

Copyright © Pacific Northwest National Laborator

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 Links

REFERENCE: Kathryn E. Marshall, Errol W. Robinson, Shawna M. Hengel, Liljana Pasa-Tolic, Guritno Roesijadi, "FRET Imaging of Diatoms Expressing a Biosilica-Localized Ribose Sensor," PLoS ONE, March 21, 2012, DOI: 10.1371/journal.pone.0033771:

Related News Press

News and information

QuantumWise guides the semiconductor industry towards the atomic scale October 24th, 2014

Nanoparticle technology triples the production of biogas October 23rd, 2014

SUNY Polytechnic Institute Invites the Public to Attend its Popular Statewide 'NANOvember' Series of Outreach and Educational Events October 23rd, 2014

Chemistry

Iranian, Malaysian Scientists Study Nanophotocatalysts for Water Purification October 23rd, 2014

Laboratories

National Synchrotron Light Source II Achieves 'First Light' October 23rd, 2014

Novel Rocket Design Flight Tested: New Rocket Propellant and Motor Design Offers High Performance and Safety October 23rd, 2014

Govt.-Legislation/Regulation/Funding/Policy

Novel Rocket Design Flight Tested: New Rocket Propellant and Motor Design Offers High Performance and Safety October 23rd, 2014

Strengthening thin-film bonds with ultrafast data collection October 23rd, 2014

Brookhaven Lab Launches Computational Science Initiative:Leveraging computational science expertise and investments across the Laboratory to tackle "big data" challenges October 22nd, 2014

Bipolar Disorder Discovery at the Nano Level: Tiny structures found in brain synapses help scientists better understand disorder October 22nd, 2014

Sensors

MEMS & Sensors Technology Showcase: Finalists Announced for MEMS Executive Congress US 2014 October 23rd, 2014

Journal Nanotechnology Progress International (JONPI), 2014, Volume 5, Issue 1, pp 1-24 October 22nd, 2014

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Graphenea opens US branch October 16th, 2014

Discoveries

QuantumWise guides the semiconductor industry towards the atomic scale October 24th, 2014

Iranian Scientists Apply Nanotechnology to Produce Surgery Suture October 23rd, 2014

Iranian, Malaysian Scientists Study Nanophotocatalysts for Water Purification October 23rd, 2014

Nanoparticle technology triples the production of biogas October 23rd, 2014

Materials/Metamaterials

Researchers patent a nanofluid that improves heat conductivity October 22nd, 2014

Materials for the next generation of electronics and photovoltaics: MacArthur Fellow develops new uses for carbon nanotubes October 21st, 2014

Super stable garnet ceramics may be ideal for high-energy lithium batteries October 21st, 2014

Could I squeeze by you? Ames Laboratory scientists model molecular movement within narrow channels of mesoporous nanoparticles October 21st, 2014

Announcements

QuantumWise guides the semiconductor industry towards the atomic scale October 24th, 2014

SUNY Polytechnic Institute Invites the Public to Attend its Popular Statewide 'NANOvember' Series of Outreach and Educational Events October 23rd, 2014

Advancing thin film research with nanostructured AZO: Innovnano’s unique and cost-effective AZO sputtering targets for the production of transparent conducting oxides October 23rd, 2014

Strengthening thin-film bonds with ultrafast data collection October 23rd, 2014

Military

NanoTechnology for Defense (NT4D) October 22nd, 2014

Crystallizing the DNA nanotechnology dream: Scientists have designed the first large DNA crystals with precisely prescribed depths and complex 3D features, which could create revolutionary nanodevices October 20th, 2014

Imaging electric charge propagating along microbial nanowires October 20th, 2014

1980s aircraft helps quantum technology take flight October 20th, 2014

Environment

Iranian, Malaysian Scientists Study Nanophotocatalysts for Water Purification October 23rd, 2014

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Physicists build reversible laser tractor beam October 20th, 2014

Plastic nanoparticles also harm freshwater organisms October 18th, 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