Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > NRL Scientists Unravel Complex Quantum Dot-Dopamine Interactions

Intracellular pH sensing. Fluorescent micrographs collected from COS-1 cells co-injected with 550 nm emitting QD-dopamine conjugates and red FLX internal standard nanospheres in buffer at pH 6.5. The growth media was switched to pH 11.5 supplemented with the drug Nystatin and micrographs were captured at the indicated time intervals from both the QD and FLX emission channels. Merged images are shown in the bottom row and pH values extracted at each time interval are shown below.
Intracellular pH sensing. Fluorescent micrographs collected from COS-1 cells co-injected with 550 nm emitting QD-dopamine conjugates and red FLX internal standard nanospheres in buffer at pH 6.5. The growth media was switched to pH 11.5 supplemented with the drug Nystatin and micrographs were captured at the indicated time intervals from both the QD and FLX emission channels. Merged images are shown in the bottom row and pH values extracted at each time interval are shown below.

Abstract:
Scientists at the Naval Research Laboratory in conjunction with the Scripps Research Institute in La Jolla, Ca., recently reported a detailed study of the interactions of water soluble semi-conductor quantum dots (QDs) with the electro-active neuro-transmitter dopamine. These biocompatible QD-dopamine nano-assemblies may be used as the active component for sensors that are used to detect a wide variety of target analytes ranging from sugars to peroxides.

NRL Scientists Unravel Complex Quantum Dot-Dopamine Interactions

Washington, DC | Posted on October 18th, 2010

According to NRL's Dr. Michael Stewart, a member of the research team "The nature of the QD-dopamine interaction has been the subject of more than 25 recent research papers that attempted to uncover and exploit the exact nature of how the QDs interact with these small electro-active chemicals during the sensing process. Until now, it remained unclear as to whether dopamine acted as an electron acceptor or as an electron donor to quench luminescence from the QD."

"The chemical state of dopamine changes from a protonated hydroquinone in acidic media to an oxidized quinone in basic environments. A series of carefully designed experiments allowed the research team to establish that only the quinone form is capable of acting as an electron acceptor resulting in quenching of the QD emission. The rate of quinone formation and hence QD quenching is directly proportional to pH and can therefore be used to detect changes in the pH of solutions. Using this nano-scale sensor, the research team was able to demonstrate pH sensing in solution and even visualize changes inside cells as cell cultures underwent drug-induced alkalosis," explained Dr. Scott Trammell.

The interdisciplinary group of scientists involved in this project from NRL include: Dr. Michael Stewart and Dr. Kimihiro Susumu of NRL's Optical Sciences Division, and Dr. Igor Medintz, Dr. Scott Trammell, and Dr. James Delehanty from NRL's Center for Bio/Molecular Science and Engineering, along with Professor Phillip Dawson and Dr. Juan B. Blanco-Canosa of the Scripps Research Institute.

This research was supported by NRL's Nanoscience Institute and the Defense Threat Reduction Agency (DTRA), and is focused on areas tasked to the Department of Defense under the President's National Nanotechnology Initiative. The research was published in the August 2010 issue of Nature Materials.

####

For more information, please click here

Contacts:
Dom Panciarelli
(202) 767-2541

Copyright © Naval Research Laboratory

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

News and information

Pixelligent Launches New PixClear® Light Extraction Materials for OLED Lighting August 4th, 2015

The annual meeting on High Power Diode Lasers & Systems will be held as part of the Enlighten Conference, October 14th & 15th August 4th, 2015

Atomic view of microtubules: Berkeley Lab researchers achieve record 3.5 angstroms resolution and visualize action of a major microtubule-regulating protein August 4th, 2015

World's quietest gas lets physicists hear faint quantum effects August 4th, 2015

Govt.-Legislation/Regulation/Funding/Policy

Atomic view of microtubules: Berkeley Lab researchers achieve record 3.5 angstroms resolution and visualize action of a major microtubule-regulating protein August 4th, 2015

Small tilt in magnets makes them viable memory chips August 3rd, 2015

Vaccine with virus-like nanoparticles effective treatment for RSV, study finds August 3rd, 2015

MIPT researchers clear the way for fast plasmonic chips August 3rd, 2015

Sensors

Quantum states in a nano-object manipulated using a mechanical system August 3rd, 2015

Diagnosis of Salmonella Bacterium-Caused Food Poisoning by Biosensors August 3rd, 2015

Gold-diamond nanodevice for hyperlocalised cancer therapy: Gold nanorods can be used as remote controlled nanoheaters delivering the right amount of thermal treatment to cancer cells, thanks to diamond nanocrystals used as temperature sensors August 1st, 2015

Advances and Applications in Biosensing, Sensor Power, and Sensor R&D to be Covered at Sensors Global Summit August 1st, 2015

Announcements

Artificial blood vessels become resistant to thrombosis August 4th, 2015

Engineering a better 'Do: Purdue researchers are learning how August 4th, 2015

Proving nanoparticles in sunscreen products August 4th, 2015

Global Carbon Nanotubes Industry 2015: Acute Market Reports August 4th, 2015

Military

Self-assembling, biomimetic membranes may aid water filtration August 1st, 2015

Take a trip through the brain July 30th, 2015

Sol-gel capacitor dielectric offers record-high energy storage July 30th, 2015

Reshaping the solar spectrum to turn light to electricity: UC Riverside researchers find a way to use the infrared region of the sun's spectrum to make solar cells more efficient July 27th, 2015

Quantum Dots/Rods

Quantum networks: Back and forth are not equal distances! July 28th, 2015

Superfast fluorescence sets new speed record: Plasmonic device has speed and efficiency to serve optical computers July 27th, 2015

Engineered hybrid crystal opens new frontiers for high-efficiency lighting: University of Toronto researchers successfully combine 2 different materials to create new hyper-efficient light-emitting crystal July 16th, 2015

Down to the quantum dot: Jülich researchers develop ultrahigh-resolution 3-D microscopy technique for electric fields July 7th, 2015

Nanobiotechnology

Atomic view of microtubules: Berkeley Lab researchers achieve record 3.5 angstroms resolution and visualize action of a major microtubule-regulating protein August 4th, 2015

Heating and cooling with light leads to ultrafast DNA diagnostics July 31st, 2015

European Technology Platform for Nanomedicine and ENATRANS European Consortium Launch the 2nd edition of the Nanomedicine Award: The Award to be presented at BIO-Europe conference in Munich, November 2015 July 30th, 2015

New computer model could explain how simple molecules took first step toward life: Two Brookhaven researchers developed theoretical model to explain the origins of self-replicating molecules July 28th, 2015

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