Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Novel chip-based platform could simplify measurements of single molecules: A nanopore-gated optofluidic chip combines electrical and optical measurements of single molecules onto a single platform

The nanopore-gated optofluidic chip is able to distinguish influenza viruses from nanobeads.
The nanopore-gated optofluidic chip is able to distinguish influenza viruses from nanobeads.

Abstract:
Researchers at UC Santa Cruz have developed a new approach for studying single molecules and nanoparticles by combining electrical and optical measurements on an integrated chip-based platform. In a paper published July 9 in Nano Letters, the researchers reported using the device to distinguish viruses from similarly-sized nanoparticles with 100 percent fidelity.

Novel chip-based platform could simplify measurements of single molecules: A nanopore-gated optofluidic chip combines electrical and optical measurements of single molecules onto a single platform

Santa Cruz, CA | Posted on August 14th, 2014

Combining electrical and optical measurements on a single chip provides more information than either technique alone, said corresponding author Holger Schmidt, the Kapany Professor of Optoelectronics in the Baskin School of Engineering and director of the W. M. Keck Center for Nanoscale Optofluidics at UC Santa Cruz. Graduate student Shuo Liu is first author of the paper.

The new chip builds on previous work by Schmidt's lab and his collaborators at Brigham Young University to develop optofluidic chip technology for optical analysis of single molecules as they pass through a tiny fluid-filled channel on the chip. The new device incorporates a nanopore that serves two functions: it acts as a "smart gate" to control the delivery of individual molecules or nanoparticles into the channel for optical analysis; and it allows electrical measurements as a particle passes through the nanopore.

"The nanopore delivers a single molecule into the fluidic channel, where it is then available for optical measurements. This is a useful research tool for doing single-molecule studies," Schmidt said.

Biological nanopores, a technology developed by coauthor David Deamer and others at UC Santa Cruz, can be used to analyze a DNA strand as it passes through a tiny pore embedded in a membrane. Researchers apply voltage across the membrane, which pulls the negatively charged DNA through the pore. Current fluctuations as the DNA moves through the pore provide electrical signals that can be decoded to determine the genetic sequence of the strand.

With the new device, researchers are able to gather electrical measurements on a nanoparticle as it moves through a pore in a solid membrane, and then measure the optical signals when the particle encounters a beam of light in the channel. By correlating the strength of the current decrease as a particle moves through the pore, the intensity of the optical signal, and the time of each measurement, the researchers are able to discriminate among particles with different sizes and optical properties and to determine the flow speed of particles through the channel.

The chip can also be used to differentiate particles of similar size but different composition. In one experiment, the researchers combined influenza viruses with nanobeads of a similar diameter and placed the mixture above the nanopore. The virus was labeled with a red fluorescent tag and the beads were labeled with a blue tag. The researchers correlated the electrical signal with the fluorescent wavelength and the time of each measurement. They found that the blue nanobeads traveled faster through the channel than red influenza virus, perhaps because of a difference in surface charge or mass. Besides identifying pathogens in a mixture, the researchers can also count the number of virus particles.

"This could be used as an analytical device to do reliable counts of virus particles in a sample," Schmidt said.

Currently, Schmidt's group is working on methods to add optical trapping to the device. This would allow a molecule in the channel to be held in one place, investigated, and released, with the potential to analyze hundreds of molecules in an hour. "Having this all on one chip would make single-molecule measurements much easier and more convenient," Schmidt said.

###

In addition to Liu and Schmidt, the coauthors include UCSC graduate student Joshua Parks, and Yue Zhao and Aaron Hawkins at Brigham Young University. This work was supported by the Keck Center for Nanoscale Optofluidics and grants from the National Science Foundation and National Institutes of Health.

####

For more information, please click here

Contacts:
Tim Stephens

831-459-2495

Copyright © University of California - Santa Cruz

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

Crystalline Fault Lines Provide Pathway for Solar Cell Current: New tomographic AFM imaging technique reveals that microstructural defects, generally thought to be detrimental, actually improve conductivity in cadmium telluride solar cells September 26th, 2016

Researchers at the Catalan Institute of Nanoscience and Nanotechnology show that bending semiconductors generates electricity September 26th, 2016

Chains of nanogold forged with atomic precision September 23rd, 2016

Tattoo therapy could ease chronic disease: Rice-made nanoparticles tested at Baylor College of Medicine may help control autoimmune diseases September 23rd, 2016

Microfluidics/Nanofluidics

Novel nanoscale detection of real-time DNA amplification holds promise for diagnostics: Research team led by Nagoya University develop a label-free method for detecting DNA amplification in real time based on refractive index changes in diffracted light September 12th, 2016

W.M. Keck Foundation awards Cal State LA a $375,000 research and education grant August 4th, 2016

Researchers invent 'smart' thread that collects diagnostic data when sutured into tissue: Advances could pave way for new generation of implantable and wearable diagnostics July 18th, 2016

Droplets finally all the same size -- in a nanodroplet library June 20th, 2016

Govt.-Legislation/Regulation/Funding/Policy

Crystalline Fault Lines Provide Pathway for Solar Cell Current: New tomographic AFM imaging technique reveals that microstructural defects, generally thought to be detrimental, actually improve conductivity in cadmium telluride solar cells September 26th, 2016

Tattoo therapy could ease chronic disease: Rice-made nanoparticles tested at Baylor College of Medicine may help control autoimmune diseases September 23rd, 2016

PHENOMEN is a FET-Open Research Project aiming to lay the foundations a new information technology September 19th, 2016

NIST Patents Single-Photon Detector for Potential Encryption and Sensing Apps September 16th, 2016

Discoveries

Crystalline Fault Lines Provide Pathway for Solar Cell Current: New tomographic AFM imaging technique reveals that microstructural defects, generally thought to be detrimental, actually improve conductivity in cadmium telluride solar cells September 26th, 2016

Researchers at the Catalan Institute of Nanoscience and Nanotechnology show that bending semiconductors generates electricity September 26th, 2016

Chains of nanogold forged with atomic precision September 23rd, 2016

Tattoo therapy could ease chronic disease: Rice-made nanoparticles tested at Baylor College of Medicine may help control autoimmune diseases September 23rd, 2016

Announcements

Crystalline Fault Lines Provide Pathway for Solar Cell Current: New tomographic AFM imaging technique reveals that microstructural defects, generally thought to be detrimental, actually improve conductivity in cadmium telluride solar cells September 26th, 2016

Researchers at the Catalan Institute of Nanoscience and Nanotechnology show that bending semiconductors generates electricity September 26th, 2016

Chains of nanogold forged with atomic precision September 23rd, 2016

Tattoo therapy could ease chronic disease: Rice-made nanoparticles tested at Baylor College of Medicine may help control autoimmune diseases September 23rd, 2016

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Crystalline Fault Lines Provide Pathway for Solar Cell Current: New tomographic AFM imaging technique reveals that microstructural defects, generally thought to be detrimental, actually improve conductivity in cadmium telluride solar cells September 26th, 2016

Researchers at the Catalan Institute of Nanoscience and Nanotechnology show that bending semiconductors generates electricity September 26th, 2016

Chains of nanogold forged with atomic precision September 23rd, 2016

Tattoo therapy could ease chronic disease: Rice-made nanoparticles tested at Baylor College of Medicine may help control autoimmune diseases September 23rd, 2016

Research partnerships

Crystalline Fault Lines Provide Pathway for Solar Cell Current: New tomographic AFM imaging technique reveals that microstructural defects, generally thought to be detrimental, actually improve conductivity in cadmium telluride solar cells September 26th, 2016

Tattoo therapy could ease chronic disease: Rice-made nanoparticles tested at Baylor College of Medicine may help control autoimmune diseases September 23rd, 2016

Graphene nanoribbons show promise for healing spinal injuries: Rice University scientists develop Texas-PEG to help knit severed, damaged spinal cords September 19th, 2016

NIST Patents Single-Photon Detector for Potential Encryption and Sensing Apps September 16th, 2016

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







Car Brands
Buy website traffic