Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Microprinting technique is for patterning single molecules

Abstract:
A new process for creating patterns of individual molecules on a surface combines control of self-assembled monolayers (SAMs) and a soft-lithography technique known as microcontact printing. Scientists use the process, known as "microcontact insertion printing" to build surfaces that have molecules with specific functions inserted at known intervals on a surface. The new technique, with potential applications ranging from analysis of biochemical mixtures to molecular-scale electronic components, will be described as the cover story of the Feb. 5 issue of the journal Applied Physics Letters by a team led by Penn State researchers Paul S. Weiss, distinguished professor of chemistry and physics; Mark Horn, associate professor of engineering science and mechanics; and Anne M. Andrews, assistant professor of veterinary and biomedical sciences.

Microprinting technique is for patterning single molecules

University Park, PA | Posted on February 1st, 2007

Microcontact insertion is based on the technique of microcontact printing, in which a patterned rubber-like stamp is "inked" with a solution of molecules and then applied to a surface. However, the insertion technique does not apply molecules to the entire surface contacted, but instead fills only defects -- molecule-sized gaps -- in a layer of molecules that previously has been placed on and attached to the surface. "Lithography cannot place molecules with nanometer precision," said Weiss, "but by building the defects into the surface and then filling them selectively with this process, we can place the isolated molecules in a predesigned nano-scale or micro-scale pattern."

The process of microcontact insertion printing starts with a self-assembled monolayer (SAM) -- a chemical deposition on the surface that is one molecule thick. The researchers can build the SAM with defects or regions in which the surface is not covered by the film. By controlling the type, size and number of the defects, they create a pattern in which the surface appears as a matrix of exposed dots. In one example, there is an average of 10 molecules between defects, making an average separation between inserted molecules of about 5 nanometers. If defects are made larger, then more molecules are inserted in each one.

After the formation of the matrix with controlled defects, the microcontact printing technique is used to fill the exposed parts of the surface. "We use the stamp to attach molecules to the open surface," said Weiss. "Because each molecule is surrounded by the SAM, it stays in place and there is no migration." Using a series of stamps allows different molecules to be placed on the surface in a pattern, with each region of the surface holding a different type of functional molecule tethered to the surface and held in place by the surrounding inert monolayer.

The chemical functionality of the attached molecule can be made in a way that will capture specific types of molecules from a mixture. The pattern of functionalities creates a multiplexed capture surface on which chemical compounds, such as proteins, other biological molecules or environmental contaminants can be separated from a complex mixture. Each part of the pattern can be designed for specific classes of target molecules so that a single patterned surface can be used to determine the identity and concentration of multiple components of the mixture.

In addition to its application in creation of surfaces with specific selectivity, the microcontact-insertion process could allow the controlled deposition of molecules that can interact in specific ways. This application could be used to build electronic components or other functional surfaces.

The work was a collaboration between the Weiss group, specializing in surface chemistry and self-assembly, the Andrews group, specializing in neuroscience and biosensing, and the Horn group, specializing in nanolithography. In addition to Weiss, Andrews and Horn, the Penn State research team included postdoctoral researcher Susan D. Gillmor and graduate students Thomas J. Mullen III, Charan Srinivasan, J. Nathan Hohman and Mitchell J. Shuster. The work was performed as a part of both the National Science Foundation funded Center for Nanoscale Science and Penn State's node of the National Nanotechnology Infrastructure Network.

####

For more information, please click here

Contacts:
Barbara Kennedy

www.science.psu.edu
814-863-4682

Copyright © Penn State

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

Nanoelectronics

NIST offers electronics industry 2 ways to snoop on self-organizing molecules October 22nd, 2014

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

Discoveries

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

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

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

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

Announcements

Haydale Secures Exclusive Development and Supply Agreement with Tantec A/S: New reactors to be built and commissioned by Tantec A/S represent another step forward towards the commercialisation of graphene October 24th, 2014

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

Human Interest/Art

Iran-Made Respiratory Nano Masks Provided to Hajj Pilgrims October 23rd, 2014

Japanese gold leaf artists worked on a nano-scale: Study demonstrates X-ray fluorescence spectroscopy is a non-destructive way to date artwork July 3rd, 2014

Harry Potter-style invisibility cloaks: A real possibility next Christmas? Forget socks and shaving foam, the big kids of tomorrow want an invisible cloak for Christmas December 19th, 2013

Chicago Awareness Organization First Not-for-Profit to Sponsor Dog Training to Detect Ovarian Cancer Odorants December 12th, 2013

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