Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button


Home > Press > Microprinting technique is for patterning single molecules

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

Barbara Kennedy

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.

Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press


First circularly polarized light detector on a silicon chip: Promises to expand use of polarized light for drug screening, surveillance, optical communications September 24th, 2015

Nanoelectronics could get a boost from carbon research: The smallest of electronics could one day have the ability to turn on and off on an atomic scale September 17th, 2015

Nanotech expertise earns Virginia Tech a spot in National Science Foundation network: New center's focus will be on earth, environmental nanotechnology September 16th, 2015

UT researchers give nanosheets local magnetic properties September 11th, 2015


Modification of Nanofiltration Membranes in Water Purification Process October 7th, 2015

Fractals aid efforts to understand heat transport at nanoscale October 6th, 2015

Electron tomography with 3,487 images in 3.5 seconds: High-speed electron tomography sets new standards for 3-D images of the nanoworld October 6th, 2015

Molecular nanoribbons as electronic highways October 6th, 2015


Modification of Nanofiltration Membranes in Water Purification Process October 7th, 2015

Superconductivity trained to promote magnetization: Russian scientist and her colleagues discovered the superconductivity effect, which will help to create future supercomputers October 6th, 2015

Nanoscale photodetector shows promise to improve the capacity of photonic circuits: Researchers at the University of Rochester have fabricated a device in which light can induce a current using a silver nanowire -- an important step toward harnessing light to speed up the next ge October 6th, 2015

Big range of behaviors for tiny graphene pores: Like biological channels, graphene pores are selective for certain types of ions October 6th, 2015

Human Interest/Art

Bionic liver micro-organs explain off-target toxicity of acetaminophen (Tylenol): Israeli-German partnership aims to replace animal experiments with advanced liver-on-chip devices August 17th, 2015

Omni Nano and Time Warner Cable Partner to Provide Nanotechnology Education to the Boys & Girls Clubs of Los Angeles: A $10,000 Donation to Benefit Youth of Los Angeles County's Boys & Girls Clubs August 4th, 2015

Kalam: versatility personified August 1st, 2015

Pakistani Students Who Survived Terror Attack to Attend Weeklong “NanoDiscovery Institute” at SUNY Poly CNSE in Albany July 29th, 2015

The latest news from around the world, FREE

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

Nanotechnology Now Featured Books


The Hunger Project

Car Brands
Buy website traffic