0805233 Halterman

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Selective Tethering to Gold Surfaces Ronald L. Halterman, University of Oklahoma Norman Campus, DMR 0805233 One key to preparing next generation optoelectrical devices is coupling the properties of tunable organic dyes with the electronic (plasmonic) properties of gold nanoparticles. Our efforts have focused on the the selective and controlled attachment of organic groups to the surface of gold. A significant hurdle was encountered when trying to add dye-functionalized molecules to the gold surface when we observed that the adsorbing molecules clumped and did not form controlled, uniform coating of the surface. We have moved to an indirect placement of the desired groups on the surface by first adding a “pre-functionalized” molecule in a controlled manner to the surface and then going back in a second step to attach the desired functional group to the Functionalized thiols can be handled more readily as the protected thioacetate. Molecularly-ordered coating of gold surface is consistently possible using an in situ activation of the thioacetates by organic bases. Bumm and Halterman, et al Langmuir, 2010, 26 (16), pp 13221–13226

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Selective Tethering to Gold Surfaces Ronald L. Halterman, University of Oklahoma Norman Campus, DMR 0805233. - PowerPoint PPT Presentation

Transcript of 0805233 Halterman

Page 1: 0805233 Halterman

Selective Tethering to Gold SurfacesRonald L. Halterman, University of Oklahoma Norman Campus, DMR 0805233

One key to preparing next generation optoelectrical devices is coupling the properties of tunable organic dyes with the electronic (plasmonic) properties of gold nanoparticles. Our efforts have focused on the the selective and controlled attachment of organic groups to the surface of gold.

A significant hurdle was encountered when trying to add dye-functionalized molecules to the gold surface when we observed that the adsorbing molecules clumped and did not form controlled, uniform coating of the surface. We have moved to an indirect placement of the desired groups on the surface by first adding a “pre-functionalized” molecule in a controlled manner to the surface and then going back in a second step to attach the desired functional group to the head group on the initial adsorbate.

Shown here is an molecularly resolved image demonstrating that we can convert a more easily handled form of the adsorbate into a reactive form in such a way that we get highly controlled coating of the gold surface.

Functionalized thiols can be handled more readily as the protected thioacetate. Molecularly-ordered coating of gold surface is consistently possible using an in situ activation of the thioacetates by organic bases. Bumm and Halterman, et al Langmuir, 2010, 26 (16), pp 13221–13226

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Helping Students to “See” Molecules Ronald L. Halterman, University of Oklahoma Norman Campus, DMR 0805233

One of the key features of our research is the use of scanning tunneling microscopy to image samples at a molecular resolution. This powerful technique to examine the structure of molecules at the smallest chemical scale has broad applications and is a cornerstone of the OU NanoLab undergraduate physics course. Participants in the DMR funded research project provide needed valuable expertise in the training of this wider pool of students.

Results of this DMR research project have been presented at conferences by participating faculty, graduate students and undergraduates, including the 2010 Oklahoma Pentasectional Meeting of the American Chemical Society that was organized by co-PI and ACS section chair L. Bumm (OU Dept of Physics/Astronomy).

The scanning tunneling microscopy provides resolution high enough to image individual molecules on a surface.