Extending Usable Lifetime of Plasmonic Silver Structures Designed for High Resolution Chemical Imaging and for Chemical and Biological Sensing
Abstract
The overall objective was to identify, from among different classes of coating schemes, the most fruitful approach for extending the lifetime of silver plasmonic structures used in high resolution optical spectroscopies for materials characterization or high sensitivity detection schemes. This enhanced durability will aid in Army efforts to develop high sensitivity, high selectivity schemes based on tip enhanced Raman spectroscopy (TERS) for chemical imaging and surface enhanced Raman spectroscopy (SERS) techniques for detection of explosives, chemicals, or biological agents. Protected plasmonic structures have been successfully prepared by sequential physical vapor depositions of silver and of SiOx or Al2O3 layers at very low pressures. Our key result to date is the creation of a corrosion-protected, highly enhancing plasmonic structure on an SPM tip for the first time. For the protected metallized tip the enhancement factor is of the order of 104. The vital advance made here, through materials design, is fabricating long-lasting metallized probes without compromising signal enhancement. This advance has been proven by measurements on thin films of a conductive polymer blend (PEDOT/PSS) and an inorganic material (CdS).
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2008
- Accession Number
- ADA500766
Entities
People
- Carlos Barrios
- Mark D Foster
Organizations
- University of Akron