Keyword Suggestions

Account Login

Library Navigation


Browse Meetings

L1.09 - Engineered Infrared Plasmonic Metamaterials for Molecular Vibration Enhancement and Suppression Observed by Photothermal Spectral-Microscopy 
December 1, 2014   11:30am - 11:45am

Recently, the interaction between plasmonic metamaterials and vibrational modes of a molecule has been studied as a potential method for ultrasensitive light-matter interaction. It has been shown that coupling of radiative modes of plasmonic metamaterials can mimic electromagnetically induced transparency behavior as observed in atomic and molecular interference effects. In this work, we demonstrate coupling between a narrow molecular vibrational mode with a broad plasmonic resonance that enhances or suppresses the molecular resonance. At critical coupling it cancels out the absorption band entirely. The observed phenomenon is investigated by direct absorption using the FTIR and photothermal spectral-microscopy. Plasmonic metamaterials were fabricated using a liftoff process and e-beam lithography. A thin layer of liquid crystal was placed on top of the structures with a weak combinational band at 1912cm-1. By tuning the length and the periodicity of the plasmonic nano-antennae array we were able to suppress, enhance and cancel out the molecular vibrational mode. A home-built mid-IR photothermal setup is used in combination with a tunable QCL, a plasmonic substrate, an inexpensive silicon photodetector and lock-in detection to measure the sensitivity and specificity of performing vibrational infrared spectroscopy on biomolecules. Mid-IR photothermal spectroscopy combined with plasmonic metamaterials has the potential to detect ultralow concentration of absorbers using low-cost photodetectors and bright tunable QCLs.

Average Rating: (No Ratings)
  Was great, surpassed expectations, and I would recommend this
  Was good, met expectations, and I would recommend this
  Was okay, met most expectations
  Was okay but did not meet expectations
  Was bad and I would not recommend this

Performance Enhancement of Pentacene Based Organic Field-Effect Transistor through DNA Interlayer
Semiconducting Polymer-Dipeptide Nanostructures by Ultrasonically-Assisted Self-Assembling
DNA as a Molecular Wire: Distance and Sequence Dependence
Structure-Property Relationship in Biologically-Derived Eumelanin Cathodes Electrochemical Energy Storage
Artificial Physical and Chemical Awareness (proprioception) from Polymeric Motors