Spectroscopy Techniques for
Dr. Denis Boudreau’s research activities at Université Laval and the Center for Optics, Photonics and Lasers (COPL) in Québec lie at the interface between luminescent and plasmonic nanomaterial synthesis, molecular electronic/vibrational spectroscopy, and optical sensor design for biological, environmental, and industrial sensing applications.
His graduate students make daily use of steady-state and time-resolved fluorescence and plasmon-enhanced fluorescence spectrometry, Raman and surface-enhanced Raman spectroscopy, and darkfield/epifluorescence imaging.
“One of the ways we use FERGIE is together with a custom-made confocal microscope to collect single-particle fluorescence and scattering data that is then correlated with electron microscopy data.”
— Dr. Denis Boudreau
The group’s FERGIE-facilitated research projects include (1) synthesis and characterization of plasmonic nanoparticles for biosensor design, (2) optical waveguide-based optical probes for in vitro and in vivo biological sensing, and (3) surface-enhanced Raman spectrometry of metabolic biomarkers.
FERGIE in Action (Project 1)
Synthesis and Characterization of Plasmonic Nanoparticles for Biosensor Design
Dr. Boudreau’s research group specializes in the synthesis of luminescent nanoparticles consisting of a plasmonic core coated with concentric dielectric layers doped with fluorophores sensitive to various physical or chemical stimuli. Since the size and shape of the core has a dramatic impact on luminescent behavior, the researchers use single-particle spectroscopy to establish design rules that will lead to nanostructures with optimal properties.
In concert with a custom-made confocal microscope, FERGIE is utilized to collect single-particle fluorescence and scattering data, which is then correlated with electron microscopy data. “The ease with which FERGIE can be coupled to an optical setup, either free-space or via optical fiber, makes this very easy,” notes Dr. Boudreau.
FERGIE in Action (Project 2)
Optical Waveguide-Based Optical Probes for In Vitro and In Vivo Biological Sensing
Species-selective nanoparticles are attached onto microscope slides and brought in contact with cell cultures to image the evolution of key cell metabolites. The same plasmonic nanomaterials are also being grafted on the tip of custom-made optical fibers for remote chemical or biological sensing. Current applications include process monitoring in water treatment plants and in vivo molecular sensing in model animals.
“In time, this fiber sensor will integrate multichannel architectures and fluorescent sensing structures responsive to various microbial metabolites, making it a flexible tool for sensing the intestinal microbiome with unprecedented resolution,” explains graduate student Victor Azzi.
“We can switch FERGIE from the microscope to a microfluidic flow chamber to the connectorized fiber sensor in mere minutes. It’s a fantastic tool.”
— Victor Azzi
FERGIE in Action (Project 3)
Surface-Enhanced Raman Spectrometry of Metabolic Biomarkers
Dr. Boudreau’s group is collaborating with other research groups on the development of methodologies based on plasmonic nanomaterials and surface-enhanced Raman spectrometry (SERS) for in situ identification and quantification of cell metabolic markers. Applications include studying the acclimation of phytoplankton to changes in global climate (with Dr. C. Lovejoy, U. Laval, and J.F. Masson, U. Montreal) as well as in vivo monitoring of cholic acid derivatives in the gut microbiota (O. Barbier, A. Marette, and R. Vallée, U. Laval).
In the lab.
Dr. Denis Boudreau
Professor of Analytical Chemistry
Center for Optics, Photonics and Lasers (COPL)