Investigators: Conor L. Evans, Ishan Barman, Ramachandra R. Dasari

Fluorescence spectroscopy and imaging are key techniques in the repertoire of the biomedical research community. In the Laser Biomedical Research Center, the investigators leverage their expertise in precision spectroscopy, contrast agent development, and coherent spatial and temporal control of ultrafast pulses to develop cutting-edge technologies for analyte-specific investigation of biological systems, from proteins to whole organisms. This fluorescence-based technology research and development builds upon 3D light sculpting techniques and short-wave infrared (SWIR) technologies developed in the current cycle with three exciting new directions:

1. Waveguide-based Raman assays

Raman spectroscopy is a promising tool for point-of-care diagnosis, but widespread clinical application is limited by its low signal strength, as well as complex and costly instrumentation. The growing field of waveguide-based Raman spectroscopy tries to solve these challenges by working toward fully integrated Raman sensors with increased interaction areas. Working with our collaborator, Dr. Balpreet Ahluwalia of the Artic University of Norway, we are developing highly sensitive waveguide-based Raman sensor by optimizing waveguide materials and design. We have recently demonstrated resonant Raman detection of hemoglobin in a tantalum pentoxide (Ta2O5) waveguide platform. read more>>

2. Label-free plasmon-enhanced Raman spectroscopy for probing the mechanochemistry of live cells

Understanding the biophysical characteristics of a single cell is of importance in elucidating cellular diversity and heterogeneity, as well as in determining signaling pathways and networks for self-renewal and differentiation. A particularly important aspect is in uncovering the role of the local mechanical environment, cues from which are transduced into a cascade of biochemical signals ultimately leading to precise biological responses. Many of the existing experimental methods, such as micropipette aspiration and atomic force microscopy (AFM), are invasive and either too slow to scale well to probing cellular structures or suffer from poor resolution. Therefore, the crucial role of the local mechanical environment and the accompanying cell surface biochemical responses remains poorly understood, particularly at the nanoscale. To this end, LBRC is developing plasmonic nanoparticle-coated vertical nanopillar arrays to enable mechanical loading of adherent cells and to incorporate surface-enhanced Raman spectroscopy (SERS) imaging to quantify and correlate biochemical changes to the mechanical deformation. read more>>

3. Portable clinical coherent Raman imaging platform

Skin cancer is the most common malignancy in the United States, with one in every five North Americans expected to develop skin cancer during their lifetime. Melanoma, which only comprises 1% of the total skin cancer cases, is by far the most fatal, with more than 10,000 deaths expected this year. The current gold standard for the diagnosis of skin cancer is biopsy followed by histopathology, but this process is invasive, time consuming, and requires expert skills to both obtain and diagnose the sample. Optical tools provide the ability to address these limitations through "virtual biopsies" of skin using noninvasive optical imaging techniques. Over the past decade, progress in confocal reflectance imaging, multiphoton microscopy, and optical coherence tomography have driven new methods and abilities for melanoma and non-melanoma skin cancer diagnosis. read more>>