| AVS 65th International Symposium & Exhibition | |
| Nanometer-scale Science and Technology Division | Wednesday Sessions |
| Session NS+MN+PC+SS-WeA |
| Session: | IoT Session: Bio at the Nanoscale |
| Presenter: | Scott Lea, Pacific Northwest National Laboratory |
| Authors: | A. Bhattarai, Pacific Northwest National Laboratory B.T. O'Callahan, Pacific Northwest National Laboratory P.Z. El Khoury, Pacific Northwest National Laboratory A.S. Lea, Pacific Northwest National Laboratory K.-D. Park, University of Colorado Boulder E.A. Muller, University of Colorado Boulder M.B. Raschke, University of Colorado Boulder |
| Correspondent: | Click to Email |
Existing genomic and biochemical methods cannot directly probe the physical connections involved in microbial metabolic processes over relevant length scales, spanning the nano-meso-micrometer spatial regimes. Determining the location and function of such biomolecules would aid in identifying the mechanisms governing microbial interactions. We are addressing these technical and conceptual gaps by developing a single multimodal chemical imaging platform that can interrogate biomolecules in living systems using three complementary label-free, nanoscale, ultrasensitive chemical imaging techniques:
Infrared scattering scanning near-field optical microscopy (IR s-SNOM)
Tip-enhanced Raman nano-spectroscopy (TERS)
Multimodal hyperspectral optical nano-spectroscopy.
We have built and developed these imaging modalities independently prior to integration into a single, multimodal chemical nanoscope. As part of our benchmarking experiments, we performed TERS measurements targeting prototypical systems and constructs and demonstrated <1 nanometer precision in ambient TERS chemical imaging measurements.[1] We also established an overall broader scope of TERS[2] and illustrated that TERS is not restricted to nanoscale chemical imaging, but can also be used to probe different aspects of local fields confined to a few nanometers. Our new setup, equipped with a hyperspectral imager, enables hyperspectral fluorescence, optical absorption, dark-field scattering, Raman scattering, and topographic imaging. Recently, we used this capability to visualize pigments in lipid monolayers and within a single live T. lutea cell in solution.[3] For IR s-SNOM, we are working on developing an AFM capable of bottom illumination and collection of IR light to support measurements in aqueous environments. The approach would use a piezoelectric scanner mounted ZnSe prism to enable evanescent wave illumination and collection of scattered IR light. We are also benchmarking the IR s-SNOM with the TERS and hyperspectral imaging modalities on a number of model biological systems including bacteria, collagen, and cytochromes.
This unique AFM-based instrument could be used to investigate a wide range of biomolecules through their characteristic electronic and vibrational signatures, over the nano-meso-micrometer scales. This platform will not only enable recording chemical images of single microbial cells at the subcellular level, but it will also enable mapping entire microbial communities with chemical selectivity.
1. Bhattarai A and El-Khoury PZ (2017) Chem Commun53(53): 7310-7313.
2. Bhattarai A et al. (2017) Nano Lett17(11): 7131-7137.
3. Novikova IV et al. (2017) Chem Phys498-499: 25-32.