Visualising Chemistry at the Single Molecule Level

Seminar series
Organic Colloquium
Thu, Feb 13 4:00pm
CS 76
Speaker Professor Gonzalo Cosa
McGill University
Department of Chemistry

Abstract: Single molecule fluorescence (SMF) and related super-resolution single molecule localization microscopy (SMLM) imaging methodologies are transformative tools in biology, chemistry, and physics. Relying on monitoring single fluorophores over time, key to successful SMF experiments are high signal intensities, extended survival times and controlled switching. Our own work explores the design and optimization of fluorophores photochemical and photophysical behavior to enhance their signal stability, photon budget and improve photoswitching. We next exploit the rational design of chemical probes, and photochemical/photophysical schemes to gain a molecular level understanding of chemical processes of fundamental and technological relevance. In this presentation I will describe recent progress on understanding the photochemistry behind cyanine dye photostability and photoswitching.1 I will illustrate how enhanced photochemical and photophysical properties enable us in turn to explore the assembly dynamics, structure, morphology and resilience of wireframe DNA nanomaterials that are studied at the single molecule/particle level. I will also describe live ell imaging work where we exploit newly developed activatable BODIPY dyes to monitor lipid peroxyl radicals, electron transport in membranes, and reaction of lipid derived electrophile analogues with cellular nucleophiles. I will provide recent examples for the use of the probes in bio-analytical assays and in state-of-the-art fluorescence imaging studies including super resolution imaging based on SMLM, of reactions in biological milieu. In all cases, emphasis will be placed on the enormous opportunities that single molecule fluorescence provides to interrogate and study chemical reactions of interest.