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Noriega Research Group

Our group employs ultrafast laser spectroscopy tools to establish relationships between chemical identity, molecular-scale dynamic processes, and macroscale observables with the purpose of directing materials development. We are particularly interested in molecular systems because a large number of chemical variations can yield a seemingly boundless portfolio of materials with tunable properties. Most functional materials operate in the condensed phase and thus experience the presence of nearby molecules; this local environment has substantial effects on their behavior. Our goal is to tailor the molecular environment in order to tune the properties of functional materials.

Dynamic molecular environments span a large range of complexity, and active projects in our group investigate a variety of chemical systems ranging from bimolecular reactive species in solution, to functionalized electrochemical interfaces, and large protein-RNA complexes. To uncover the role of molecular-scale events that can direct the evolution of and be affected by much slower processes (e.g., local solvation and global supramolecular reorganization), we employ laser spectroscopies across the electromagnetic spectrum that can monitor dynamics spanning from sub-picosecond to minutes.

Molecular recognition and protein-RNA complex formation

© The Royal Society of Chemistry 2021

Using time-resolved photoluminescence (TRPL) to measure light emitted by probe labeling RNA substrates, it is possible to detect the signatures of binding as they alter the probe's photophysics (e.g., fluorescence lifetime, transient anisotropy). In this way, one can differentiate between different modes of molecular recognition employed by large, multidomain proteins (such as Dicer-2, left)

Our group is also developing ways to control the local environment in which binding takes place, and leveraging the temporal resolution of single-photon detection to follow fluctuations related to complex formation and stability.

We are grateful for the support of this project by the National Science Foundation! (award 2123516).


Multimodal probe of electrified interfaces


© The Royal Society of Chemistry 2020

Electrochemical processes occur within a complex environment involving electrode surfaces, solvent molecules, ions, and free and surface-bound species. Combining expertise in materials science and physical chemistry, we devised an experimental platform that incorporates mid-IR plasmon reflectivity and time-resolved fluorescence measurements of thin films at the surface of a working electrode. 

In our group, we employ these complementary tools to probe molecular-scale details of the dynamic microenvironment experienced by molecules situated at the interface between a solid electrode and a liquid electrolyte – including their solvation state, local ion concentration, and collective macromolecular motions.


Photochemistry in solution


© 2022 American Chemical Society

Using ultrafast UV photochemistry, we identified transient radical ion species that efficiently equilibrate with their environment and then participate in a chemical transformation from an electronic ground state. This observation of a relaxed, solvated intermediate suggested that equilibrium solute-solvent interactions can be used to modulate the reactivity of transient species. 

Solvent-mediated reactive pathways are an important degradation channel for radical ions used in energy conversion and storage materials, and we are exploring ways to tune their local environment to reduce the degradation of redox-active species within complex electrolyte environments.

Another topic of interest to our group is to optimize the photophysics of sensitizer chromophores in order to optimize the light-triggered polymerization of melanin-like polymers (thanks to the U. of Utah Health 3i Initiative for their support of this exciting new research direction!)


Contact us to learn more about our work at the interface of spectroscopy and materials chemistry.


Last Updated: 8/30/22