Two labs at the University of Utah’s Department of Chemistry joined forces to improve imaging tools that may soon enable scientists to better observe signaling in functioning cells and other molecular-scale processes central to life.

Rodrigo Noriega, assistant professor of chemistry and co-author of the study.

The Noriega and Hammond labs, with complementary expertise in materials chemistry and chemical biology, made critical discoveries announced this month in the Journal of the American Chemical Society that could advance this goal. Their joint project was kickstarted through a team development grant from the U College of Science and the 3i Initiative to encourage faculty with different research interests to work together on big-picture problems.

“We’re trying to develop a new kind of imaging method, a way to look into cells and be able to see both their structural features, which are really intricate, while also capturing information about their activity,” said co-author Ming Hammond, a professor of chemistry. "Current methods provide high-resolution details on cellular structure but have a challenging ‘blind spot’ when it comes to function. In this paper, we study a tool that might be applied in electron microscopy to report on structure and function at the same time.”

Biological samples often need “markers,” or molecules that are the source of detectable signals, explained co-author Rodrigo Noriega, an assistant professor of chemistry. A widely used type of markers are flavoproteins which, when photoexcited, trigger a chemical reaction that yields metal-absorbing polymer particles whose high contrast in electron microscopy is easily seen.

Scientists had long assumed that a mechanism involving singlet oxygen generation, a special kind of reactive oxygen species, was at play. However, the U team found that electron transfer between the photoexcited marker and the polymer building blocks is the main contributor to the process.