Can you imagine being able to witness the start of the enzymatic process that ensures oxygen is carried throughout your blood stream? Can you fathom being able to see the first structural movement of a protein in a timescale of a hundred trillionths of a second? Michael Fayer can. And because this seemingly mild mannered physical chemist has such an active imagination, he has been able to develop laser techniques that can answer piercing biological questions that have eluded us for decades.
The author of two books, including the brand-new "Absolutely Small: How Quantum Theory Explains our Everyday World," Fayer is the David Mulvane Ehrsam and Edward Curtis Franklin Professor of Chemistry at Stanford University. His PhD is from UC Berkeley, and he is a member of the National Academy of Sciences and the American Academy of Arts and Sciences. Fayer is also a Fellow of the APS, the OSA, and the Royal Academy of Chemistry.
Fayer's research focuses on observing incredibly fast chemical processes as they happen. For example, on the picosecond scale, "proteins are constantly undergoing structural fluctuations," he says. "This is what allows the proteins do the various chemical (enzymatic) processes that make life possible. We can use lasers to study the fast motions of proteins."
Fayer and his team use ultrafast, femtosecond (10-15 second) lasers to conduct nonlinear spectroscopic experiments in order to follow the motion of not only proteins but other molecules as well. The advanced lasers chart the course of the expeditious chemical process by recording spectra, in many cases multi-dimensional infrared spectra, as a function of time during the course of the important chemical and physical events.
Fayer's laser experiments have enabled us to better understand water dynamics. "How does water behave? It has such different behavior than other liquids," he notes. Unlike other solidified fluids, ice floats. This is odd behavior for a liquid. But Fayer has applied a laser technique, involving ultrafast laser pulses to examine the vibrational echoes of water in two dimensions, allowing him to study the hydrogen bond network in water and explain how this vital substance maneuvers through various materials. "What water does dynamically tells us how processes work where water is the most common molecule involved," he elucidates. "Up until recently we couldn't do this. Using ultrafast two dimensional, nonlinear (optics), we can (finally) characterize water."
"This work is important in biology, (because) protein folding depends on how water can reorganize around the protein," he continues. Finally, thanks to these laser techniques, scientists can scrutinize the water's dynamics at the surfaces of model cell membranes or in nanoscopic environments found in biological systems that allow cells to function properly. The research also opens conduits of understanding in areas of geology and even the study of fuel cell membranes, where water has to conduct protons through the membranes, he adds.
With the advent of ultrafast nonlinear infrared spectroscopy, we "can examine particular groups of atoms, which are handles for opening up our understanding of molecular dynamical processes," says Fayer. And as more and more laser systems become turnkey and easier to use by non-experts, he predicts the techniques and results of laser research will expand exponentially. The laser pioneer believes that "in the same manner that sophisticated nuclear magnetic resonance (NMR) instruments permeate wide areas of science, ultrafast multi-dimensional infrared spectroscopy will become a common place scientific tool."