RESEARCH / ■ THEME II · CURRENT WORK · COLLABORATIVE
Polaritonic and plasmonic control of molecular behaviour
Can hybridising a molecular vibration with a confined optical mode measurably change how a molecule moves and reacts — and if so, under what conditions does the effect reproduce?
Nearly all vibrational strong coupling chemistry so far has used high-Q dielectric microcavities. They work, but they constrain which molecules and conditions can be studied, and they reveal only the final rate — not the motion behind it. Plasmonic metasurfaces lift both constraints: they are open-faced, continuously tunable across the mid-infrared, and the same field enhancement that produces the coupling amplifies the 2D IR signal, so the measurement can watch what the coupling actually does to molecular motion.
The reported rate effects remain disputed, and the enzyme result that motivates the most ambitious version of this work has not been independently reproduced. My plan is staged accordingly: establish the platform and coupling signatures, run a controlled rate test, and attempt the enzyme experiment only once a coupling-induced effect is demonstrated in my own hands. A rigorous negative result would itself constrain the theory, and is worth having.
Methods
- Fabry–Pérot microcavity fabrication and characterisation
- Plasmonic and surface-lattice-resonance metasurfaces
- Broadband, polarisation-controlled 2D IR
- Angle-resolved dispersion measurement
- Enzyme kinetics with isotopically labelled substrates
Publications in this theme
1 records → publicationsProjects in this theme
- Why it matters
- Reactivity is normally steered with composition, temperature or a catalyst. Vibrational strong coupling claims a different lever: the electromagnetic vacuum itself, with reports of slowed ground-state reactions and altered enzyme turnover — all in the dark. The field is contested. Key rate effects have resisted replication, one prominent result was retracted, and transition-state theory predicts no change. That is exactly why it needs dynamics-resolved, reproducibility-controlled measurement.
- My contribution
- At Michigan I applied 2D IR to enzyme-catalysed reactions under vibrational strong coupling in optical cavities. At Austin, using tunable indium tin oxide nanocrystal metasurfaces, I showed that even in the lossy weak-coupling regime a metasurface accelerates the interfacial vibrational dynamics of an overlying polymer by up to sevenfold, reshapes vibrational coherence and opens directional energy-transport channels.
- What we found
- Tunable plasmonic metasurfaces are a scalable, chemically agnostic way to engineer vibrational dynamics: no high-finesse cavity or special molecular system is needed to produce a large, measurable effect on structural dynamics and energy transport.
- Where it goes next
- First, metasurfaces that reach genuine strong coupling, with unambiguous signatures — anticrossing, concentration scaling of the Rabi splitting, resolved polariton bands. Second, a reproducibility-grade test of whether VSC changes the rate of a model reaction, with a full detuning series and internal controls; a clean negative result counts. Third, and only then, whether VSC modulates aldehyde dehydrogenase catalysis, using Swain–Schaad analysis of deuterated substrates.