Ivan Aprahamian
Dartmouth College, NH·Chemistry
Molecules that change shape when hit by light, or when triggered chemically, can act as tiny on/off switches. These projects build switches from hydrazones, small organic molecules that are simple to make and modify.
- Fields
Chemistry
Materials Science
Biophysics
- Topics
molecular switches
photoswitches
hydrazones
- Grants
- 3 known grants, through Jun 2031
What they work on
- Improve the brightness, water solubility, cell compatibility and color range of light-switchable hydrazone dyes through structure-property studies guided by density functional theory (DFT) calculations, spectroscopy and bio-imaging.
- Develop switchable hydrazone fluorophores for multiplexed live-cell super-resolution microscopy (nanoscopy), using feedback between imaging results and molecular design.
- Design switchable fluorophores that selectively bind soluble amyloid-beta oligomers, to image their structures, dynamics and interactions with super-resolution microscopy.
- Use halogen bonding to strengthen interactions between light-switchable hydrazone chiral dopants and liquid crystal hosts, enabling precise light control of the color reflected by the liquid crystal.
- Create new chiral switch designs, such as macrocyclic hydrazones and tribenzotriquinacene scaffolds, and test switchable dopants for controlling reflection in ferroelectric liquid crystals.
- Determine the kinetic and thermodynamic factors that set the threshold of zinc-triggered negative feedback loops built from hydrazone switches, then couple loops to make precise amounts of coordination cages and polymers.
- Develop light-reversible ligands to control zinc levels and photoacids or photobases to tune pH, so that light can regulate an entire reaction cascade.
More about the research
They use them for three purposes: light-controlled glowing dyes for very high-resolution microscopy, additives that set the color reflected by liquid crystals, and chemical networks in which switches regulate one another.
Why it matters
Brighter, cell-friendly switchable dyes could let biologists watch molecular processes in living cells at nanometer resolution and image amyloid-beta oligomers, which could help efforts toward diagnostics and therapies for neurodegenerative diseases. Light-tunable liquid crystals could enable low-energy displays, smart price tags, anti-counterfeiting devices and adaptive camouflage, while switch-controlled feedback loops add basic understanding of autonomously regulated chemical systems.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
Closest labs
Xiaocun Lu
Clarkson University, NY·Chemistry
Build a library of molecular force gauges, molecules that change color or glow under force, to measure compressive and tensile forces in cells and biological targets.
Mark Lipke
Rutgers University-New Brunswick, NJ·Chemistry
Measure how water trapped inside redox-active porphyrin nanocages changes the acidity of acid-bearing guest molecules and their combined proton-electron transfer, using electrochemistry and 1H NMR to quantify water uptake.
Lan Li
Boise State University, ID·Materials Science
Generate dye structure-property datasets using density functional theory (DFT) and time-dependent DFT, which simulate molecules and their light-excited states.
The school
Dartmouth College: 16 labs on PI Pages, $418M a year on research, 104 research doctorates a year.
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