Gary Zabow1, 2, Stephen Dodd1, Alan Koretsky1
1LFMI, NINDS, National Institutes of Health, Bethesda, MD, United States; 2Physical Measurements Laboratory, NIST, Boulder, CO, United States
Microengineered multi-spectral contrast agents generate their different spectral signals due to their different geometrical shapes. If the microstructure shapes were to change dynamically in response to some local physiological condition, they could give a changing spectral, or color, signal that would effectively serve as a real-time readout monitoring the particular physiological condition of interest. Here we give an example of this, using microstructures based on pH-sensitive hydrogels that dynamically change their shape under different pH conditions, forming an MRI pH-meter.