Isomerically Pure Tetramethylrhodamine Voltage Reporters

Authors:
Publisher website
Google Scholar
Abstract
We present the design, synthesis, and application of a new family of fluorescent voltage indicators based on isomerically pure tetramethylrhodamines. These new Rhodamine Voltage Reporters, or RhoVRs, use photoinduced electron transfer (PeT) as a trigger for voltage sensing, display excitation and emission profiles in the green to orange region of the visible spectrum, demonstrate high sensitivity to membrane potential changes (up to 47% ΔF/F per 100 mV), and employ a tertiary amide derived from sarcosine, which aids in membrane localization and simultaneously simplifies the synthetic route to the voltage sensors. The most sensitive of the RhoVR dyes, RhoVR 1, features a methoxy-substituted diethylaniline donor and phenylenevinylene molecular wire at the 5′-position of the rhodamine aryl ring, exhibits the highest voltage sensitivity to date for red-shifted PeT-based voltage sensors, and is compatible with simultaneous imaging alongside green fluorescent protein-based indicators. The discoveries that sarcosine-based tertiary amides in the context of molecular-wire voltage indicators prevent dye internalization and 5′-substituted voltage indicators exhibit improved voltage sensitivity should be broadly applicable to other types of PeT-based voltage-sensitive fluorophores.
Funding Information
  • U.S. Department of Health and Human Services (R00 NS07581)
  • University of California Berkeley
  • Alzheimer's Association (2016-NIRG-394290)
  • March of Dimes Foundation (5-FY16-65)

This publication has 18 references indexed in Scilit: