A Photostable Silicon Rhodamine Platform for Optical Voltage Sensing

J Am Chem Soc. 2015 Aug 26;137(33):10767-76. doi: 10.1021/jacs.5b06644. Epub 2015 Aug 13.


This paper describes the design and synthesis of a photostable, far-red to near-infrared (NIR) platform for optical voltage sensing. We developed a new, sulfonated silicon rhodamine fluorophore and integrated it with a phenylenevinylene molecular wire to create a Berkeley Red Sensor of Transmembrane potential, or BeRST 1 ("burst"). BeRST 1 is the first member of a class of far-red to NIR voltage sensitive dyes that make use of a photoinduced electron transfer (PeT) trigger for optical interrogation of membrane voltage. We show that BeRST 1 displays bright, membrane-localized fluorescence in living cells, high photostability, and excellent voltage sensitivity in neurons. Depolarization of the plasma membrane results in rapid fluorescence increases (24% ΔF/F per 100 mV). BeRST 1 can be used in conjunction with fluorescent stains for organelles, Ca(2+) indicators, and voltage-sensitive fluorescent proteins. In addition, the red-shifted spectral profile of BeRST 1, relative to commonly employed optogenetic actuators like ChannelRhodopsin2 (ChR2), which require blue light, enables optical electrophysiology in neurons. The high speed, sensitivity, photostability and long-wavelength fluorescence profiles of BeRST 1 make it a useful platform for the noninvasive, optical dissection of neuronal activity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Drug Design
  • Drug Stability
  • Electric Conductivity*
  • Fluorescent Dyes / chemical synthesis
  • Fluorescent Dyes / chemistry*
  • HEK293 Cells
  • Humans
  • Molecular Imaging
  • Neurons / chemistry
  • Optical Phenomena*
  • Rhodamines / chemical synthesis
  • Rhodamines / chemistry*
  • Silicon / chemistry*
  • Sulfonic Acids / chemistry


  • Fluorescent Dyes
  • Rhodamines
  • Sulfonic Acids
  • Silicon