Ultra-bright and -stable red and near-infrared squaraine fluorophores for in vivo two-photon imaging

PLoS One. 2012;7(12):e51980. doi: 10.1371/journal.pone.0051980. Epub 2012 Dec 14.

Abstract

Fluorescent dyes that are bright, stable, small, and biocompatible are needed for high-sensitivity two-photon imaging, but the combination of these traits has been elusive. We identified a class of squaraine derivatives with large two-photon action cross-sections (up to 10,000 GM) at near-infrared wavelengths critical for in vivo imaging. We demonstrate the biocompatibility and stability of a red-emitting squaraine-rotaxane (SeTau-647) by imaging dye-filled neurons in vivo over 5 days, and utility for sensitive subcellular imaging by synthesizing a specific peptide-conjugate label for the synaptic protein PSD-95.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cyclobutanes / chemistry*
  • Cyclobutanes / metabolism
  • Fluorescent Dyes / chemistry*
  • Fluorescent Dyes / metabolism
  • Microscopy, Fluorescence, Multiphoton / methods*
  • Nerve Tissue Proteins / chemistry
  • Nerve Tissue Proteins / metabolism
  • Neurons / chemistry
  • Neurons / metabolism
  • Phenols / chemistry*
  • Phenols / metabolism
  • Photons
  • Rotaxanes / chemistry
  • Rotaxanes / metabolism
  • SAP90-PSD95 Associated Proteins
  • Synapses / chemistry
  • Synapses / metabolism
  • Xenopus laevis

Substances

  • Cyclobutanes
  • Fluorescent Dyes
  • Nerve Tissue Proteins
  • Phenols
  • Rotaxanes
  • SAP90-PSD95 Associated Proteins
  • squaraine