Molecular rotors—fluorescent biosensors for viscosity and flow

Viscosity is a measure of the resistance of a fluid against gradients in flow (shear rate). Both flow and viscosity play an important role in all biological systems from the microscopic (e.g., cellular) to the systemic level. Many methods to measure viscosity and flow have drawbacks, such as the tedious and time-consuming measurement process, expensive instrumentation, or the restriction to bulk sample sizes. Fluorescent environment-sensitive dyes are known to show high sensitivity and high spatial and temporal resolution. Molecular rotors are a group of fluorescent molecules that form twisted intramolecular charge transfer (TICT) states upon photoexcitation and therefore exhibit two competing deexcitation…

• NI
  National Institutes of Health