Related Experiment Video
Updated: Feb 2, 2026

Fluorescence Lifetime Imaging of Molecular Rotors in Living Cells
Published on: February 9, 2012
An Ultrafast Molecular-Rotor-Based Fluorescent Turn-On Sensor for the Perrhenate Anion in Aqueous Solution
Akshat M Desai1, Prabhat K Singh1,2
1Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India.
Abstract:
Devising sensors for the perrhenate anion in aqueous media is extremely challenging, and has seldom been reported in the literature. Herein, we report a fluorescence turn-on sensor for the perrhenate anion in aqueous media based on the aggregation-induced emission of a popular ultrafast molecular rotor dye, Thioflavin-T. The selective response towards the perrhenate anion has been rationalized in terms of matching water affinity, with the weakly hydrated perrhenate anion spontaneously forming a contact ion pair with the weakly hydrated ultrafast molecule-rotor-based organic cation, Thioflavin-T, which in turn leads to an aggregate assembly that provides a fluorescence turn-on response towards perrhenate. The sensing response of Thioflavin-T has been found to be quite selective towards the perrhenate anion when tested against anions that are ubiquitously present in the environment, such as chloride, nitrate, and sulfate anions. The formation of self-assembled Thioflavin-T aggregates has also been investigated by time-resolved emission and temperature-dependent measurements.
Related Concept Videos
Chemical Reactions in Aqueous Solutions
Leveling Effect and Non-Aqueous Acid-Base Solutions
The Leveling Effect of a Solvent
A generic acid (HA) reacts with the generic base (B-) to yield the corresponding conjugate base (A-) and conjugate acid (HB):
Aqueous Solutions and Heats of Hydration
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
Determining the pH of Salt Solutions
Weak Base Solutions
π Molecular Orbitals of the Allyl Cation and Anion

