An ultrafast molecular rotor based ternary complex in a nanocavity: a potential 'turn on' fluorescence sensor for the hydrocarbon chain

Autor: Sukhendu Nath, Sushant Murudkar, Aruna K. Mora, Tusar Bandyopadhyay, Prabhat K. Singh
Rok vydání: 2015
Předmět:
Zdroj: Physical Chemistry Chemical Physics. 17:5691-5703
ISSN: 1463-9084
1463-9076
DOI: 10.1039/c4cp04636f
Popis: Formation of a ternary complex by an ultrafast molecular rotor (UMR) with a macrocyclic cavitand has been investigated for the sensitive detection of the alkyl chain of a surfactant. A benzothiazole based UMR, Thioflavin-T (ThT), has been used as a fluorescent probe. It is shown that ThT forms a very weak inclusion complex with γ-cyclodextrin (γ-CD) with an association constant of 8.8 M(-1). However, the addition of a small amount of surfactant results in a significant increase in the emission intensity of ThT in γ-CD solution. From detailed steady-state and time-resolved fluorescence measurements and NMR studies, it has been inferred that the addition of the surfactant results in the formation of a ternary complex through the inclusion of its alkyl chain inside the γ-CD nanocavity. In such a ternary complex, the non-radiative torsional motion in ThT is largely prevented due to a large increase in the frictional force inside the nanocavity and results in a significant fluorescence enhancement. The formation of the binary and the ternary complexes in the present system has been further supported by the molecular docking and subsequent molecular dynamics simulation studies. The present result indicates that the inclusion complex with an UMR as a guest could be a potential candidate for the efficient detection of insoluble organic molecules, especially hydrocarbons.
Databáze: OpenAIRE