Dual-mode tunable viscosity sensitivity of a rotor-based fluorescent dye

The design and fabrication of new type viscosity sensor oil molecular scale will enrich the detection means in both physical and life sciences In this work, a rotor-containing fluorescent dye was prepared, which can reveal a typical viscosity-sensitive behavior due to the environment-induced non-radiative decay The viscosity-sensitive behavior of this dye Could be tunable (locked and activated) in aqueous environment, either with the reversible light-driven trans/cis-photoisomerization of the cyanostilbene moiety, or with the reversible assembly/disassembly process of beta-cyclodextrin (beta-CD) to the rotor part Such dual-mode tunable viscosity sensitivity can be well distinguished by fluorescent spectra A slope method, on double-logarithmic plots of the fluorescent signal to the corresponding environmental viscosity, makes a quantitative estimation to the tunable viscosity sensitivity. featuring the 'Activated' and the 'Locked' State in this molecular-scale viscometer (C) 2009 Published by Elsevier Ltd