Viscosity sensitive near-infrared fluorescent probes based on functionalized single-walled carbon nanotubes.

Abstract

A viscosity-sensitive fluorescent probe is demonstrated by grafting a rotatable 4-N,N'-dimethylaniline group on (6,5) single-walled carbon nanotubes. The rotation of the grafted group is constricted by solution viscosity, causing changes in the photoluminescence behaviors of the nanotubes. This enables a highly sensitive fluorescent probe for determining solution ratiometric viscosity in the biologically transparent second near-infrared region.