Simultaneous detection of lysosomal SO2 and viscosity using a hemicyanine-based fluorescent probe.

[Display omitted] • A morpholine-containing sensor for the ratiometric fluorescent detection of SO 2 has been developed. • The sensor could have dual-response for SO 2 and viscosity. • The sensor could be utilized to detect SO 2 and viscosity in the lysosomes of living C6 glioma cells. The changes in sulfur dioxide and viscosity of lysosomes are significant indicators in physiological processes and the cell microenvironment. This study aimed to synthesize a hemicyanine-based probe for simultaneous detection of SO 2 and viscosity. The probe could not only rationally detect sulfur dioxide in a semi-aqueous solution with high sensitivity (limit of detection = 0.78 μM) and fast response (within 30 s) but also monitor viscosity via fluorescence emission enhancement at 580 nm. Further, the dual-response probe was successfully used to image SO 2 and viscosity in the lysosomes of living cells. [ABSTRACT FROM AUTHOR]