A triphenylamine-thiophene-based fluorescent probe for the dual-channel detection and imaging of hypochlorite and viscosity in live cells

In this research, a new triphenylamine-thiophene-based fluorescent probe, denoted as TTD, was constructed for simultaneous detection of viscosity and hypochlorite (ClO−) with dual-response signals. The hindrance of intramolecular bond rotation within TTD in a high-viscosity environment turns on the probe's emission at 600 nm, resulting in strong red fluorescence. Simultaneously, the oxidation of the imine moiety to the aldehyde product, induced by ClO−, leads to substantial emission enhancement at 460 nm, generating vivid blue fluorescence. As a result, TTD can be employed for the dual-color visualization of changes in viscosity and ClO− levels, demonstrating good selectivity. TTD has been applied to image the elevated level of viscosity induced by nystatin, rotenone or erastin as well as exogenously introduced ClO− in living cells. Importantly, from two independent emission channels, TTD is capable of monitoring both ClO− and viscosity fluctuations within live cells during the inflammatory response triggered by lipopolysaccharide (LPS).