Design of fluorescence turn-on sensors with novel response mechanism based on C=N isomerization

A series of new type naphthalimide-based fluorescent molecules linking aniline-like groups via a coupling chain with -C=N- structure were developed as novel fluorescence chemosensors with high sensitivity and selectivity toward H+ in solution and acidic atmosphere as well as Al3+ in the presence of other cations. The fluorescence turn-on mechanism was studied and proved to be based on the C=N isomerization. For these fluorescent molecules with donor-acceptor structure, their luminescent wavelength and photophysical properties can be dominated by adjusting the structure of aniline-like groups and the chain length connecting with naphthalimide. All of these fluorescent molecules emitted strong solid-state fluorescence due to their inherent twisted geometries, and exhibited excellent thermal stability, which is beneficial for their application at high temperature.

Automated summary

Novel naphthalimide-based fluorescent molecules have been developed as fluorescence chemosensors with high sensitivity and selectivity towards H+ and Al3+ due to their C=N isomerization-based fluorescence turn-on mechanism. By adjusting the structure and chain length, their photophysical properties can be controlled, leading to strong solid-state fluorescence and excellent thermal stability for potential high-temperature applications.