7-Amino-2-( <i>N</i> , <i>N</i> -dimethylamino)quinazoline: a small, bright, easily synthesized scaffold for pH sensors

This study reports a series of pH-responsive 2-(<i>N</i>,<i>N</i>-dimethylamino)quinazolines bearing amino substituents at position 7. These compounds exhibited tunable fluorescence (FL) enhancements under both acidic and basic conditions. Due to their small size, ease of synthesis, and strong fluorescence, these probes show promise for the development of pH sensors suitable for biological or environmental applications.