A new sensitive and selective detection of Ga by thiophene-based 'turn-on' fluorescent chemosensor.

We designed a thiophene-based fluorescent chemosensor DHTC ((E)-2-([3,5-dichloro-2-hydroxybenzylidene]amino)thiophene-3-carboxamide) for detecting gallium (Ga ). DHTC could probe Ga using fluorescence enhancement. The limit of detection for Ga by DHTC was 0.39 μM. The binding mode of DHTC to Ga was determined as a 1:1 ratio from analysis by Job's plot and electrospray ionization-mass spectrometry (ESI-MS). In addition, DHTC could selectively detect Ga using test kits. The sensing process of Ga by DHTC was presented using ultraviolet-visible light titration, Job's plot, ESI-MS, H nuclear magnetic resonance titration, and density functional theory calculation.