Highly sensitive naphthalimide based Schiff base for the fluorimetric detection of Fe.

A simple 1,8-naphthalimide based Schiff base probe ()-6-((4-(diethylamino)-2-hydroxybenzylidene)amino)-2-(2-morpholinoethyl)-1-benzo[de]isoquinoline-1,3(2)-dione (NDSM) has been designed and synthesized for the specific detection of Fe based on a fluorimetric mode. The absorbance of NDSM at 360 nm increased significantly in acetonitrile : water (7 : 3, v/v) medium only in the presence of Fe ions with a visible colour change from yellow to golden yellow. Likewise, fluorescence emission intensity at 531 nm was almost wholly quenched in the presence of Fe.

Phenanthridine based rapid "turn-on" fluorescent sensor for selective detection of Th ion and its real-time application.

A new and highly sensitive and selective phenanthridine based sensor, 9-(7,8,13,14-tetrahydrodibenzo[a,i]phenanthridin-5-yl)benzo[h]quinolin-10-ol (PHBQ), was developed for the fluorescent ''turn-on'' detection of Th ion in acetonitrile: water (8:2) medium. The fluorescence intensity of PHBQ diminished in the region of pH 1 to 3 and could be recovered by adjusting the pH to above 4. The sensor PHBQ showed distinct spectral changes in response to Th ion over other competitive metal ions.

Fused pyrazole-phenanthridine based dyads: synthesis, photo-physical and theoretical studies, and live cell pH imaging.

The arrangement of small sized molecules with a scaffold structure plays an active role in the fields of sensors and health care. An efficient molecular design strategy for four pyrazole-phenanthridine based D-π-A luminophores, denoted as 2a, 2b, 2c and 2d was developed to investigate the effect of acid on the photo-physical properties of these dyes. Photo-physical studies of the synthesized probes showed distinct absorption and emission under various pH conditions.