Simple-structured, hydrazinecarbothioamide derivatived dual-channel optical probe for Hg2+ and Ag+

A type of simple-structured, hydrazinecarbothioamide-containing Schiff-base derivative, 2-(4-(diphenylamino)benzylidene)hydrazinecarbothioamide (M1), was synthesized through condensation reaction between 4-(diphenylamino)benzaldehyde and thiosemicarbazide. In the mixture of DMSO/H2O (DMSO/H2O=9:1(v:v), pH=4.5), distinct “turn-off” fluorescence alterations of M1 were observed upon the addition of Hg2+, and the addition of Ag+ induced fluorescence bathochromic shift. The detection limits of Hg2+ and Ag+ reach~0.19 μM and ~0.59 μM, respectively, as evaluated by the detailed fluorescence response of M1 toward incremental target ions. The different extent of photo-induced electron transfer (PET) between M1 and these two ions might be the plausible reason for such different optical response behaviors.