A multi-functional chemosensor for highly selective ratiometric fluorescent detection of silver(I) ion and dual turn-on fluorescent and colorimetric detection of sulfide.

A multi-functional chemosensor as silver and sulfide detector was synthesized by the combination of octopamine and 4-dimethylaminocinnamaldehyde. Sensor exhibited a ratiometric fluorescence emission for Ag from blue to sky. The binding mode of and Ag turned out to be a 1 : 1 ratio as determined using Job plot and electrospray ionization (ESI) mass spectral analyses. The sensing mechanism of with silver ion was unravelled by H NMR titrations and theoretical calculations. Sensor also discerned sulfide by enhancing fluorescence intensity and changing colour from yellow to colourless in aqueous solution. The sensing properties of toward S were investigated by using ESI-mass analysis, Job plot and H NMR titrations. Moreover, could be used as a detector for sulfide in a wide pH range.