Colorimetric Cu Detection of (1,2)-1,2-Bis((1-pyrrol-2-yl)methylene)hydrazine Using a Custom-Built Colorimeter.

The compound (1,2)-1,2-bis((1-pyrrol-2-yl)methylene)hydrazine () was investigated for its chemosensor application. The colorimetric response of with various ions was investigated, and the selective optical change upon mixing with Cu was found. The Cu binding stoichiometry of derived from Job's plot and the study give us the tentative structural detail of the binding mode of and Cu being 1:1. The binding constant between and Cu from the Benesi-Hildebrand plot was 1.49 × 10 M. The limit of detection of in Cu detection was 0.64 μM (0.040 ppm), which is much lower than the WHO and US EPA maximum allowable Cu level in drinking water (2 and 1.3 ppm, respectively). The custom-built colorimeter demonstrates a good linear relationship between Cu concentration and electrical resistance (Ω) upon -Cu ion binding.