A chemosensor for heavy-transition metal ions in mixed aqueous–organic media

A new chemosensor (L1) is synthesized and its spectral response was screened with most alkali, alkaline earth, transition and lanthanide metal ions in THF–water (2:3, v/v, pH 7.2, 20 mM HEPES buffer) medium. This is found to bind four different transition metal ions such as Hg2+, Cu2+, Ag+ and Ni2+ in mixed aqueous solution at pH 7.2; while binding affinity towards the Hg2+ is found to be an order of magnitude higher as compared to other three cations mentioned. Experimental results reveal that the L1 could be used for colorimetric detection of Hg2+, present in the lower organism like Pseudomonas putida.