Selective recognition of Cu (II) and Fe (III) using a pyrene based chemosensor

A pyrene-based colorimetric chemosensor 1-(pyren-1-yl)-N,N-bis-(pyridine-2-ylmethyl)methanamine (1) was synthesised for selective detection of Cu (II) and Fe (III) over the other metal cations Ni2+, Mg2+, Cd2+, Hg2+, Na+, K+, Ca2+, Co2+, Cr3+, Pb2+ and Zn2+. The significant changes in UV-vis absorption band of receptor 1 and the emergence of 660nm band in presence of Cu2+ ion indicates the selective binding of Cu2+ ion as compared to other metal cations which could easily be identified from the naked eye strong colour change. Job plots suggest a 1:1 and 2:1 stoichiometric binding of Cu2+ and Fe3+, respectively, which was evidenced by ESI-MS analysis. Chemosensor 1 explores a cost-effective and selective colorimetric sensor for naked eye detection of trace amount of Cu2+ and Fe3+ ions in presence of other metal cations.