Voltammetric metal cation sensors based on ferrocenylthiosemicarbazone

Electrochemical studies on redox-active ferrocenylthiosemicarbazone L1–4 were carried out in acetonitrile in the presence of various metal cations. Electrochemical investigation have demonstrated that the binding of Cu2+, Hg2+ and Ni2+ guest cations by L1–4 results in large shifts of respective Fc/Fc+ redox couple to more positive potentials. Moreover, for compound L4, significant fluorescence enhancement was found in the presence of the Cu2+, and this suggests it can act as a biresponsive fluorescent and electrochemical chemosensor for Cu2+.