A multi-channel sensor based on 8-hydroxyquinoline ferrocenoate for probing Hg(II) ion

A new sensing molecule 8-hydroxyquinoline ferrocenoate (Fc-Q) which combines ferrocene and 8-hydroxyquinoline moieties was synthesized and applied as a multi-channel sensor for the detection of Hg2+ ion. Fc-Q can coordinate with Hg2+ to give colorimetric, fluorescent and electrochemical responses. Upon complexation with Hg2+ ion, the characteristic absorption peak is red-shifted (Δλ = 45 nm), the fluorescent intensity is quenched at 303 nm, and the oxidation peak is cathodic shifted (ΔE1/2 = −149 mV). Quantitatively analyzed Hg2+ ions at the range of ppb level could be achieved by electrochemical response. For the practical application of sensing Hg2+ in real world water, Fc-Q modified screen-printed carbon electrodes were obtained for facile, sensitive, and on-site analysis of Hg2+.