A highly sensitive electrochemical sensor for the detection of trichloroacetic acid (TCA) is developed by subsequent immobilization of phthalocyanine (Pc) and Fe(II) onto multiwalled carbon nanotubes (MWCNTs) modified glassy carbon (GC) electrode. The GC/MWCNTs/Pc/Fe(II) electrode showed a pair of well-defined and nearly reversible redox couple correspondent to (Fe(III)Pc/Fe(II)Pc) with surface-confined characteristics. The surface coverage (Γ) and heterogeneous electron transfer rate constant (ks) of immobilized Fe(II)–Pc were calculated as 1.26×10−10 mol cm−2 and 28.13 s−1, respectively. Excellent electrocatalytic activity of the proposed GC/MWCNTs/Pc/Fe(II) system toward TCA reduction has been indicated and the three consequent irreversible peaks for electroreduction of CCl3COOH to CH3COOH have been clearly seen. The observed chronoamperometric currents are linearly increased with the concentration of TCA at concentration range up to 20 mM. Detection limit and sensitivity of themodified electrodewere 2.0 μMand 0.10 μA μM−1cm−2, respectively. The applicability of the sensor for TCA detection in real sampleswas tested. The obtained results suggest that the proposed system can serve as a promising electrochemical platform for TCA detection.
