Electrochemical deposition of the new manganese(II) Schiff-base complex on a gold template and its application for dopamine sensing in the presence of interfering biogenic compounds

• Template synthesis of new Mn(II) complex 1 and its crystal structure are reported.
• Benzimidazole moieties of 1 are crucial to form SAMs on gold electrode.
• Novel 1-Au composite was applied for quantitative determination of dopamine (DA).
• 1-Au sensor can be used in the presence of interferents like ascorbic and uric acids.

Facile and efficient template synthesis of new manganese(II) complex [Mn2(H2L)2](ClO4)2 (1) and its crystal structure are reported. Self-assembly leads to the formation of dinuclear, phenoxo-bridged closed species via exploitation of both binding subunits of the in situ formed new Schiff-base ligand. Gold electrode modified with self-assembled monolayers (SAMs) composed of synthesized complex 1 was applied as a voltammetric sensor for quantitative determination of dopamine (DA) in the presence of ascorbic (AA) and uric acids (UA). The linear relationship between the current response of dopamine at the potential of peak maximum and the concentration was found over a wide analyte concentration range (R2≥0.993, 1×10−10–8.5×10−4 M) with a very good sensitivity (4.11 A cm−2 M−1 at dE/dt=0.1 V s−1), high detection limit (6.8×10−9 M) and excellent reproducibility. It has been proven that current peaks of dopamine, ascorbic and uric acids were clearly separated from each other, thus enabling selective detection of these compounds coexisting in a mixture.

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