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Abstract
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Lead-doped carbon ceramic electrode as a new type of renewable composite electrode was prepared by mixing the lead
powder with electrode matrix before gelation. Pb on the electrode surface was then converted to lead dioxide by the potential
scanning of the composite electrode in 0.1 M NaOH solution in the range of − 0.3 to 0.7 V versus SCE. The composition
and morphology of the electrodes were studied by energy dispersive X-ray spectrometry, scanning electron microscopy,
and atomic force microscopy techniques. Cyclic voltammetry and chronoamperometry techniques were also used to study
the electrocatalytic activity of the modified electrode toward the oxidation of the l-tyrosine. The best results were obtained
at a working potential of 0.45 V (vs. SCE) in 0.1 M NaOH solution. The sensor exhibited a good linear response in the
range of 5–1458 μM with a coefficient of determination of 0.9963. The detection limit was 0.77 μM, and sensitivity was
37.4 μA mM−1. In addition, the modified electrode showed high stability and interference-free response for to detection of
the l-tyrosine.
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