Lead Ruthenate Pyrochlore Formed in Clay for Sensitive Determination of Dopamine

Natural iron‐intercalated clay (nontronite, SWa‐1) was converted into a more efficient catalyst by formation of lead ruthenate pyrochlore (Py, Pb₂Ru_2?xPb_xO_7?y) directly inside the matrix. The new material can take advantage of the electrocatalytic properties of both Py and nontronite and can even generate new catalytic active sites due to interaction of Py and nontronite. The combination of these two interesting catalysts results in a more reactive electrode (designated as SWa‐1/PyCME) for electroanalytical applications. The preparation and characterization of the SWa‐1/PyCME as well as its electrocatalytic behavior toward the oxidation of dopamine are described in this study. Surface saturation kinetics in terms of Michaelis‐Menten kinetics suited well the oxidation of dopamine on this modified electrode. Under optimized conditions, the detection limit (S/N= 3) was 0.54 nM by square‐wave voltammetry.