Carbon and diamond paste microelectrodes based on Mn(III) porphyrins for the determination of dopamine.

Three Mn(III) porphyrins were used for the design of carbon paste and diamond paste based microelectrodes, which were employed for the determination of dopamine in pharmaceutical and biological samples using differential pulse voltammetry (DPV). The limits of detection lie between 1.6 x 10(-13) and 2.0 x 10(-6) mol L(-1) while the sensitivities were between 230 pA micromol L(-1) and 3.24 microA mol L(-1). Dopamine was recovered reliable from pharmaceutical and biological samples in percentages higher than 91.00% and 92.00%, respectively. The surface of the microelectrodes can easily be renewed by simple polishing, obtaining a fresh surface ready for use in a new assay. Copyright 2010 Elsevier B.V. All rights reserved.