Sensor eletroquímico para determinação da β-lapachona, derivado do lapachol.

Abstract

This work presents a proposal for an electrochemical sensor, formed by a glassy carbon electrode modified with a supramolecular porphyrin, the {MnTPyP[RuCl3(dppb)]4}+. The precursors used for the supramolecular porphyrin synthesis were: the peripheral aqua complex mer-[RuCl3(dppb)(H2O)] and the metalated porphyrin [Mn-TPyP]+ in the ratio of 4 to 1, respectively. All complexes were synthesized using procedures known in the literature. The modified electrode containing the supramolecular porphyrin was obtained by an electropolymerization process on the vitreous carbon electrode‟s surface using the cyclic voltammetry technique. This modified electrode was then applied as a voltammetric sensor for the identification and quantification of β-lapachone, obtaining a detection limit (LD) of 22,8 μmolL-1 and a quantification limit (LQ) of 76,1 μmolL-1 when cyclic voltammetry was used and values of LD and LQ of 77,3 μmolL-1 and 257,8 μmolL-1, respectively, when using the square-wave voltammetry technique