A zucchini-peroxidase biosensor applied to dopamine determination.
A biosensor modified with peroxidase from crude extract of zucchini (Cucurbita pepo) was developed for the determination of dopamine in pharmaceutical samples. This enzyme catalyses the oxidation of dopamine to dopaminequinone, in presence of hydrogen peroxide, which the electrochemical reduction can be followed at a peak potential of -0.02 V. The recovery of dopamine from the samples ranged from 94.8% to 106% and a rectilinear analytical curve for dopamine concentration from 5.0 x 10(-4) to 3.0 x 10(-3) mol L-1 (r=0.9982) was obtained. The detection limit was 2.6x10(-5) mol L-1 and the relative standard deviation was less than 1.2% for 7.9 x 10(-4) mol L-1 dopamine in 0.1 mol L-1 phosphate buffer solution at pH 6.0 (n=10).
Lupetti
Karina Omuro
KO
Departamento de Química, Universidade Federal de São Carlos, São Carlos-SP, Brazil.
Ramos
Luiz Antônio
LA
Vieira
Iolanda Cruz
IC
Fatibello-Filho
Orlando
O
D015374:Biosensing Techniques; D002626:Chemistry, Pharmaceutical; D028464:Cucurbita / Q000737:chemistry / Q000201:enzymology*; D004298:Dopamine / Q000032:analysis*; D004563:Electrochemistry; D006861:Hydrogen Peroxide / Q000494:pharmacology; D010084:Oxidation-Reduction; D009195:Peroxidase / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry; D015203:Reproducibility of Results
D010936:Plant Extracts; D006861:Hydrogen Peroxide; D009195:Peroxidase; D004298:Dopamine