title: Determination of isoniazid in human urine using screen-printed carbon electrode modified with poly-L-histidine.
abstract: A sensitive voltammetric method for trace measurements of isoniazid (INZ) in synthetic human urine sample is described. The method is based on its electroreduction at -0.98V vs. Ag/AgCl on screen-printed carbon electrode (SPCE) modified with poly-l-histidine (PH). A film of good adherence on SPCE and electrocatalytic properties was obtained coating the electrode by histidine monomer electropolymerization process (SPCE/EPH). The electrochemical behavior of the modified SPCE was investigated by cyclic, linear sweep (LSV), differential pulse (DPV), square-wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS). Limits of detection of 5.0x10(-7) mol L(-1), 1.7x10(-7) mol L(-1) and 2.5x10(-7) mol L(-1) were estimated from LSV, DPV and SWV determinations, respectively. The method was successfully applied to the determination of INZ in human urine samples.
authors.affiliation: Departamento de Química, Centro Politécnico, UFPR, Curitiba, PR, Brazil.
authors.forename: Márcio F
authors.initials: MF
authors.lastname: Bergamini
authors.forename: Daniela P
authors.initials: DP
authors.lastname: Santos
authors.forename: Maria Valnice B
authors.initials: MV
authors.lastname: Zanoni
mesh_terms: D000995:Antitubercular Agents / Q000652:urine*; D002244:Carbon / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D006639:Histidine / Q000737:chemistry*; D006801:Humans; D007538:Isoniazid / Q000652:urine*; D057230:Limit of Detection
chemical_list: D000995:Antitubercular Agents; C033223:polyhistidine; D006639:Histidine; D002244:Carbon; D007538:Isoniazid