Eletrodo de diamante dopado com boro poroso como sensor eletroquímico para aplicações em análise por injeção em fluxo

Porous boron-doped diamond (p-BDD) electrode was prepared and appliedas an electrochemical amperometric detectorinflow-injection analysis (FIA) system. Porous BDD film was obtained by Hot Filament Chemical Vapor Deposition (HFCVD) over oxygen plasma function alized carbon nanotubes [1]. The analytical performance of the designed p-BDD electrode under FIA conditions was investigated using two model electroactive analytes:epinephrine (EP, an important neurotransmitter) and acetaminophen (AC, a widely consumedanalgesic)[2]. All experimental parameters, such as applied potential, flow-rate and injection volume were optimized. By applying the best working conditions, amperograms were recorded after successive injections of standard solutions containing EP (Fig.1 a) or AC (Fig.1 b) at different concentration levels.The obtained analytical curves were linear from 0.60 to 30.0 μmol L−1(EP) and from 0.80 to 70.0 μmol L−1 (AC), with limits of detection of 0.50 μmol L−1and 0.70 μmol L−1for EP and AC, respectively. Besides that, the electrode did notpresent any adsorption effects, which resultedin an excellent repeatability of amperometric measurement. The applicability of the developed FIA procedure was demonstrated for the AC and EP determination in serum fluidwith satisfactory results and recovery percentages.For the best of our knowledge, this is the first time that a p-BDD electrodeis explored as FIA electrochemical sensor. p-BDD large surface area provided a high sensitivity without the adverse influence of its high capacitance and adsorption.