Browsing by Author "Gutierrez, Cesar"

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    MODIFICATION OF BORON DOPED DIAMOND ELECTRODES WITH GLUCOSE OXIDASE, CHARACTERIZATION BY ELECTROCHEMICAL TECHNIQUES
    (SOC CHILENA QUIMICA, 2011) Del Rio, Rodrigo; Armijo, Francisco; Schrebler, Ricardo; Del Canto, Gabriela; Vergara, Claudia; Gutierrez, Cesar
    In this work, we report the effect of the direct successive modifications with Glucose oxidase onto boron doped diamond electrode (BDD). The modification due to the enzyme adsorption, on the potentiodynamic response of the electrode, was evaluated using Fe(CN)(6)(4-/3-) red-ox couple on the electrolyte and the Delta Ep variations were related with the number of modifications. Contact angle measurements and the electrochemical impedance spectra were also used to characterized the modifications and they showed variations in the same way that the potentiodynamic data.
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    Modification of composites of block copolymers-gold nanoparticles with enzymes and their characterization by electrochemical techniques
    (SPRINGER, 2011) Del Rio, Rodrigo; Armijo, Francisco; Schrebler, Ricardo; Gutierrez, Cesar; Amaro, Andrea; Biaggio, Sonia R.
    In this work, the poly(styrene-vynil pyridine) block copolymer was used as a porous pattern to study the electrodeposition of gold inside the pores, as a new method to obtain gold nanoparticles. The porous pattern left by the copolymer film onto a conductive glass surface was characterized by atomic force microscopy (AFM), evidencing pores of 30 nm diameter. After the electrodeposition, 30 nm diameter gold nanoparticles were obtained and they were characterized by cyclic voltammetry (CV) and AFM, and then used to study the adsorption of glucose oxidase enzyme. The adsorption process of glucose oxidase on gold nanowires was investigated by CV and electrochemical impedance spectroscopy. The morphological and capacitance results indicate that the block copolymer-gold nanoparticle composite seems to be a good candidate to design biosensors and immunosensors.