RESUMO
A glucose biosensor was fabricated with loading of glucose oxidase (GOx) into a new organic-inorganic hybrid nanocomposite. The preparation involves formation of silica network into a Nafion (perfluorosulfonate ionomer) and subsequent loading of polyaniline grafted multiwalled carbon nanotubes (MWNT-g-PANI) onto Nafion-silica nanocomposite. Field emission scanning electron microscopy (FE-SEM) of Nafion-silica/MWNT-g-PANI composite reveals the presence of spherical silica particles (sizes in the range 250 nm-1 microm) and tubular MWNT-g-PANI particles. Chronoamperometry and cyclic voltammetry were used to evaluate the performance of biosensor towards glucose. The Nafion-silica/MWCNT-g-PANI/GOx biosensor exhibited a linear response to glucose in the concentration range of 1-10 mm with a correlation coefficient of 0.9972, good sensitivity (5.01 microA/mm), a low response time (approximately 6s), repeatability (R.S.D value of 2.2%) and along-term stability. The presence of silica network within Nafion and MWNT-g-PANI synergistically contributes to the performance of the biosensor towards the electrochemical detection of glucose.
Assuntos
Resinas Acrílicas , Compostos de Anilina/química , Técnicas Biossensoriais , Eletroquímica/métodos , Polímeros de Fluorcarboneto/química , Glucose/química , Nanocompostos/química , Nanotubos de Carbono/química , Dióxido de Silício/química , Relação Dose-Resposta a Droga , Enzimas Imobilizadas/química , Glucose Oxidase/química , Humanos , Microscopia Eletrônica de Varredura/métodos , Reprodutibilidade dos TestesRESUMO
Structurally related phenyl alcohols were separated by capillary electrophoresis and liquid chromatography. A statistical experimental design was used in order to optimize the main electrophoretic parameters such as pH, concentration of selector and separation voltage in capillary electrophoresis (CE). Response surfaces were derived using the mathematical model and used for a selection of the optimal experimental conditions. Concentration of the chiral selector, the distance between the aromatic group and asymmetric center of the analytes, were identified as the factors influencing the complexation, selectivity and resolution. Experiments were also performed by high-performance liquid chromatography (HPLC) and the results of CE and HPLC were compared.
