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Electrochemical characterization of redox polymer for monitoring of adenine was described in this study using poly(vinylferrocenium) (PVF(+)) modified platinum (Pt) electrode. Scanning electron microscope (SEM) was used for the surface characterization. The electrochemical behaviors of polymer modified and adenine immobilized polymer modified electrodes were investigated by using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). In order to obtain more sensitive and improved electrochemical signals, analytical parameters such as the effects of polymeric film thickness, immobilization time of adenine, pH and adenine concentration were examined on the response of the polymer modified electrode. Alternating current (AC) impedance spectroscopy was used for the characterization of polymer modified and adenine immobilized polymer modified electrodes. The effect of possible interferents on the response of the electrode was examined., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Characterization of redox polymer, poly(vinylferrocenium) perchlorate (PVF+ClO4-) coated as a film on Pt electrodes, and the detection of DNA based on the electrochemical behavior of the polymer were described in this study. PVF+ClO4- modified electrodes were prepared by the electrooxidation of poly(vinylferrocene) (PVF), and DNA immobilized polymer modified electrode was then prepared. The characterization of the polymer modified electrodes were performed by scanning tunneling microscopy (STM), Raman spectroscopy and alternating current (AC) impedance. The effects of DNA concentration, pH, and polymer films in various thicknesses based on the electrode response were also investigated. The electrochemical behavior of DNA modified polymer electrode by using double-stranded DNA (dsDNA) or single-stranded DNA (ssDNA) was compared. DNA hybridization was also investigated.

A new surface based on poly(vinylferrocenium) (PVF(+))-modified platinum electrode was developed for determination of Hg(2+) ions in aqueous solutions. The polymer was electrodeposited on platinum electrode by constant potential electrolysis as PVF(+)ClO(4)(-). Cl(-) ions were then attached to the polymer matrix by anion exchange and the modified electrode was dipped into Hg(2+) solution. Hg(2+) was preconcentrated at the polymer matrix by adsorption and also complexation reaction with Cl(-). Detection of Hg(2+) was carried out by differential pulse anodic stripping voltammetry (DPASV) after reduction of Hg(2+). Mercury ions as low as 5 x 10(-10)M could be detected with the prepared electrode and the relative standard deviation was calculated as 6.35% at 1 x 10(-6)M concentration (n=6). Interferences of Ag(+), Pb(2+) and Fe(3+) ions were also studied at two different concentration ratios with respect to Hg(2+). The developed electrode was applied to the determination of Hg(2+) in water samples.

Organic peroxides, t-butyl hydroperoxide, 2-butanone peroxide, cumene hydroperoxide and t-butyl peracetate, were determined by an amperometric enzyme electrode. The enzyme electrode was prepared through electrostatic immobilization of horseradish peroxidase (HRP) in a polyvinylferrocenium (PVF) film. A PVF(+)ClO(4)(-) film was coated on a Pt foil at +0.70 V by electrooxidation of polyvinylferrocene in methylene chloride with 0.1 M tetrabutylammonium perchlorate (TBAP). The enzyme modified electrode PVF(+)HRP(-) was prepared by anion-exchange in a solution of HRP(-) in 0.05 M phosphate buffer at pH 8.5. FTIR spectroscopy was used to identify PVF, PVF(+)ClO(4)(-), and PVF(+)HRP(-). The immobilized amount of the enzyme in the film was determined by UV spectroscopy. The effects of the polymeric film thickness, bulk enzyme concentration used in the immobilization treatment and the temperature on the performance of enzyme electrode were investigated. The inhibitory effect of oxygen was also examined. Linearities, lower detection limits, active life times and sensitivities of the electrode were determined for each peroxide.