A novel lactose biosensor based on electrochemically synthesized 3,4-ethylenedioxythiophene/thiophene (EDOT/Th) copolymer

In this study, a new lactose biosensor has been developed in which the 3,4-ethylenedioxythiophene/thiophene (EDOT/Th) copolymer is used as a transducer. The EDOT/Th copolymer was deposited on the glassy carbon electrode to be used as the working electrode. In addition to the working electrode, the three-electrode system was used in both the electrochemical synthesis and in the biosensor measurements. Lactase (β-galactosidase) that catalyzes the breakdown of lactose into monosaccharides (glucose and galactose) and galactose oxidase that catalyzes the oxidation of the resulting galactose were attached to the copolymer by a cross-linker on the modified working electrode. The response of the enzyme electrode to lactose was determined by cyclic voltammetry (CV) at +0.12 V. Enzyme electrode optimization parameters (pH, temperature, enzyme concentration, etc.) were performed. Fourier transform infrared spectroscopy, scanning electron microscopy and CV methods were used to support copolymer formation. In addition, the characteristics of the enzyme electrode prepared in this study (Km, 0.02 mM; activation energy Ea, 38 kJ/mol; linear working range, up to 1.72 mM; limit of detection, 1.9 × 10−5 M and effects of interferents [uric acid and ascorbic acid]) were determined

Polyfuran-based multi-walled carbon nanotubes and graphene nanocomposites as counter electrodes for dye-sensitized solar cells

WOS: 000429485300024The preparation of polyfuran-graphene (PFu/GR) and polyfuran-multi-walled carbon nanotube (PFu/MWCNT) nanocomposites was carried out via a plasma polymerization. The characterizations of the pure GR, MWCNTs and the nanocomposites coated with PFu were performed using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy analyses. Counter electrodes prepared using the nanocomposites were used in dye-sensitized solar cells (DSSCs), demonstrating an enhancement in cell performance. The maximum efficiency of the DSSC with the PFu/GR counter-electrode with a short-circuit photocurrent density of 32.26 mA/cm(2) was 5.06%, which is much higher than that of the short-circuit photocurrent density of 14.11 mA/cm(2) and efficiency of 2.13% in the cell using the GR counter electrode. This was attributed to the enhanced conductivity between the PFu-based counter electrode and the electrolyte.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [114M867]; bilateral Project SAS-TUBITAK JRP; VEGA 02/0149/14This work was supported by The Scientific and Technological Research Council of Turkey (TUBITAK; Project No. 114M867) and by the bilateral Project SAS-TUBITAK JRP 2014/2. Work was partially supported by the Project VEGA 02/0149/14 (Slovakia). Sule Erten-Ela acknowledges the Alexander von Humboldt foundation and Turkish Academy of Sciences (TUBA)