Search

Dopamine (DA) is biologically important molecule, which plays a vital role in hormonal, renal, cardiovascular, and central nervous systems. Since abnormal level of this biological molecule leads to several diseases, its accurate and fast monitoring is of great importance for clinical diagnosis and treatment. The electrochemical approaches have become of significant interest to fulfill the requirements of DA detection. The electrode modifications play a crucial role in sensitive and selective detection of DA. This review presents the progress of poly(3,4-ethylenedioxythiophene) (PEDOT)-based materials modified electrodes for electrochemical determination of DA in the presence of interferents such as AA and UA. [ABSTRACT FROM AUTHOR]

Poly(3,4-ethylenedioxythiophene) was deposited on a reduced graphene oxide-decorated glassy carbon electrode through an electrochemical polymerization. The resulting glassy carbon electrode-reduced graphene oxide-poly(3,4-ethylenedioxythiophene) electrode was applied as an electrochemical biosensor for the determination of dopamine in the presence of ascorbic acid and uric acid. The material deposited on glassy carbon electrode was investigated in terms of morphology and structural analysis. The comparison of electrochemical behavior of the glassy carbon electrode-reduced graphene oxide-poly(3,4-ethylenedioxythiophene) electrode with the glassy carbon electrode-graphene oxide, glassy carbon electrode-reduced graphene oxide, and glassy carbon electrode-poly(3,4-ethylenedioxythiophene) electrodes exhibited high electrocatalytic activity for dopamine detection. Electrochemical kinetic parameters of glassy carbon electrode-reduced graphene oxide-poly(3,4-ethylenedioxythiophene), including the charge transfer coefficient α (0.49) and electron transfer rate constant ks (1.04), were determined and discussed. The glassy carbon electrode-reduced graphene oxide-poly(3,4-ethylenedioxythiophene) electrode was studied for the determination of dopamine by differential pulse voltammetry and exhibited a linear range from 19.6 to 122.8 µM with a sensitivity of 3.27 µA µM−1 cm−2 and a detection limit of 1.92 µM. The developed biosensor exhibited good selectivity toward dopamine with high reproducibility and stability. [ABSTRACT FROM AUTHOR]

Multiwalled carbon nanotube (MWCNT) was modified through plasma polymerization of aniline by applying different radio frequency (radio frequency (RF): 13.56 MHz) powers. The modified MWCNTs were investigated in terms of morphology, chemical structure, and thermal behaviors, indicating the formation of composites based on the surface modification of MWCNT with polyaniline (PANI). These composites were then used in amperometric glucose biosensor, which was constructed by immobilizing glucose oxidase on premodified Pt electrode with PANI/MWCNT composites. The biosensor based on the composite obtained under RF power of 60 W exhibited the high sensitivity of 54.91 µA mM−1 cm−2 to glucose. [ABSTRACT FROM AUTHOR]

This study presents the preparation of graphene (GR) nanocomposites with polyaniline (PANI) and polypyrrole (PPy) through the fast, versatile and environmentally friendly process of radio frequency (RF)-plasma polymerization. Morphological characterization of the nanocomposites is performed using scanning electron microscopy (SEM) and shows that the PANI and PPy conducting polymers coated the GR surface. The surface properties of the GR nanocomposites are determined using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The prepared GR nanocomposites are then used as counter electrodes in dye-sensitized solar cells (DSSCs). The conversion cell efficiencies for iodine-doped DSSC samples are found to be 0.086%, 5.41%, and 5.60% for I2-PANI, I2-PANI-GR and I2-PPy-GR, respectively, while the corresponding undoped samples reaches power conversion efficiencies of 3.82%, 1.30%, and 0.077% for PPy-GR, PANI-GR and PANI, respectively. The incident photon-to-current efficiency (IPCE) of iodine-doped composite-based DSSCs is significantly enhanced. [ABSTRACT FROM AUTHOR]

Porphyrin sensitizer (Por) containing 4-carboxybiphenyl and 2-thienyl and its metallated Zn(II) derivative (ZnPor) were synthesized and investigated. The porphyrin dyes were characterized by MALDI-MS,1H NMR, UV–vis, fluorescence and cyclic voltammetry methods. It was found that using of biphenyl bridge between anchoring group and porphyrin core enhanced the conjugation length of the porphyrin macrocycle. The new porphyrin dyes were used as sensitizers in dye-sensitized solar cells (DSSCs). ZnPor-based dye sensitized solar cells yielded a short circuit photocurrent density of 3.98 mA cm−2, an open circuit voltage of 500 mV, and a fill factor of 0.67, corresponding to an overall conversion efficiency (η) of 1.33%. [ABSTRACT FROM AUTHOR]

Poly(3,4-ethylenedioxxythiophene) (PEDOT), polyaniline (PANI) and polythiophene (PTh) based multi-walled carbon nanotube (MWCNT) composites were successfully prepared using RF-rotating plasma grafting method. Morphological characterizations of composites were determined using scanning electron microscopy (SEM), which showed that conducting polymers (CPs) of PEDOT, PANI and PTh were coated on the surface of CNTs. The surface properties of the Carbon Nanotube (CNT) composites were also determined by using Infrared Spectra (FT-IR), X-ray Photon Spectra (XPS), and Scanning Electron Microscopy-Energy Dispersive X-ray Spectra (SEM-EDX) analysis. X-ray photon spectra results confirmed the formation of the composites. Composites of MWCNT were used in dye-sensitized solar cells (DSSCs) as counter electrodes and exhibited short-circuit photocurrent densities of 11.19, 10.70 and 8.54 mA/cm2for PANI/MWCNT, PTh/MWCNT and PEDOT/CNT, respectively. [ABSTRACT FROM AUTHOR]