Article

Detection of nitrite using poly(3,4-ethylenedioxythiophene) modified SPCEs

Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan; Institute of Polymer Science and Engineering, National Taiwan University, Taipei 10617, Taiwan
Sensors and Actuators B: Chemical 01/2009; DOI: 10.1016/j.snb.2009.04.047

ABSTRACT The poly(3,4-ethylenedioxythiophene) (PEDOT)- and PEDOT/multi-wall carbon nanotubes- (PEDOT/MWCNTs) modified screen-printed carbon electrodes (SPCEs) were fabricated and their catalytic properties towards nitrite were studied. Due to the electrostatic interaction between the negatively-charged nitrite ions and the positively-charged PEDOT film, the operating potential for nitrite oxidation was shifted about 160 mV to negative side, compared to bare SPCE, as a PEDOT film was deposited on the SPCE. The diffusion coefficient obtained from RDE experiment is 2.05×10−5 cm2 s−1. The electron transfer coefficient (α) was increased from 0.515 to 0.615 as the sensing electrode was changed from PEDOT-modified to PEDOT/MWCNTs-modified electrode. Therefore, PEDOT/MWCNTs composite shows the superior catalytic property towards nitrite and the operating potential was further shifted about 100 mV to the negative side. The sensitivity and limit of detection (LOD) for the PEDOT- and PEDOT/MWCNTs-modified SPCEs are about 100 mA cm−2 M−1, 1.72 μM and 140 mA cm−2 M−1, 0.96 μM, respectively. The possible interferences from several common ions were tested. The developed sensor was also applied to the determination of nitrite concentration in tap water sample.

1 Bookmark
 · 
153 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Poly(3,4-ethylenedioxythiophene)-Pt nanoparticle composite was synthesized in one-pot fashion using a photo-assisted chemical method, and its electrocatalytic properties toward hydrogen peroxide (H2O2) was investigated. Under UV irradiation, the rates of the oxidative polymerization of EDOT monomer along with the reduction of Pt4+ ions were accelerated. In addition, the morphology of PtNPs was also greatly influenced by the UV irradiation; the size of PtNPs was reduced under UV irradiation, which can be attributed to the faster nucleation rate. The immobilized PtNPs showed excellent electrocatalytic activities towards the electroreduction of hydrogen peroxide. The resultant amperometric sensor showed enhanced sensitivity for the detection of H2O2 as compared to that without PtNPs, i.e., only with a layer of PEDOT. Amperometric determination of H2O2 at -0.55 V gave a limit of detection of 1.6 μM (S / N = 3) and a sensitivity of 19.29 mA cm-2 M-1 up to 6 mM, with a response time (steady state, t95) of 30 to 40 s. Energy dispersive X-ray analysis, transmission electron microscopic image, cyclic voltammetry (CV), and scanning electron microscopic images were utilized to characterize the modified electrode. Sensing properties of the modified electrode were studied both by CV and amperometric analysis.
    Nanoscale Research Letters 06/2012; 7(1):319. · 2.52 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We have investigated the oxidative electrochemistry of nitrite on glassy carbon electrodes modified with cobalt nanoparticles, poly(3,4-ethylenedioxythiophene) (PEDOT), and graphene. The modified electrode was characterized by cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy. The results suggest that this new type of electrode combines the advantages of PEDOT-graphene films and cobalt nanoparticles and exhibits excellent electrocatalytic activity towards the oxidation of nitrite. There is a linear relationship between the peak current and the nitrite concentration in the range from 0.5 mu M to 240 mu M, and the detection limit is 0.15 mu M. The modified electrodes also enable the determination of nitrite at low potentials where the noise level and interferences by other electro-oxidizable compounds are weak.
    Microchimica Acta 01/2012; 177(3-4):411-418. · 3.43 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this topical review, progress achieved in amperometric sensing of different analytes over conducting polymer-based hybrid electrocatalysts is summarized. We report a variety of synthetic methods and the resulting hybrid assemblies, with the effectiveness of such strategies, for designing conjugated polymer-based hybrids as robust sensors for amperometric detection. Beyond incorporation of metal nanoparticles, metal-oxide and non-oxide semiconductors, carbon-based nanomaterials (nanotubes, graphene, and graphene oxide), and special dopant ions are also discussed. Moreover, some particularly interesting miscellaneous approaches, for example photo-amperometric sensing or use of overoxidized polymers, are also emphasized. Determination of dissolved gases (for example O(2), NO, and NO(2)), ions (sulfite, nitrite, nitrate, chlorate, bromate, and iodate) and smaller and larger molecules (for example H(2)O(2), ascorbic acid (AA), dopamine (DA), urea (UA), amino acids, hydrazine, NADH, serotonin, and epinephrine) is discussed. These achievements are reviewed from the materials perspective, addressing both synthetic and electrocatalytic aspects of the polymer-based modified electrodes. Beyond simple or more sophisticated mixing, a wide range of methods of preparation is presented, including chemical (one-pot polymerization, impregnation), electrochemical (co-deposition, doping type inclusion, etc.) and combined strategies. Classification of such synthetic routes is also included. However, it is important to note that we omit studies in which conducting polymers alone were used for determination of different species. Furthermore, because excellent reviews-cited in this work also-are available on immobilization of biomolecules (for example enzymes) for biosensing purposes, this topic, also, is excluded.
    Analytical and Bioanalytical Chemistry 01/2013; · 3.66 Impact Factor

Full-text (2 Sources)

View
27 Downloads
Available from
May 16, 2014