Article

A 3D-impedimetric immunosensor based on foam Ni for detection of sulfate-reducing bacteria

Graduate School of the Chinese Academy of Sciences, 19 (Jia) Yuquan Road, Beijing 100039, China
Electrochemistry Communications (Impact Factor: 4.29). 02/2010; 12(2):288-291. DOI: 10.1016/j.elecom.2009.12.017

ABSTRACT A 3D-immunosensor based on simple and efficient trapping platform (foam Ni) combining with adsorption of gold nanoparticles and specific recognition of biological/chemical molecular has been reported for detection of sulfate-reducing bacteria (SRB) using electrochemical impedance spectroscopy (EIS). The impedance spectra were also used to characterize the successful construct and stepwise modification of the impedimetric immunosensors. This results show that a linear relationship between electron-transfer resistance (Rct) values and the logarithm of the SRB concentrations was obtained for the SRB concentration range of 2.1 × 101–2.1 × 107 cfu/ml. Additionally, the fabricated immunosensor shows a high selectivity against other bacteria.

0 Followers
 · 
91 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: A facile, sensitive and reliable impedimetric immunosensor doped with reduced graphene sheets (RGSs) and combined with a controllable electrodeposition technique was developed for the selective detection of marine pathogenic sulphate-reducing bacteria (SRB). The morphology of RGSs and the electrochemical properties of RGSs-doped chitosan (CS) nanocomposite film were investigated by atomic force microscopy, Fourier transform infrared spectroscopy, and cyclic voltammetry (CV). Electrochemical impedance spectroscopy and CV were used to verify the stepwise assembly of the sensor system. Faradic impedance spectroscopy for charge transfer for the redox probe Fe(CN)(6)(3-/4-) was done to determine SRB concentrations. The diameter of the Nyquist diagram that is equal to the charge-transfer resistance (R(ct)) increased with increasing SRB concentration. A linear relationship between R(ct) and SRB concentration was obtained in the SRB concentration range of 1.8×10(1) to 1.8×10(7) cfu/ml. The impedimetric biosensor gave a distinct response to SRB, but had no obvious response to Vibrio angillarum. It showed a high selectivity for the detection of the pathogen. Based on a combination of the biocompatibility of CS and good electrical conductivity of RGSs, a nanocomposite film with novel architecture was used to immobilize biological and chemical targets and to develop a new type of biosensor.
    Biosensors & Bioelectronics 08/2010; 26(5):1959-64. DOI:10.1016/j.bios.2010.08.008 · 6.45 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Mouse anti-human integrin β1 monoclonal antibody was assembled on glass carbon electrode by layer-by-layer adsorption. The determination of cervical cancer HeLa cells was performed using electrochemical impedance spectroscopy based on the immunoreaction between integrin β1 on cell membrane and the antibody immobilized on the electrode-surface. The factors influencing cell-detection, such as the concentration of gold nanoparticles in the modified film, the drying time of the modified film, the concentration of antibody and the binding time of antibody, were investigated, respectively. Under optimum conditions, the increasing extent of electrode-transfer resistance depended linearly on the cell concentration in the range of 1.0 × 104 to 2.0 × 106 cells mL−1 with a detection limit of 3.5 × 103 cells mL−1.
    Sensors and Actuators B Chemical 08/2010; 149(1-149):87-93. DOI:10.1016/j.snb.2010.06.026 · 3.84 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A fast, sensitive and reliable potentiometric stripping analysis (PSA) is described for the selective detection of the marine pathogenic sulfate-reducing bacterium (SRB), Desulforibrio caledoiensis. The chemical and electrochemical parameters that exert influence on the deposition and stripping of lead ion, such as deposition potential, deposition time and pH value were carefully studied. The concentration of SRB was determined in acetate buffer solution (pH 5.2) under the optimized condition (deposition potential of -1.3V, deposition time of 250s, ionic strength of 0.2 mol L(-1) and oxidant mercury (II) concentration of 40 mg L(-1)). A linear relationship between the stripping response and the logarithm of the bacterial concentration was observed in the range of 2.3 x 10 to 2.3 x 10(7) cfu mL(-1). In addition, the potentiometric stripping technique gave a distinct response to the SRB, but had no obvious response to Escherichia coli. The measurement system has a potential for further applications and provides a facile and sample method for detection of pathogenic bacteria.
    Talanta 09/2010; 82(4):1608-11. DOI:10.1016/j.talanta.2010.07.030 · 3.51 Impact Factor