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ABSTRACT: Electrochemical detection of p-nitrophenol (P-NP) using a highly sensitive and selective platform based on single-walled carbon nanotube/pyrenecyclodextrin (SWCNT/PyCD) nanohybrids is described for the first time. The electrochemical performance of the SWCNT/PyCD nanohybrid electrode was fully compared with bare glassy carbon, single-SWCNT, single-PyCD, and SWCNT/CD (without pyrene rings) electrodes. Besides the techniques of cyclic voltammetry and chronoamperometric transients, differential pulse voltammetry (DPV) has been used for the detection of P-NP without any interference from o-nitrophenol (O-NP) at the potentials of -0.80 and -0.67 V, respectively. The SWCNT/PyCD nanohybrid electrode is highly sensitive, and it shows an ultrahigh sensitivity of 18.7 μA/μM toward P-NP in contrast to the values reported previously. The detection limit (S/N = 3) of the SWCNT/PyCD nanohybrid electrode toward P-NP is 0.00086 μM (0.12 ppb), which is well below the allowed limit in drinking water, 0.43 μM, given by the U.S. Environmental Protection Agency (EPA). The analytical performance of the SWCNT/PyCD nanohybrid electrode toward P-NP is superior to the existing electrodes.
Langmuir 08/2011; 27(16):10295-301. · 4.19 Impact Factor
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Journal of Raman Spectroscopy 03/2011; 42(9):1728 - 1735. · 3.09 Impact Factor
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ABSTRACT: This work reports the first detailed study on an electrochemical impedance sensor for determination of polychlorinated biphenyl (PCB), such as 3,3',4,4'-tetrachlorobiphenyl (PCB-77), based on a single-walled carbon nanotube/pyrenecyclodextrin (SWCNT/PyCD) hybrid.
Chemical Communications 03/2011; 47(18):5340-2. · 6.17 Impact Factor
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ABSTRACT: This work reports a surface ion imprinting strategy in electropolymerized microporous poly(2-mercaptobenzothiazole) (MPMBT) films at the surface of glassy carbon electrode (GCE) for the electrochemical detection of Hg(II). The Hg(II)-imprinted MPMBT/GCE exhibits larger binding to functionalized capacity, faster binding kinetics and higher selectivity to template Hg(II) due to their high ratio of surface-imprinted sites, larger surface-to-volume ratios, the complete removal of Hg(II) templates and larger affinity to Hg(II). The square wave anodic stripping voltammetry (SW ASV) response of the Hg(II)-imprinted MPMBT/GCE to Hg(II) is ca. 3.0 and 5.9 times larger than that at the direct imprinted poly(2-mercaptobenzothiazole) modified GCE and non-imprinted MPMBT/GCE sensor, respectively; and the detection limit for Hg(II) is 0.1nM (which is well below the guideline value given by the World Health Organization). Excellent wide linear range (1.0-160.0nM) and good repeatability (relative standard deviation of 2.5%) were obtained for Hg(II). The interference experiments showed that mercury signal was not interfered in the presence of Pb(II), Cd(II), Zn(II), Cu(II) and Ag(I), respectively. These values, particularly the high sensitivity and excellent selectivity compared favorably with previously reported methods in the area of electrochemical Hg(II) detection, demonstrate the feasibility of using the prepared Hg(II)-imprinted MPMBT/GCE for efficient determination of Hg(II) in aqueous environmental samples.
Analytica chimica acta 01/2011; 685(1):21-8. · 4.31 Impact Factor
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ABSTRACT: Three-dimensional (3D) gold micro-/nanopore arrays containing 2-mercaptobenzothiazole (MBT) adapters have been prepared and employed to improve the performance of the determination of trace mercury in solution using square wave anodic stripping voltammetry (SWASV). 3D gold micro-/nanopore arrays have an active surface area which is up to 4 and 15 times higher than a two-dimensional (2D) bowl-like structured microarrays and a flat solid gold electrode characterized by cyclic voltammetry, respectively. In this study, 3D MBT molecular adapters on the array surface greatly decreased the effect of capacitive current and enhanced the sensitivity and selectivity of the electrode. A limit of detection of 0.02 nM (which is well below the guideline given by the World Health Organization) and more importantly, a sensitivity of 1.85 μA nM−1 was obtained using this system. Furthermore, excellent linear range (0.05–10 nM) and good repeatability (relative standard deviation of 2.10%) were obtained for Hg(II). Interference experiments were also investigated, and it was determined that Pb(II), Cd(II), Zn(II), Cu(II) and Ag(I) had little or no influence on the mercury signal.
Electrochimica Acta. 56(1):463-469.
