The Experts below are selected from a list of 63 Experts worldwide ranked by ideXlab platform
Hamid R Zare - One of the best experts on this subject based on the ideXlab platform.
-
electrocatalytic oxidation of hydrazine at glassy carbon electrode modified with Electrodeposited Film derived from caffeic acid
Electroanalysis, 1999Co-Authors: S M Golabi, Hamid R ZareAbstract:A caffeic acid modified glassy carbon electrode was constructed for the electrocatalytic detection of hydrazine. This modified electrode enabled hydrazine to be catalytically oxidized at a greatly reduced overpotential and in a wide operational pH range (pH 5.0–9.0). The overall number of electrons involved in the catalytic oxidation of hydrazine and the number of electrons involved in the rate determining step are 4 and 1, respectively. The rate constant for the catalytic reaction was evaluated by chronoamperometry, cyclic voltammetry and RDE voltammetry and was found to be around 10–3 cm s–1. Experiments were performed to characterize the electrode as an amperometric sensor for the determination of hydrazine and linear calibration plots were obtained over the range of 0.01 to 2.0 mM for linear sweep voltammetry and chronoamperometry. Amperometry in stirred solution exhibits a linear dynamic range of 2.5 μM to 1.0 mM (correlation coefficient 0.9993) and a detection limit of 0.4 M. The resulting modified electrode retains its initial response for at least 2 weeks if stored in phosphate buffer (pH 4). The precision of amperometry was found to be 1.8 % for replicate determinations of a 1.0 mM solution of hydrazine (n=12).
Liping Lu - One of the best experts on this subject based on the ideXlab platform.
-
a selective voltammetric method for uric acid detection at a glassy carbon electrode modified with Electrodeposited Film containing dna and pt fe iii nanocomposites
Electroanalysis, 2004Co-Authors: Shuqing Wang, Liping LuAbstract:A novel biosensor by electrochemical codeposited Pt-Fe(III) nanocomposites and DNA Film was constructed and applied to the detection of uric acid (UA) in the presence of high concentration of ascorbic acid (AA). Based on its strong catalytic activity toward the oxidation of UA and AA, the modified electrode resolved the overlapping voltammetric response of UA and AA into two well-defined peaks with a large anodic peak difference (ΔEpa) of about 380mV. The catalytic peak current obtained from differential pulse voltammetry (DPV) was linearly dependent on the UA concentration from 3.8×10−6 to 1.6×10−4 M (r=0.9967) with coexistence of 5.0×10−4 M AA. The detection limit was 1.8×10−6 M (S/N=3) and the presence of 20 times higher concentration of AA did not interfere with the determination. The modified electrode shows good sensitivity, selectivity and stability.
S M Golabi - One of the best experts on this subject based on the ideXlab platform.
-
electrocatalytic oxidation of hydrazine at glassy carbon electrode modified with Electrodeposited Film derived from caffeic acid
Electroanalysis, 1999Co-Authors: S M Golabi, Hamid R ZareAbstract:A caffeic acid modified glassy carbon electrode was constructed for the electrocatalytic detection of hydrazine. This modified electrode enabled hydrazine to be catalytically oxidized at a greatly reduced overpotential and in a wide operational pH range (pH 5.0–9.0). The overall number of electrons involved in the catalytic oxidation of hydrazine and the number of electrons involved in the rate determining step are 4 and 1, respectively. The rate constant for the catalytic reaction was evaluated by chronoamperometry, cyclic voltammetry and RDE voltammetry and was found to be around 10–3 cm s–1. Experiments were performed to characterize the electrode as an amperometric sensor for the determination of hydrazine and linear calibration plots were obtained over the range of 0.01 to 2.0 mM for linear sweep voltammetry and chronoamperometry. Amperometry in stirred solution exhibits a linear dynamic range of 2.5 μM to 1.0 mM (correlation coefficient 0.9993) and a detection limit of 0.4 M. The resulting modified electrode retains its initial response for at least 2 weeks if stored in phosphate buffer (pH 4). The precision of amperometry was found to be 1.8 % for replicate determinations of a 1.0 mM solution of hydrazine (n=12).
Shuqing Wang - One of the best experts on this subject based on the ideXlab platform.
-
a selective voltammetric method for uric acid detection at a glassy carbon electrode modified with Electrodeposited Film containing dna and pt fe iii nanocomposites
Electroanalysis, 2004Co-Authors: Shuqing Wang, Liping LuAbstract:A novel biosensor by electrochemical codeposited Pt-Fe(III) nanocomposites and DNA Film was constructed and applied to the detection of uric acid (UA) in the presence of high concentration of ascorbic acid (AA). Based on its strong catalytic activity toward the oxidation of UA and AA, the modified electrode resolved the overlapping voltammetric response of UA and AA into two well-defined peaks with a large anodic peak difference (ΔEpa) of about 380mV. The catalytic peak current obtained from differential pulse voltammetry (DPV) was linearly dependent on the UA concentration from 3.8×10−6 to 1.6×10−4 M (r=0.9967) with coexistence of 5.0×10−4 M AA. The detection limit was 1.8×10−6 M (S/N=3) and the presence of 20 times higher concentration of AA did not interfere with the determination. The modified electrode shows good sensitivity, selectivity and stability.
Christopher Hardacre - One of the best experts on this subject based on the ideXlab platform.
-
Effect of Mass Transport on the Electrochemical Oxidation of Alcohols Over Electrodeposited Film and Carbon-Supported Pt Electrodes
Topics in Catalysis, 2018Co-Authors: Vinod Kumar Puthiyapura, Wen-feng Lin, Andrea E. Russell, Dan J. L. Brett, Christopher HardacreAbstract:Electrochemical oxidation of four different alcohol molecules (methanol, ethanol, n -butanol and 2-butanol) at Electrodeposited Pt Film and carbon-supported Pt catalyst Film electrodes, as well as the effect of mass transport on the oxidation reaction, has been studied systematically using the rotating disk electrode (RDE) technique. It was shown that oxidation current decreased with an increase in the rotation rate (ω) for all alcohols studied over Electrodeposited Pt Film electrodes. In contrast, the oxidation current was found to increase with an increase in the ω for Pt/C in ethanol and n -butanol-containing solutions. The decrease was found to be nearly reversible for ethanol and n -butanol at the Electrodeposited Pt Film electrode ruling out the possibility of intermediate CO_ads poisoning being the sole cause of the decrease and was attributed to the formation of soluble intermediate species which diffuse away from the electrode at higher ω. In contrast, an increase in the current with an increase in ω for the carbon supported catalyst may suggest that the increase in residence time of the soluble species within the catalyst layer, results in further oxidation of these species. Furthermore, the reversibility of the peak current on decreasing the ω could indicate that the surface state has not significantly changed due to the sluggish reaction kinetics of ethanol and n -butanol.