Polarographic oxidation and reduction of p-nitroaniline at carbon paste electrodes

Olson, Carl R.; Lee, H.Y.; Adams, Ralph N.

doi:10.1016/0022-0728(61)85020-1

Cited by 9 publications

(5 citation statements)

References 4 publications

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“…p NA displayed an oxidation peak at 1.1 V vs Ag/AgCl and a reduction peak at −0.80 vs Ag/AgCl. This oxidation peak represents oxidation of the amino group of p NA, whereas the reduction peak of pNA represents a reduction in the nitro group of p NA . The reduction current of p NA is larger than the oxidation current of the pNA because of the difference in the number of transferred electrons.…”

Section: Resultsmentioning

confidence: 99%

“…This oxidation peak represents oxidation of the amino group of pNA, 18 whereas the reduction peak of pNA represents a reduction in the nitro group of pNA. 19 The reduction current of pNA is larger than the oxidation current of the pNA because of the difference in the number of transferred electrons. Therefore, we decided to perform an immunoassay to detect the reduction current of pNA.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

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Highly Sensitive Electrochemical Immunoassay Using Signal Amplification of the Coagulation Cascade

et al. 2022

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Here, we report a highly sensitive immunoassay for human immunoglobulin G (IgG) that uses signal amplification of the coagulation cascade. Z-Phe-Pro-Lys-p-nitroaniline (FPK-pNA) was used as a substrate for thrombin activation in the last step of the coagulation cascade. During the coagulation cascade, pNA is liberated from FPK-pNA and can be detected electrochemically. Using square wave voltammetry with a glassy carbon electrode, we demonstrated that pNA can be quantified in a solution modeling the coagulation cascade prepared by mixing FPK-pNA and pNA. Characterization of the reactivity of thrombin toward FPK-pNA revealed that thrombin efficiently reacted with FPK-pNA. Subsequent characterization of factor XIa activity of factor XIalabeled antibody revealed that factor XIa was not inactivated during labeling. Finally, a coagulation cascade-based immunoassay for human IgG was performed using a factor XIa-labeled antibody on magnetic beads. The limit of detection for human IgG was 5.0 pg/mL (33 fM) indicating that the coagulation cascade can amplify the immunoassay sensitivity compared to immunoassay using a thrombin-labeled antibody as a condition without a coagulation cascade. Coagulation cascade-based immunoassay was also highly selective. In the near future, we will report a highly sensitive immunoassay for the simultaneous detection of multiple analytes using a coagulation cascade-based immunoassay and Limulus amebocyte lysate reaction-based immunoassay we previously reported.

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Section: Resultsmentioning

confidence: 99%

Section: ■ Results and Discussionmentioning

confidence: 99%

Highly Sensitive Electrochemical Immunoassay Using Signal Amplification of the Coagulation Cascade

et al. 2022

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“…In the early 1960s, Olson and co-authors [64] studied the electrochemical behavior of p-nitroaniline on the surface of a carbon paste electrode. They established that reduction of the -NO 2 groups involves 6e À and can form amine products [64,65]. In the work of Tong et al [66], the authors used a rotating disk electrode to study the PPD reactions at the electrode.…”

Section: Electroanalysis Of Hair Dyesmentioning

confidence: 99%

Advances and Trends in Voltammetric Analysis of Dyes

Hudari¹,

Brugnera²,

Zanoni³

2017

Applications of the Voltammetry

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Since 1856 when W. H. Perkin synthesized the first synthetic dye (Mauveine), a wide variety of colors and shades are produced and used in several commercial products. The occurrence in water and wastewater has gained controversy regarding their toxicity and mutagenicity and it has been regulation by several regulatory agencies. Thus, analytical methods able to determine these colorings in several matrices with high sensitive and robust enough are relevant. Among several analytical methods, the use of electroanalytical methods, especially the voltammetric techniques, are of great interest due to the high selectivity, sensitivity, use of low quantity of sample, little or without sample treatment, and low waste generation, which contributes to reduced environmental impact. Over the past decades, the technical based on current-potential curves by using of static electrodes have gained considerable progress, as minimizing the effect of capacitive current and the possibility of pre-concentration of the analyte at the electrode surface, which has reflected in lower detection levels. The present work gives an overview about the analytical methods available in literature focusing on electroanalysis of dyes by using voltammetric techniques. The advances of the electroanalytical techniques and the use of different modifiers to increase sensitivity and selectivity are reviewed.

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“…The first wave, as in acetonitrile, involves one electron and forms an anion radical. The second wave corresponds to a three-electron reduction (441,442)• The anion radical has been detected spectrophotometrically and is oxidized anodically to nitrobenzene (448, 444)• The effect of various supporting electrolytes on the reduction of pand m-substituted nitrobenzenes in acetonitrile and dimethylformamide is reported (824) Studies are reported for the reduction of p-chloronitrobenzene and p-nitrotoluene at a rotating solid disk electrode (329), nitrobenzene and 3,5-dinitrobenzoic acid at a platinum electrode covered with a mercury film (651), oxidation and reduction of p-nitroaniline at a carbon paste electrode (724), and reduction of the isomeric nitrohalobenzenes at a hanging mercury drop electrode (464). EPR studies of the first stage reduction product from onitrobromobenzene point to an elimination reaction since the spectrum of the nitrobenzene anion radical was obtained (464)• Chronopotentiometric measurements are reported for nitrobenzene (301) and for p-dinitrobenzene (437, 502), and oscillopolarographic studies are reported for nitrobenzene (311), 1chloro -3,4 -dinitronaphthalene (672), nitrobenzene, o-nitrophenol and p-nitrophenol (347).…”

Section: R-i + E -» [R-i ]mentioning

confidence: 99%