Copper(II)-selective electrode using thiuram disulfide neutral carriers

Pulsed galvanostatic control of ion fluxes across polymeric membrane ion-selective electrodes (ISEs) is an emerging field for potentiometric sensing. Herein we report a novel potentiometric enzyme immunoassay based on currentcontrolled release of an enzyme substrate, which eliminates the addition of marker ions in the sample solution. In this method, the carboxylated poly(vinyl chloride) matrix at the outer layer of the ISE membrane is employed to attach a primary antibody. A sandwich immunoassay with an alkaline phosphatase labeled antibody (ALP-Ab) as the reporter is used for the determination of human IgG (as a model protein). The large difference between the lipophilicity of the substrate ion and that of the product ion allows p-nitrophenyl phosphate to be used as the enzyme substrate for potentiometric immunosensors. After the immunoreactions, the captured ALP-Ab catalyzes the hydrolysis of the substrate ions released at the sample−membrane interface by using the pulsed galvanostatic technique. This process can be potentiometrically determined by measuring the open circuit potential of the ISE. Under optimal conditions, the potential response of the proposed immunosensor is proportional to the concentration of human IgG in the range of 50−1000 ng/mL with a detection limit of 30 ng/mL (3σ). Owing to simplicity and independence of sample volume and sample turbidity, the proposed potentiometric immunoassay offers a viable alternative to those based on optical absorbance.

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“…25 Activity coefficients were calculated according to the Debye−Huckel approximation. 27 2.4. Selectivity Measurements.…”

Section: Methodsmentioning

confidence: 99%

Pulsed Galvanostatic Control of a Polymeric Membrane Ion-Selective Electrode for Potentiometric Immunoassays

Ding

Wang

Qin

2013

ACS Appl. Mater. Interfaces

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“…The EMF values were corrected for the liquid-junction potentials with the Henderson equation. The activity coefficients of ions were calculated from the modified Debye-Hückel equation [31].…”

Section: Apparatusmentioning

confidence: 99%

A simple approach for fabricating solid-contact ion-selective electrodes using nanomaterials as transducers

Liang

Yin

Qin

2015

Analytica Chimica Acta

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A general method for fabricating nanomaterials based solid-contact ISEs is developed. The mixture of an ionic liquid and a nanomaterial is used as intermediate layer.The detection limits of the proposed sensors are in the nanomolar range. The developed electrodes exhibit a good response time and excellent stability. A simple and robust approach for the development of solid-state ion-selective electrodes (ISEs) using nanomaterials as solid contacts is described. The electrodes are fabricated by using the mixture of an ionic liquid (IL) and a nanomaterial as intermediate layer, formed by melting the IL. Tetradodecylammonium tetrakis(4-chlorophenyl)borate (ETH 500) is chosen as an model of IL to provide strong adhesion between the inner glassy carbon electrode and the intermediate layer. Nanomaterials including single-walled carbon nanotubes (SWCNTs) and graphene were used as active ion-to-electron transducers between the glassy carbon electrode and the ionophore-doped ISE membrane. By using the proposed approach, the solid-contact Cu 2+ -and Pb 2+ -selective electrodes based on ETH 500/SWCNTs and ETH 500/ graphene as transducers, respectively, have been fabricated. The proposed electrodes show detection limits in the nanomolar range and exhibit a good response time and excellent stability.

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“…The single-ion activities were calculated by using the modified form of the Debye-Hückel equation. 29 …”

Section: Electrode Preparationmentioning

confidence: 99%

Aluminum(III)‐selective PVC Membrane Electrode Based on Salicylaldehyde Salicyloyl Hydrazone

Liu

Yuan

et al. 2011

J Chinese Chemical Soc

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A highly selective PVC membrane electrode for Al 3+ based on salicylaldehyde salicyloyl hydrazone as a neutral carrier has been prepared and studied. The sensor exhibits a good response for Al 3+ over a linear range of 9.0 × 10 -6 to 1.0 × 10 -1 mol/L, with a Nernstian slope of 20.0 ± 0.2 mV/decade and detection limit of 7.0 × 10 -6 mol/L. Selectivity coefficients determined by the method of separate solution indicate high selectivity for Al 3+ . The response mechanism was discussed in view of UV-Vis spectroscopy technique and the A.C. impedance technique. It was used as an indicator electrode in potentiometric titration of Al 3+ with EDTA and in the determination of Al 3+ in real samples. The electrode has a relatively fast response time, long life time and satisfactory stability.

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Copper(II)-selective electrode using thiuram disulfide neutral carriers

Abstract: The values for the equilibrium constants (K2, K3) were estimated from the relevant Eo values. The simulated voltam-

Cited by 410 publications

References 51 publications

Pulsed Galvanostatic Control of a Polymeric Membrane Ion-Selective Electrode for Potentiometric Immunoassays

Pulsed Galvanostatic Control of a Polymeric Membrane Ion-Selective Electrode for Potentiometric Immunoassays

A simple approach for fabricating solid-contact ion-selective electrodes using nanomaterials as transducers

Aluminum(III)‐selective PVC Membrane Electrode Based on Salicylaldehyde Salicyloyl Hydrazone

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