Ion-exchange voltammetry at a surfactant-doped electrode: model of mass transfer kinetics to an anionic surface-charged electrode and its application for the sensitive determination of alkaline phosphatase

cited By 10; International audience; A theoretical model of mass transfer kinetics was developed for investigating the accumulation of cationic compounds at an anionic surfactant-doped screen-printed electrode. It was extended to an enzyme-generated cationic product for the indirect determination of alkaline phosphatase (AP). The model takes into account the analyte depletion, the kinetics of the ion-exchange reaction-diffusion and the kinetics of the enzymatic reaction. The relationship between the ion-exchange voltammetric anodic peak current and the enzyme incubation/accumulation time for a given concentration of AP was established and the validity of the theoretical model was verified e…

Enzyme Affinity Assays Involving a Single-Use Electrochemical Sensor. Applications to the Enzyme Immunoassay of Human Chorionic Gonadotropin Hormone and Nucleic Acid Hybridization of Human Cytomegalovirus DNA

Simultaneous homogeneous immunoassay of phenytoin and phenobarbital using a Nafion-loaded carbon paste electrode and two redox cationic labels

Abstract The dual-analyte homogeneous immunoassay of two antiepileptic drugs was carried out simultaneously at physiological pH by square-wave voltammetry at a Nafion-loaded carbon paste electrode. Phenobarbital (PB) and phenytoin (DPH) were labeled by a cobaltocenium salt (Cc+) and a ferroceneammonium salt (N+Fc), respectively, and the corresponding standard redox potentials were −1.05 V and 0.26 V. Detection limits of 0.25 and 0.2 μM were achieved for PB-Cc+ and DPH-N+Fc (S/N = 3) after a 5-minute accumulation step, with linear responses over the 0.25–5 and 0.2–5 μM ranges, respectively. The relative standard deviation was evaluated to be ≥ 11% for 1 μM of each labeled drug. The separate,…