Nuclear chemistry

Reproducibility

Adsorption

Nanoparticle

Carbon paste electrode

Electrochemistry

Materials science

Chromatography

Cyclic voltammetry

Voltammetry

Solid phase extraction

Supporting electrolyte

Biochemistry

Inorganic chemistry

Buffer solution

Cysteine

Physical chemistry

Extraction (chemistry)

Nanotechnology

Organic chemistry

Linear range

Aqueous solution

Enzyme

Analytical Chemistry (journal)

Chemistry

Electrode

Differential pulse voltammetry

Detection limit

Magnetic nanoparticles

Copper

Microchemical Journal

In the present study, magnetic solid-phase extraction (MSPE) was coupled with voltammetric method by using a magnetic carbon paste electrode (MCPE) to determine Cu(II) in aqueous mediums. For this purpose, L-cysteine functionalized core–shell Fe3O4@Au nanoparticles (Fe3O4@[email protected]L-cysteine) was used as an adsorbent during the extraction step. Following that, the magnetic adsorbent pre-concentrated with Cu(II) was collected on the surface of MCPE for electrochemical detection using differential pulse voltammetry. In the suggested assay, the extraction and determination of copper ions were carried out in a single electrochemical cell. The conditions of extraction and voltammetric determination were explored in detail. Under the optimal conditions (i.e., supporting electrolyte, phosphate buffer; sample pH, 5.0; Fe3O4@[email protected]L-cysteine amount, 10 mg L-1 (100 μL); agitation time, 120 s; reduction potential, −0.4 V; and reduction time, 90 s), the response currents were linear in 2.0 to 400.0 nmol L-1 Cu(II) concentration range. The limit of detection and reproducibility of the established method were calculated to be 0.4 nmol L-1 and 3.4%, respectively. The applicability of the suggested methodology was confirmed by analysis of Cu(II) in different water samples with recoveries of 96.4–103.6% (n = 3).

Application of magnetic nanoparticles modified with L-cysteine for pre-concentration and voltammetric detection of copper(II)