Voltammetric detection of carbofuran determination using screen-printed carbon electrodes modified with gold nanoparticles and graphene oxide.

Carbofuran is a highly toxic pesticide that is heavily used in agriculture due to its high effectiveness and low cost. Improved methods that are simpler and lower cost are needed for carbofuran detection in food and agricultural samples. Herein, we describe the development of a unique electrochemical method for carbofuran-phenol, which is the main hydrolysis product of carbofuran.

Determination of nickel(II) by ion-transfer to hydroxide medium using sequential injection-electrochemical analysis (SIECA).

A method for the determination of Ni(II) using ion-transfer to a hydroxide medium has been developed by the sequential injection-electrochemical analysis (SIECA), a combination between an automated flow-based analysis and electrochemical techniques with a homemade screen-printed carbon electrode (SPCE). A sample/standard solution was introduced into an electrochemical flow cell where the Ni(II) in the solution was electrochemically reduced and accumulated on the SPCE. The accumulated Ni was then oxidized to Ni(II) in a hydroxide medium, which led to the formation of nickel hydroxide (Ni(OH)) and nickel oxyhydroxide (NiOOH) on the SPCE.

Polyaniline/graphene quantum dot-modified screen-printed carbon electrode for the rapid determination of Cr(VI) using stopped-flow analysis coupled with voltammetric technique.

Polyaniline/graphene quantum dots (PANI/GQDs) were used to modify a screen-printed carbon electrode (SPCE) in a flow-based system. A method for rapidly determining the Cr(VI) concentrations by using stopped-flow analysis has been developed using an Auto-Pret system coupled with linear-sweep voltammetry using the PANI/GQD-modified SPCE. The GQDs, synthesized in a botton-up manner from citric acid, were mixed with aniline monomer in an optimized ratio.

Graphene/polyvinylpyrrolidone/polyaniline nanocomposite-modified electrode for simultaneous determination of parabens by high performance liquid chromatography.

A nanocomposite of graphene (G), polyvinylpyrrolidone (PVP) and polyaniline (PANI) modified onto screen-printed carbon electrode (SPCE) using an electrospraying technique was developed for simultaneous determination of five parabens in beverages and cosmetic products by high performance liquid chromatography. PVP and PANI were used as the dispersing agents of graphene, and also for the enhancement of electrochemical conductivity of the electrode. The electrochemical behavior of each paraben was investigated using the G/PVP/PANI nanocomposite-modified SPCE, compared to the unmodified SPCE.

Method development for the determination of arsenic by sequential injection/anodic stripping voltammetry using long-lasting gold-modified screen-printed carbon electrode.

An automated method has been developed for determining the concentration of inorganic arsenic. The technique uses sequential injection/anodic stripping voltammetry with a long-lasting gold-modified screen-printed carbon electrode. The long-lasting gold electrode was electrochemically deposited onto a screen-printed carbon electrode at a potential of -0.

Graphene-carbon paste electrode for cadmium and lead ion monitoring in a flow-based system.

An environment friendly electrode for determining Cd(2+) and Pb(2+) levels in an automated flow system was successfully developed. Cyclic voltammetry and square wave anodic stripping voltammetry (SWASV) coupled with sequential injection analysis (SIA) were employed to study the electrochemical behavior of the electrode. The in situ bismuth-modified graphene-carbon paste electrode (Bi-GCPE) exhibited excellent electrooxidation of Cd(2+) and Pb(2+) in the automated flow system with a significantly higher peak current for both metal ions compared with the unmodified CPE.