Determination of Matrine Using a New Voltammetric Sensor Based on L‐Cysteine/Graphene Oxide‐Chitosan Composite Film Modified Electrode

Abstract

A new voltammetric sensor for matrine was fabricated via the polymerization of l-cysteine on graphene oxide, which served as templates. The fabricated electrode can improve the oxidation of matrine intensively, and enable the determination of matrine in the range from 4 10 À6 to 1 10 À4 mol L À1 , with a detection limit of 2 10 À6 mol L À1. The oxidation process of matrine was studied and some dynamic parameters were calculated using various electrochemical techniques. This present sensor displayed good stability, reproducibility and sensitivity for matrine. It was successfully applied to the quantitative determination of matrine in matrine injection with satisfactory results.

Development of a Novel Electrochemical Sensor for Determination of Matrine in Sophora flavescens

“…It was found that the same electrons and protons are consumed in the electrode reaction as indicated by the slope of the regression equation. Therefore, the oxidation mechanism for matrine can be written as shown in Figure 4 , which is in accordance with the report [ 23 , 66 ]. Besides, the i pa varies very little in the range of 7.0–7.5, so the solution pH of 7.5 was chosen in the following experiments, which is close to the human physiological pH.…”

Graphene based catalysts

“…Electrodes modified with a graphene based electrocatalyst have been used for detecting various inorganic or organic electroactive compounds, such as hydrogen peroxide (H 2 O 2 ), b-nicotinamide adenine dinucleotide (NADH), acetaminophen (APAP), dopamine (DA), ascorbic acid (AA), uric acid (UA) and matrine. 219,221,[226][227][228][229][230][231][232][233][234][235][236][237] A typical electrocatalyst for this purpose is rGO and the simplest sensing electrode is an rGO modified glassy carbon electrode (rGO-GC). The rGO-GC electrode has been explored for sensing DNA, H 2 O 2 , NADH, APAP, DA, UA or AA.…”

“…L-Cysteine functionalized GO (LC-GO) can enhance the oxidation of matrine, and a LC-GO-GC electrode can detect matrine in a concentration range of 4 mmol L À1 to 0.1 mmol L À1 . 236 A variety of electrochemical sensors based on the graphene composite catalysts containing metals have also been developed. Titanium nitride/nitrogen-doped graphene (TiN/NG) provided a reliable platform for the determination of NADH with a linear dynamic range of 2.0-687 mM at a working potential of 0.1 V (vs. Ag/AgCl).…”

A green electrochemical sensor based on a poly(ionic liquid)–graphene nanocomposite modified electrode for Sudan I determination

“…The electrochemical effective surface areas of bare GCE and PIL-EG/GCE were calculated by the slope of the plot of Q versus t 1/2 obtained by chronocoulometry using 1mmol/L K 3 [Fe(CN) 6 ] as model complex (the diffusion coefficient D of K 3 [Fe(CN) 6 ] is 7.6×10 -6 cm 2 /s) 30 based on the equation of Q = 2nFAc(Dt) 1/2 /π 1/2 + Q dl + Q ads 31 , where A is the electrode surface area, n is the number of electrons transferred, F is the Faraday constant, c is the concentration of substrate, D is the diffusion coefficient, Q dl is double layer charge which could be eliminated by background subtraction and Q ads is the Faradic charge. In this study, the corresponding A of bare GCE and the modified electrode were obtained to be 0.0397 and 0.2417 cm 2 .…”