A sensitive voltammetric sensor, a graphene-modified glassy carbon electrode (GR/GCE), for the detection of trace amounts of curcumin is proposed. The GR/GCE was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrochemical behavior of curcumin at the GR/GCE was investigated by CV and liner sweep voltammetry (LSV). The reaction mechanisms of curcumin on the GR/GCE were also investigated and discussed systematically. In addition, the currents measured by LSV presented a good linear relationship with curcumin concentrations in the range of 5.0 Â 10 À8 to 3.0 Â 10 À6 mol L À1 , with a low detection limit of 3.0 Â 10 À8 mol L À1 . The method was also applied successfully to detect curcumin in a Curcuma longa L. sample with high selectivity and accuracy, as well as good recovery.

No abstract

No abstract

No abstract

No abstract

A novel self-assembly modified carbon paste electrode based on ethylenediamine and graphene oxide was proposed as a highly sensitive electrochemical sensor for detection of malachite green. The manufacturing operation of the recommended sensor was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The electrochemical response of malachite green at this sensor was investigated in detail and a new electroanalytical method was erected with high sensitivity and selectivity. The proposed method exhibited good linearity for malachite green over the range from 8.0 Â 10 À9 mol L À1 to 8.0 Â 10 À7 mol L À1 with the detection limit of 5 Â 10 À9 mol L À1 (S/N ¼ 3) by differential pulse voltammetry under optimum conditions. Finally, the practical application was proven by spiking malachite green standards in lake water with recoveries ranging from 98.80% to 101.10%, showing a satisfactory result.

No abstract

A simple sensor for highly sensitive determination of natamycin based on a single-walled carbon nanotube composite poly(l-serine) film modified glassy carbon electrode was established, which was applied in commercially available claret and beverage analysis.