Fabrication Of Gold Nanoparticles-Modified Glassy Carbon Electrode And Its Application For Voltammetric Detection Of Cr(III)

A sensitive and selective differential pulse stripping voltammetric (DPSV) method is presented for the determination of trace amount Cr(III) using glassy carbon electrode (GCE) modified with gold nanoparticles (AuNPs). The method includes AuNPs fabrication and self-assembly GCE modification. This processes replaced the –H groups with –NH2 groups on the surfaces of GCE which increased the number of AuNPs attached to it. The GCE modified with AuNPS was used as electrochemical sensor of Cr(III) for the first time that gave a wide linear range from 0.5 to 75 ppb and a very low detection limit of 10 ppt (equivalent to 0.19 nM). The electrode exhibited high reproducibility in repetitive measurements with a relative standard deviation better than 2.4%. The effect of interfering ions study showed that Cu(II), Cd(II), Zn(II) Cr(VI), Ni(II) and Fe(III) ions did not have a significant effect on the measurement.