Development of Electrochemical Sensor for Simultaneous Determination of Cd(II) and Hg(II) Ion by Exploiting Newly Synthesized Cyclic Dipeptide

作者：Rahman Nadiah Abdul^*; Yusof Nor Azah; Maamor Nor Amirah Mohd; Noor Siti Mariam Mohd

来源：International Journal of Electrochemical Science, 2012, 7(1): 186-196.

DOI：10.1016/s1452-3981(23)13330-x

• electrochemical sensor
• modified electrode
• electrocatalytic, peptide

An electrochemical sensor for simultaneous detection of Cd(II) and Hg(II) were developed by using MWCNT/peptide modified Au electrode with cyclic voltammetry (CV). Peptides were synthesized by cyclooligomerisation of cysteine monomers in the presence of diphenylphosphoryl azide (DPPA). The synthesized peptides were attached to the Au electrode and the experimental conditions such as electrochemical characterization, supporting electrolyte, pH and scan rates were optimized. The developed electrochemical sensor was found sensitive toward simultaneous determination of Cd(II) and Hg(II). The modified Au electrode were reproducible with R. S. D value of 2.25% and had significantly superior analytical performance compared to the unmodified electrode. The slope value of log I-p versus log v is 0.61-0.85 demonstrate that the modified Au electrode undergoes diffusion-adsorption controlled process. The sensitivity expressed as the slope of linear region of calibration curve was 6 x 10(-6) Appm(-1) in borate buffer (pH 3) and 8 x 10(-7) Appm(-1) in acetate buffer (pH 2). The limit of detection (L.O.D) of Cd(II) is 2.749 x 10(-8) M whereas the limit of detection of Hg(II) is 9.068 x 10(-10) M. The developed electrochemical sensors were applied in real industrial waste water sample of electroplating industry and wood industry for simultaneous determination of Cd(II) and Hg(II). The results of the waste water sample analysis from the developed method showed a comparable result with the ICP-OES method.

• 出版日期2012-1