Novel 4-carboxyphenyl-grafted screen-printed electrode for trace Cu(II) determination

This paper reports the interest of 4-carboxyphenyl-grafted screen-printed electrodes (4-CP-SPEs) for trace Cu(II) measurement in water samples. These novel sensors were easily prepared via electrochemically reduction of the corresponding diazonium salt. Detection of Cu(II) was then achieved by immersing the grafted electrode into the sample solution for 10 min, followed by the electrochemical measurement of accumulated metallic ions.The efficiency of the Cu(II) adsorption at the grafted layer was clearly demonstrated. 4-CP-SPEs were able to detect and quantify Cu(II) as low as 5 × 10−9 and 10−8 M in a large ionic strength range. Moreover, no major interference of Pb(II) in the determination of Cu(II) is expected in natural water. Electrodes were finally successfully applied for Cu(II) determination in tap water and in estuarine water demonstrating the convenience of such sensors for environmental analysis.