Glutathione Modified Gold Piezoelectric and Voltammetric Sensors for Determination of Mercury in a Wide Concentration Range

Abstract

Glutathione-modified Au electrodes (Au-SG) deposited on a piezoelectric quartz crystal resonators were investigated for sensor applications for mercury(II). Owing to the stable background resulting from well ordered Au-SG self-assembled monolayer film, very small accumulations of mercury could be utilized in Hg(II) determination. Typically, the accumulations ranging from qHg = 0.1 down to 0.0005 ML (equivalent Hg monolayers) could be used. This contributs to the considerable reduction of the analysis time. The lower detection limit of Hg, LDO = 0.3 ppb has been achieved using slow scan stripping voltammetry and was further enhanced using differential pulse technique to 0.05 ppb. Moreover, the analysis can also be performed in acidic environment where other electrode modifiers become inactive.

Keywords

• glutathione SAM
• Hg stripping voltammetry
• nanogravimetry
• adsorptive stripping voltammetry (AdSV)
• differential pulse (DP) stripping voltammetry
• modified-Au EQCN.