Fig. 6From: Fabrication of novel polymer-modified graphene-based electrochemical sensor for the determination of mercury and lead ions in water and biological samplesa Cyclic voltammograms of HgCl2 (1 mM) at PGMGPE with solution pH 3.5, 4.0, 4.5, 5.0, and 5.5. b Epa vs pH. c Ipa vs pHBack to article page