Determination of heavy metals in corn (Zea Mays L.) using silver nanoparticles/graphene/nafion modified glassy carbon electrode

S. Palisoc¹², A.J. Gallardo¹, C.B. Laurito¹ and M. Natividad¹²*

¹De La Salle University, Condensed Matter Research Laboratory, Physics Department, 2401 Taft Avenue, Manila, 922, Philippines
²De La Salle University, Condensed Matter Research Unit, CENSER, 2401 Taft Avenue, Manila, 922, Philippines
*Correspondence: michelle.natividad@dlsu.edu.ph

Abstract:

Silver nanoparticles (AgNP)/graphene/Nafion modified glassy carbon electrodes were fabricated for the determination of trace amounts of cadmium (Cd²⁺) and lead (Pb²⁺) via anodic stripping voltammetry (ASV). The electrode modifiers and the ASV parameters were optimized. The fabricated electrode was characterized by field emission scanning electron microscopy and energy dispersive x-ray spectroscopy. A linear relationship between anodic peak current and heavy metal concentration was obtained in the range of 25 parts per billion (ppb) to 250 ppb. The limit of detection of the modified electrode is 25 ppb for both Cd²⁺ and Pb²⁺, while the limits of quantitation are 155.7 ppb for Cd²⁺ and 159.5 ppb for Pb²⁺. Real sample analysis using corn plant and soil samples was performed to show the utility of the fabricated electrode in sensing applications. Trace amounts of Cd²⁺ and Pb²⁺ were found in the said samples.

Key words:

anodic stripping voltammetry, graphene, heavy metals, Nafion, silver nanoparticles