Fabrication of a Gold Nanoparticle Graphene Enhanced Screen-Printed Electrode for Highly Sensitive Electrochemical Monitoring of Heavy Metal Ions in Water

Abstract

Rapid, low-cost, in-field detection of heavy metal ions (HMIs) such as Pb(II) and Cd(II) remains a pressing analytical challenge for environmental monitoring. Electrochemical methods particularly anodic stripping voltammetry (ASV) variants offer excellent sensitivity, portability and low reagent use. This work presents a comprehensive research study: (1) a literature synthesis of recent advances in electrochemical HMIs sensing, (2) design and fabrication of a disposable screen-printed carbon electrode (SPCE) modified with a graphene-Au nanoparticle (AuNP) composite, (3) optimization of square-wave anodic stripping voltammetry (SWASV) parameters, and (4) analytical performance evaluation for Pb(II) and Cd(II) in laboratory and spiked real water samples. The proposed sensor shows, under optimized conditions, linear ranges suitable for regulatory limits, low limits of detection (LOD) in the sub-ppb to low ppb range, fast analysis (<10 min per sample), and good selectivity against common interferents. This paper includes an experimentally-oriented methodology, hypothetical but literature-anchored results and a critical discussion of strengths and limitations, with directions for future work toward commercial deployability.