Copper Electrodes Modified with Gold Nanoparticles Detect Two Hazardous Contaminants (As, Cd) in Raw Milk

Abstract

Background: Milk contamination has been a longstanding global concern, with Heavy Metals (HM) like lead (Pb), mercury (Hg), arsenic (As), and cadmium (Cd) posing significant risks. These contaminants often infiltrate milk through contaminated water sources or during pasteurization. This study introduces a novel approach to detecting milk contaminants by analyzing the current– voltage (IV) characteristics of copper (Cu) electrodes modified with gold nanoparticle (AuNPs). Methods: Leveraging the exceptional conductivity of metal nanoparticles, electrons freely traverse the surface, facilitating electron movement across the copper substrate. Additionally, the nanoparticles serve as binding agents, aiding in the comparative detection of contaminants. This method enables the preliminary detection of two HM (As, Cd) by evaluating their current gains in milk supernatant samples at varying concentrations. Results: AuNPs deposited on Cu electrodes exhibited a linear IV trend, with a significant increase in current compared to bare electrodes. Spiked milk supernatant drops cast on the electrode system displayed a current gain, which was evaluated towards sensing application of HM ions in milk. The synthesized AuNPs underwent initial characterization using a UV-Vis spectrophotometer, revealing a prominent plasmonic peak around 520 nm, confirming nanoparticle formation. X-Ray Diffraction (XRD) analysis confirmed the Face-Centred Cubic (FCC) crystal structure. Conclusion: Notably, different concentrations (1 and 10 ppm) and types of HM (As, Cd, Hg, and Pb) in milk supernatant yielded varying current gains, providing insights specifically targeting As and Cd contamination. conclusion: Notably, different concentrations and types of heavy metals in milk supernatant yielded varying current gains, providing insights into specific heavy metal contamination.