Microplastic (MP) pollution poses a major concern, especially in aquatic environments, necessitating efficient detection technologies to safeguard marine life as well as human health. However, conventional detection methods like Fourier transform infrared spectroscopy require complex equipment and are often time-consuming, limiting their applicability for real-time monitoring. In this regard, electrochemical sensing methods, specifically those based on metal oxide electrodes, are highly promising for quick and sensitive detection of MPs.
In a new study, a team of researchers led by Professor Sadia Ameen from the Department of Bio-Convergence Science, Jeonbuk National University, Republic of Korea, has systematically reviewed and summarized the paradigm shift in MP detection methods—from expensive and time-consuming spectroscopic analysis to rapid and economical electrochemical sensing using metal oxide electrodes. The study was made available online on December 2, 2025, and was published in Volume 49 of the journal Trends in Environmental Analytical Chemistry on March 1, 2026.
"Our study provides mechanistic insights that are often missing with a detailed explanation of how MPs interact with metal oxide electrode surfaces, including impedance changes and interaction-induced current transients," says Prof. Ameen.
Notably, metal oxide nanostructures, such as zinc oxide, titanium dioxide, and hydrophobic cerium dioxide (CeO₂) with their large surface area and excellent conductivity, enable direct, high-sensitivity detection of trace MPs even in complex environments like wastewater or marine ecosystems, providing a practical on-site monitoring system.
In addition, the detection performance of metal oxide-based sensors can be dramatically enhanced by controlling the morphology and surface chemistry of metal oxides. Moreover, specific morphologies, such as nanorods, nanowires, or porous structures, form 'hotspots' that increase sensitivity compared to simple spherical particles.
Furthermore, a material engineering approach, such as hydrophobic CeO₂ nanoparticles that attract hydrophobic plastic particles, can aid in effective detection of MPs by selectively targeting MPs like polyethylene or polypropylene amidst various environmental interferents.
Metal oxide-based electrochemical sensors can be deployed for on-site and real-time monitoring of MPs in rivers, lakes, and oceans. Their portability, rapid response, and low cost make them suitable for continuous environmental surveillance programs, overcoming limitations of laboratory-based spectroscopic techniques. Moreover, electrochemical sensing platforms based on metal oxides can be used for routine screening of drinking water supplies to ensure compliance with safety standards, particularly for detecting trace-level MPs that escape conventional treatment methods. They can also be applied to detect MPs in seafood and processed food products, supporting food safety assessments and regulatory inspections.
Furthermore, due to their low management requirements, these systems are ideal for handheld or wearable sensing devices for field researchers and environmental inspectors conducting in situ analysis. Lastly, the sensors can aid in risk assessment of combined chemical-plastic exposure in environmental and biological samples, owing to their ability to detect hazardous pollutants adsorbed onto MPs.
"Metal oxide-based sensors will soon be integrated with the Internet of Things and artificial intelligence technologies. Over the next few years, the widespread adoption of this novel next-generation technology is expected to pave the way for improved public health protection, enhanced food safety and consumer confidence, acceleration of technological innovation and green industry growth, extensive interdisciplinary education and research, as well as global environmental resilience and climate adaptation," concludes Prof. Ameen.
