Electrochemical approaches for detecting micro and nano-plastics in different environmental matrices

Microplastics and nanoplastics are synthetic polymer particles < 5 mm and < 1 μm respectively, have emerged as ubiquitous environmental contaminants with significant implications for ecosystem and human health. Conventional detection methods including FTIR spectroscopy, Raman microspectroscopy, and pyrolysis-GC/MS face substantial limitations including poor spatial resolution, matrix interference, time-intensive analysis, and high costs that hinder widespread monitoring efforts. Electrochemical sensing strategies offer promising alternatives, leveraging the inherent properties of plastic particles through direct detection via particle collision, indirect detection of electroactive additives, and recognition-based approaches using surface modifications. These methods provide exceptional sensitivity with detection limits reaching nanomolar concentrations, rapid response times of seconds to minutes, and significant cost advantages over traditional techniques. Advanced electrode modifications incorporating nanomaterials, molecularly imprinted polymers, and biological recognition elements enhance selectivity and sensitivity for diverse environmental matrices including water bodies, food products, and biological samples. Portable electrochemical sensors enable real-time, on-site monitoring capabilities previously unattainable with laboratory-based methods. Despite challenges in selectivity, reproducibility, and matrix interference, emerging hybrid platforms integrating electrochemical detection with complementary techniques, machine learning algorithms, and automated systems demonstrate significant potential for revolutionizing microplastic monitoring. This review critically evaluates current electrochemical approaches, identifies key limitations, and outlines future research directions toward practical field-deployable sensors for comprehensive environmental surveillance.