Micro- and Nanoplastic Water Contamination: Comparative Review of Classical Analytical Methods and Advanced Sensors

Micro- and nanoplastics have emerged as persistent, mobile water contaminants capable of carrying co-pollutants such as phthalates, polycyclic aromatic hydrocarbons and antibiotic-resistant pathogens, yet detection methods for this size range remain fragmented across classical analytical chemistry and a rapidly diversifying set of electrochemical, optical and biosensor platforms. This review compiles and classifies 53 original research articles published between 2021 and mid-2026, identified through a PRISMA-guided search of Google Scholar and ScienceDirect, covering detection principle, sensor type, sample matrix, target polymer, water source and particle size class. Optical techniques account for over half of the studies, mass spectrometry and electrochemical sensors divide most of the remainder, and biosensors show the fastest growth in recent years. Water dominates as the tested matrix, but seven in ten water-based studies rely on laboratory-spiked or unspecified samples rather than named environmental water, and nearly half now address the nanoplastic fraction. These findings are interpreted alongside contamination pathways, including atmospheric deposition, and against current EU and WHO frameworks, which place microplastics and antimicrobial resistance indicators on a watch list pending harmonised testing rather than binding limits. The review identifies matrix realism, nanoplastic capability and monitoring frequency as the central bottlenecks separating current detection science from field-ready water monitoring.