Electrochemical sensors for shellfish contaminants: from proof-of-concept to analytical relevance

Background: Shellfish contamination represents a complex analytical challenge due to the coexistence of chemically and biologically diverse hazards, including heavy metals, marine biotoxins, pathogenic microorganisms, and allergenic proteins. Their heterogeneous physicochemical properties, toxicity mechanisms, and regulatory thresholds require highly sensitive, selective, and matrix-tolerant analytical strategies. Scope and approach: This review critically examines recent advances (2023–2026) in electrochemical sensors and biosensors developed for shellfish safety assessment. Emphasis is placed on how transduction modes, recognition elements, assay architectures, and nanomaterial integration are tailored to address analyte-specific constraints and matrix-related interferences. Rather than providing a descriptive inventory of sensor platforms, the analysis focuses on comparative evaluation of sensing strategies and performance trade-off. Key findings and conclusions: Electrochemical approaches show strong potential for rapid, cost-effective, and on-site detection of shellfish contaminants. However, key limitations persist, including matrix effects, insufficient validation in real samples, reproducibility issues, and limited operational robustness. Trade-offs between sensitivity, assay complexity, and portability often hinder practical implementation. Future research should prioritize standardized validation protocols, simplified assay formats, and reliable performance under field conditions to enable the transition from proof-of-concept devices to routine monitoring tools.