Aptamer-Based Biosensors for Rapid Detection and Early Warning of Food Contaminants: From Selection to Field Applications

Aptamer-based biosensors have emerged as an important and promising technology for applications in food safety, environmental monitoring, and pharmaceutical analysis. Obtained via Systematic evolution of ligands by exponential enrichment (SELEX) screening, these recognition elements exhibit antibody-comparable affinity and specificity, alongside superior chemical stability, easy synthesis, and broad target adaptability. Substantial advances in the field have been marked by the systematic development of food contaminant-specific aptamers, elucidation of their binding mechanisms, and construction of versatile biosensing platforms. The integration of these aptamers with conventional electrochemical and optical sensors has substantially enhanced detection sensitivity and lowered detection limits, particularly for trace-level analytes in complex food matrices. Furthermore, the integration of aptamer technology with novel nanomaterials has facilitated the development of high-performance detection platforms for a wide range of food contaminants, including heavy metals, antibiotics, foodborne pathogens, mycotoxins, pesticides, and food additives. This review systematically summarizes recent advances in SELEX techniques for aptamer screening, highlights the application of aptamer-based biosensors in detecting these contaminants, and discusses current challenges and future prospects in the field of food safety, which establishes a comprehensive framework to advance aptamer-based biosensing technologies for rapid detection and early warning in food safety monitoring.