Advances in flexible surface-enhanced Raman scattering sensors for foodborne pathogen detection

Abstract Foodborne pathogens pose persistent threats to global health and food security, necessitating rapid and non-destructive detection technologies compatible with irregular food surfaces. Conventional rigid surface-enhanced Raman scattering (SERS) substrates struggle with poor conformal contact and sampling inefficiency in real-world applications. This review highlights the transformative role of flexible SERS sensors, which combine mechanical adaptability with plasmonic enhancement to enable in situ pathogen detection on complex food matrices. We systematically analyze advances from 2020 to 2025, focusing on three parts: (1) flexible sensing strategies integrating label-free fingerprinting and specific recognition elements to enhance specificity in complex food matrices; (2) flexible substrate designs using natural/synthetic polymers and hybrid composites to balance optical performance and durability; and (3) conformal sampling methods enabling effective pathogen capture. Critical challenges in sensitivity-stability trade-offs, field-portable integration, and spectral reproducibility are being addressed through emerging solutions such as machine learning-assisted calibration and self-cleaning interface prototypes. By bridging material innovation with practical deployment needs, flexible SERS platforms demonstrate practical potential for decentralized food safety monitoring. Future progress hinges on scalable fabrication techniques and AI-driven systems integrating machine learning for predictive monitoring, where real-time pathogen detection synergizes with blockchain-enabled traceability to enable proactive risk management throughout supply chains.