“Stick-and-Sense”: The New Flexible Paper-Based SERS Sensor for Ultra-Sensitive Pathogen Detection – New Article 📄🧫🦠

Ensuring the safety of our food and drinking water remains a critical challenge for global public health. Traditional methods to identify waterborne and foodborne pathogens—such as Escherichia coli—are reliable but notoriously slow, expensive, and tied to specialized laboratory infrastructures. To bridge this gap, a multidisciplinary research team has developed an innovative, low-cost solution: a flexible “Stick-and-Sense” paper tape sensor that brings high-sensitivity laboratory testing directly into the field.

Published in the prestigious journal Food Chemistry, the study introduces a Surface-Enhanced Raman Scattering (SERS) biosensor created by coating standard commercial masking tape with a self-assembled monolayer of gold nanoparticles (Au NPs).

Dual-Mode Capability: Water and Complex Food Matrices The true power of this platform lies in its versatile dual-mode detection strategy:

1. Label-Free in Water: When deployed in aqueous environments, the sensor identifies and discriminates among different bacterial strains (such as E. coli, Enterococcus, and Citrobacter) based solely on their unique molecular Raman fingerprints combined with Principal Component Analysis (PCA). In this mode, it achieves a remarkable detection limit of just 26 CFU/mL.
2. Targeted Immunodetection in Food: Complex matrices like milk present major background interference for standard sensors. To solve this, the substrate was functionalized with specific anti-E. coli antibodies. This allows the sensor to capture and isolate the target pathogen directly from commercial milk, achieving an experimental limit of detection as low as 25 CFU/mL.

High Performance at an Accessible Cost Thanks to the natural porosity of the paper support, the gold nanoparticles organize into a tight three-dimensional network of plasmonic “hot spots”. This arrangement grants the substrate an extraordinary electromagnetic enhancement factor of approximately 10^7 , putting its performance on par with fragile, expensive rigid substrates like silicon or glass.

Furthermore, a preliminary economic evaluation highlights the high commercial viability of the device, with a material cost estimated at just around €0.19 per fully functionalized sensor. This combination of flexibility, high sensitivity, and extreme affordability marks a major milestone toward immediate, on-site food safety and environmental screening.

Acknowledgments: This groundbreaking research was carried out under the brilliant guidance of Dr. Lucia Petti and her outstanding team at the Institute of Applied Sciences and Intelligent Systems “Eduardo Caianiello” (ISASI – CNR) in Pozzuoli. We extend our deepest gratitude to the group for their continuous effort in translating advanced nanotechnology into real-world diagnostics.

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DOI: 10.1016/j.foodchem.2026.149599