Femtosecond-Laser-Inscribed Dual-Resonance LPFG Biosensor for Ultrasensitive (1nM) Aflatoxin B1 Screening in Food

Abstract Food safety monitoring demands rapid and sensitive aflatoxin detection technologies that surpass current national standards (10⁻⁸ mol/L). Here we report a femtosecond-laser-Inscribed dual-resonance LPFG biosensor achieving 1nM(10⁻⁹ mol/L) detection limit. Through point-by-point grating inscription and optimized silanization-mediated antibody immobilization, our platform demonstrates that the sensor exhibits excellent selectivity for AFB1 detection,good repeatability, and exceptional sensitivity with a response of 3.768 nm/nM in the critical 5–15 nM detection range, significantly surpassing conventional approaches,in addition, the sensor demonstrated excellent recovery rates of 80.5%-102.9% for AFB1 in complex food matrices, confirming its robust performance even in challenging sample environments. This study provides a highly efficient and scalable solution for food safety monitoring and holds great promise for applications in the field of food quality detection.