Dual nanoparticle-enhanced biophotonic fiber sensor for highly sensitive and selective detection of pseudomonas aeruginosa in food safety applications

• The sensor is composed of MMF and SCF and has a crab-shaped structure. • AuNPs/PtNPs were used to excite the LSPR effect. • The developed sensor has high sensitivity, excellent specificity, and operation-simplicity. • Ultra-low concentration of P. aeruginosa of 2.6 CFU/mL can be detected. Pseudomonas aeruginosa ( P. aeruginosa ), as a foodborne pathogen, is often underestimated in the field of food safety. In light of this, the development of a sensor for detecting P. aeruginosa that possesses both high sensitivity and high selectivity is of great significance for food safety monitoring and the medical health field. Based on the localized surface plasmon resonance (LSPR) effect, this study designs and constructs a novel biophotonic fiber sensor using gold nanoparticles (AuNPs) and platinum nanoparticles (PtNPs) with significant LSPR effects, aiming to efficiently detect P. aeruginosa . The core of the sensor is to fix specific antibodies on the surface of nanoparticles and achieve detection by monitoring the LSPR spectral shift triggered by the binding of bacteria to antibodies. The sensor demonstrates a low detection limit of 2.6 CFU/mL, which represents a significant advantage in the current technological context. Furthermore, this study enhances the selectivity of the sensor by functionalizing antibodies to meet the specific requirements for screening P. aeruginosa in food. To comprehensively evaluate the performance of the sensor, we tested its stability, repeatability, and selectivity, with results showing excellent performance. The formation of biofilm by P. aeruginosa is one of its major virulence factors, and our sensor can also accurately detect the presence of biofilm. Further application of the sensor in tests simulating real-world environments indicates that the sensor has the potential for practical application. These advantages not only confirm the high efficiency of the proposed sensor in accurately detecting P. aeruginosa but also highlight its significant application prospects in the field of food safety detection.