Phage tail Fiber-based electrochemical biosensor for rapid detection of Cronobacter spp. in food

Cronobacter spp. is a high-risk foodborne pathogen that poses a significant threat to neonates. It can cause severe invasive infections such as meningitis and necrotizing enterocolitis, with a case fatality rate of up to 80%. Therefore, developing rapid and precise detection techniques is critical for effectively preventing and controlling infections caused by Cronobacter spp. This study presents an innovative electrochemical biosensor based on phage-derived tail fiber protein (TFP08) for the rapid and specific detection of Cronobacter spp. in food samples. The biosensor employs a ternary nanocomposite system comprising gold nanoparticles, nickel ions, and graphene oxide to immobilize TFP08 and enhance the electrical signal. It enables sensitive detection of the target bacteria through differential pulse voltammetry. The developed platform achieves detection within 30 min over a linear range of 2.3 × 10¹ to 3.7 × 10⁷ CFU/mL, with a limit of detection as low as 23 CFU/mL. When tested in spiked infant formula and lettuce samples, the biosensor exhibited excellent recovery rates (99.23-102.46%) and high reproducibility (relative standard deviation ≤1.17%), This demonstrates its reliability and accuracy in complex food matrices. This work presents a rapid and accurate diagnostic platform for detecting Cronobacter spp., providing significant advantages for food safety monitoring and public health protection.