Fecha de publicación: -- Fuente: PubMed "essential OR oil extract" Anal Chim Acta. 2026 Dec 15;1427:346405. doi: 10.1016/j.aca.2026.346405. Epub 2026 Oct 16.ABSTRACTBACKGROUND: Establishing sensitive and reliable analytical techniques for detecting antibiotic residues is now a pressing scientific objective, essential for strengthening food safety surveillance and enabling regulatory measures. Recently, nanomaterial-based sensors have attracted increasing attention in antibiotic detection due to their high sensitivity. However, the preparation of nanomaterials is often complex, costly, and environmentally unfriendly.RESULTS: By leveraging the safety and cost-effectiveness of culturing probiotic E. coli Nissle 1917 (EcN), here we developed fluorescent protein-expressing EcN biomass as a magnified nanomaterial for biosensing. The EcN cells were further modified with allosteric aptamer probes on their surface for the specific recognition and enrichment of the target. The target-bound EcN was then captured by the immobilized complementary DNA, where the captured EcN quantity exhibited a linear correlation with the target concentration. Using oxytetracycline as a target model, the fluorescent EcN biosensor achieved a limit of detection of 0.1 pM, with a correlation coefficient R2 of 0.9982 in the range of 0.2-1000 pM. By combining aptamer recognition with bacterial centrifugation, the EcN biosensor demonstrated excellent specificity and anti-interference capability, yielding 88-126% recovery rates in spiked food matrices.SIGNIFICANCE AND NOVELTY: This study presents a conceptually novel biosensing platform that, for the first time, harnesses the probiotic bacterium E. coli Nissle 1917 (EcN) as a live, self-amplifying nano-reporting probe for ultratrace antibiotic detection. This EcN platform circumvents the inherent drawbacks of conventional nanomaterials-namely, costly synthesis, tedious characterization, and environmental incompatibility. Hence, the as-developed method would provide a tool for the monitoring of trace antibiotic residues in food safety applications.PMID:43003593 | DOI:10.1016/j.aca.2026.346405