NaBiF4 upconversion nanoparticle-based electrochemiluminescent biosensor for E. coli O157 : H7 detection† † Electronic supplementary information (ESI) available: SEM elemental mapping of (B) F, (C) Na, (D) Bi, (E) Yb and (F) Er according to (A) the original SEM image of NaBiF4 : Yb3+/Er3+ UCNPs. XRD pattern of NaBiF4 : Yb3+/Er3+ UCNPs in comparison with the standard peaks of hexagonal phase NaBiF4. Comparison of ECL intensity of NaBiF4 : Yb3+/Er3+ UCNPs in PBS (0.1 M, pH 7.4) with or without 0.1 M K2S2O8. Comparison of ECL intensity for different materials with or without doping elements. (A) SEM image and (B) EDS of NaBiF4 : Yb3+ UCNPs, (C) SEM image and (D) EDS of NaBiF4 UCNPs. Effect of the concentration of UCNPs solution on ECL intensity of NaBiF4 : Yb3+/Er3+ UCNPs/GCE. Effect of incubation time on ECL intensity of E. coli O157 : H7 antibody/Au/NaBiF4 : Yb3+/Er3+ UCNPs/GCE. The relationship between the ECL peak intensity and the logarithm of E. coli Top 10 concentrations with the a

ABSTRACT: Foodborne or water-borne pathogens pose great threats to human beings and animals. There is an urgent need to detect pathogens with cheap, rapid and sensitive point-of-care diagnostic assays. Herein, we report the electrochemiluminescent (ECL) behaviors of NaBiF4 : Yb3+/Er3+ upconversion nanoparticles (UCNPs) which were synthesized via a fast and environment-friendly method at room temperature for the first time. The UCNPs together with K2S2O8 exhibit high ECL intensity and stable cathodic signals. Further, the Au nanoparticles (Au NPs) and Anti-E. coli O157 : H7 antibody were assembled on the surface of UCNPs successively to construct a novel ECL immunosensor for the detection of deadly E. coli O157 : H7. The as-prepared ECL immunosensor reveals high sensitivity to E. coli O157 : H7 in a linear range of 200–100 000 CFU mL−1, and the minimum detection limit could reach up to 138 CFU mL−1. The designed UCNP-based biosensor demonstrates high specificity, good stability and remarkable repeatability, and the strategy will provide a sensitive and selective method for rapid detection of E. coli O157 : H7 in food safety and preclinical diagnosis. The ECL behaviors of NaBiF4 : Yb3+/Er3+ UCNPs synthesized via a fast and environment-friendly method are reported for the first time. UCNPs-based ECL biosensor shows a wide detection range with low detection limit of 138 CFU mL−1 for E. coli O157 : H7.

SUBMITTER: Liu D 

PROVIDER: S-EPMC9589827 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature