Upconversion fluorescent strip sensor for rapid determination of Vibrio anguillarum

Here, we report a simple and ultrasensitive upconversion fluorescent strip sensor based on NaYF 4 :Yb,Er nanoparticles (NPs) and the lateral flow immunochromatographic assay (LFIA). Carboxyl-modified β-NaYF 4 :Yb,Er NPs were successfully synthesized by a facile one-pot solvothermal approach, upon further coupling with monoclonal antibody, the resultant UCNPs-antibody conjugates probes were used in LFIA and served as signal vehicles for the fluorescent reporters. V. anguillarum was used as a model analyte to demonstrate the use of this strip sensor. The limit of the detection for the fluorescent strip was determined as 10 2 CFU mL −1 , which is 100 times lower than those displayed by enzyme-linked immunosorbent assays, while the time needed for the detection was only 15 min. Furthermore, no cross-reaction with other eight pathogens was found, indicating the good specificity of the strip. This developed LFIA would offer the potential as a useful tool for the quantification of pathogens analysis in the future. We report a simple and ultrasensitive UC fluorescent strip sensor based on NaYF 4 :Yb,Er nanoparticles and the LFIA. The limit of the detection for the fluorescent strip was determined as 10 2 CFU mL −1 ; good specificity and stability of the strip sensor were also demonstrated.