Rapid quantitative detection of by lateral-flow immunoassay and up-converting phosphor technology-based biosensor.

Up-converting phosphor technology (UPT)-based lateral-flow immunoassay has been developed for quantitative detection of rapidly and specifically. In this assay, 400 nm up-converting phosphor particles were used as the reporter. A sandwich immumoassay was employed by using a polyclonal antibody against F1 antigen of immobilized on the nitrocellulose membrane and the same antibody conjugated to the UPT particles. The signal detection of the strips was performed by the UPT-based biosensor that could provide a 980 nm IR laser to excite the phosphor particles, then collect the visible luminescence emitted by the UPT particles and finally convert it to the voltage as a signal. and stand for the multiplied voltage units for the test and the control line, respectively, and the ratio / is directly proportional to the number of in a sample. We observed a good linearity between the ratio and log CFU/ml of above the detection limit, which was approximately 10 CFU/ml. The precision of the intra- and inter-assay was below 15% (coefficient of variation, CV). Cross-reactivity with related Gram-negative enteric bacteria was not found. The UPT-LF immunoassay system presented here takes less than 30 min to perform from the sample treatment to the data analysis. The current paper includes only preliminary data concerning the biomedical aspects of the assay, but is more concentrated on the technical details of establishing a rapid manual assay using a state-of-the-art label chemistry.