This invention discloses an immunochromatographic assay device to detect and quantify analytes. The device utilizes up-converting luminescent probes to detect time-resolved luminescence signals. Because the unconverting luminescent probes can have relatively long emission lifetime, background interference from sample autofluorescence and light scattering from excitation source can be easily eliminated through delayed luminescence detection. Furthermore, the up-converting luminescent probes can be excited by near Infrared (IR) or IR light sources. In comparing with UV and visible lights, the near IR and IR lights can penetrate deeper into sample matrices and more effectively excite the probes, but not the sample matrices, resulting in less background and higher detection sensitivity. A simple and low cost reader can be designed to measure the delayed up-converting luminescence of long lifetime that does not use expensive optical filters and mirrors.
展开▼
