Design of time-resolved fluorometer based on immunochromatography

Abstract

This paper introduces the design of a novel time-resolved fluorometer based on immunochromatograghy. Different from the other time-resolved fluorometers, it tests the immunochromatographic strip which is labeled with lanthanide ions and their chelates. This instrument can provide a rapid, quantitative measurement of analytes present in samples without any washing steps and it can be used to carry out point-of-care test (POCT). The immunochromatograghy-based timeresolved fluorometer is composed of a specific optical sensor, a scanning stage, a signal processing system and a computer control system. The light from UV LED is focused on the test strip by a condense lens group in the optical sensor. If the labels are present in samples, the fluorescence at 613nm will be exited (when Eu 3 + chelate is used for marking substance). After a delay of some microseconds, the fluorescence will be collected by the optical sensor and converted into electronic signal by a photomultiplier tube (PMT). The concentration of the sample can be calculated through the standard working curve of this instrument. By testing, the sensitivity is several ng/ml level (when Eu 3 + chelate is used for marking substance), test linear range is from several ng/ml to 10 3 ng/ml, in which correlation coefficient is 99.97%.