There is provided a lateral flow assay device for detecting the presence
or quantity of an analyte residing in a test sample where the lateral
flow assay device has a porous membrane in communication with a wicking
pad. The porous membrane has a detection zone which has a chromophore
configured to chemically react with an analyte or a secondary trigger or
a reaction product from the analyte and a trigger generating reagent(s),
to generate a visually detectible signal. Additional chrmophore zones may
be located downstream from the first chrmophore zone to generate signals
of varying color. Scavenging zones may be included between chromophore
zones to attenuate the signal by reacting with the analyte without
generating a visually detectable signal.