The invention comprises a device for detecting an analyte in a liquid sample deposited on a first portion of the device for transport to a second portion of the device that is in fluid contact with the first portion. In specific embodiments, the device comprises a labeled conjugate comprising a binding member reactive with a first epitope of the analyte and a label comprising a gold colloid, preferably having a mean particle size of 50 nm to 100 nm. In further embodiments, the device comprises a capture component comprising polymerized streptavidin. The diagnostic device is particularly useful in the preparation of pregnancy test kits.