Device for sensing contaminants

摘要

This invention relates to a test strip comprising a support having thereon a non-sampling area and a sampling area wherein said sampling area further comprises a sampling layer which can react with a target species to form or release a signal compound which is capable of effecting a reaction with silver halide to form a latent image, and a signal amplification layer comprising silver halide. It further relates to a kit containing the test strip and a method of using the test strip.