Multiplexed lateral flow assays, related methods, and devices are disclosed which are capable of simultaneously detecting multiple analytes. The assays are preferably immunoassays and can be multiplexed spatially, spectrally, and both spatially and spectrally. Multiplexed assays are disclosed employing quantum dots for applications including the detection of human proteins and the monitoring of microorganisms relevant to water contamination. The invention is widely adaptable to a variety of analytes such as biowarfare agents, human clinical markers, and other substances.