The drive to understand biology and medicine at the molecular level with accurate quantitation demands much of current high-throughput analysis systems. Nanomaterials and nanotechnology combined with modern instrumentation have the potential to address this emerging challenge. Using a variety of nanomaterials for multiplex diagnostics and imaging applications will offer sensitive, rapid and cost-effective solutions for the modern clinical laboratory. New nanomaterials have been developed with optical-encoding capabilities for selective tagging of a wide range of medically important targets, including bacteria, cancer cells and individual molecules, such as proteins and DNA, in a single assay. We envision further development in this field will provide numerous advanced tools with increased sensitivity and improved multiplexing capability, for unique applications in molecular biology, genomics and drug discovery.