Biomarker concentration and signal amplification for use in paper-based immunoassays and a single platform for extracting, concentrating, and amplifying DNA

In various embodiments methods and devices are provided for the detection and/or quantification of an analyte. In certain embodiments a device is provided comprising an aqueous two-phase system (ATPS) comprising a mixed phase solution that separates into a first phase solution and a second phase where, in use, said first phase solution becomes a leading phase and said second phase solution becomes a lagging phase; a lateral-flow assay (LFA); and a probe and/or a development reagent, where in use, said probe associates with said first phase solution in said leading phase of said ATPS and/or said development reagent associates with said second phase solution in said lagging phase of said ATPS. In certain embodiments a "one-pot" system of purifying and amplifying a nucleic acid is provided utilizing, e.g., an ATPS and isothermal amplification reagents.