Abstract: A method for measuring the presence or amount of at least one analyte in a sample mixture that includes capturing a first analyte on a first cavity arrangement structure having a plurality of cavities; capturing an impurity present in the sample mixture or a second analyte on a second cavity arrangement structure that has a plurality of cavities and that differs from the first cavity arrangement structure in at least one of cavity size and surface modification; and after these steps, irradiating the first cavity arrangement structure or the first and second cavity arrangement structures with electromagnetic radiation and detecting the characteristics of scattered electromagnetic radiation.

Abstract: A filter device through which a fluid containing a target substance and a coarse substance larger than the target substance is passed to selectively collect the target substance from the fluid. The filter device includes a prefilter that removes the coarse substance and a collection filter that collects the target substance. The prefilter and the collection filter are arranged in series such that the fluid passes through the prefilter and then through the collection filter. The prefilter includes a cavity arrangement structure having a pair of opposing main surfaces and a plurality of cavities extending through both main surfaces.