A system and method includes a test container for detecting a target substance in a consumable sample, where the test container includes a test container body defining a test container top, a test container bottom opposing the test container top, a first chamber proximal the test container top, and a second chamber proximal the test container bottom, a magnetic diaphragm situated between the first chamber and the second chamber, the magnetic diaphragm obstructing flow of the consumable sample, and the magnetic diaphragm including a magnetic element embedded in the magnetic diaphragm, and a driving element geometrically complementary to the first chamber, the driving element including a consumable sample grinding feature protruding from a surface of the driving element.