Electrochemical cell

An electrochemical sensor for analytic determination using a liquid sample comprises a substantially flat strip having at least two lateral edges (17), a sample-receiving cell (11) within the strip, at least two electrodes (13) in communication with the cell (11), and a notch (16) in at least one of the lateral edges (17), wherein the notch (16) is in communication with the cell (11) and allows entry of the liquid sample into the cell (11). The strip may further comprise a vent (16) in communication with the cell (11), the vent (16) being adapted to allow air to escape the cell (11) in order to facilitate entry into the cell (11) by the liquid sample. The cell (11) may contain, for example, at least one of a catalyst, a redox reagent and a surfactant.