Device and method for measuring multiple analyte concentrations in a measuring medium

A device for measuring a first analyte concentration and a second analyte concentration in a measuring medium, the device comprising:

• a sample cell adapted to receive a measuring medium and including an inlet, an outlet and a window, wherein the inlet is configured to enable introducing the measuring medium into the sample cell, and the outlet is configured to enable evacuating the measuring medium from the sample cell;
• a first light source unit configured and directed to emit a first light into the sample cell via the window;
• a first detector unit configured and directed to detect the first light exiting the sample cell via the window;
• a functional element disposed within the sample cell such that the functional element is in contact with the measuring medium;
• a second light source unit configured and directed to emit a second light onto the functional element via the window, wherein the functional element comprises a functional layer including luminophores adapted to emit a third light upon stimulation with the second light, the third light depending on a presence of a second analyte in the measuring medium;
• a second detector unit configured and directed to detect the third light from the functional element via the window;
• and
• a control unit configured to control the first light source unit, the first detector unit, the second light source unit and the second detector unit, wherein the control unit is configured to analyze the detected first light to determine a first value representing the first analyte concentration in the measuring medium and is configured to analyze the detected third light to determine a second value representing the second analyte concentration in the measuring medium.