The present application relates to a molecular exchange device (1) for use with an analysis and control apparatus and a method of manufacturing a molecular exchange device. The molecular exchange device comprises a casing (2), extending from a proximal end (3) to a distal end (4), supporting at least two fluid passageways (7a, 7b) extending from the proximal end to the distal end； the casing comprising at least one exchange aperture (9a, 9b) between the distal end and the proximal end, wherein a portion of the fluid passageway exposed by the exchange aperture is porous
