A disc pump system comprising: a pump body having a cylindrical shape defining a cavity for containing a fluid, the cavity being formed by a side wall closed at both ends by circular end walls (12, 13), at least one of the circular end walls (12, 13) being a driven end wall having a central portion and a peripheral portion extending radially outwardly from the central portion of the driven end wall; an actuator operatively associated with the central portion of the driven end wall to cause an oscillatory motion of the driven end wall thereby generating displacement oscillations of the driven end wall in a direction perpendicular thereto with an annular node between the center of the driven end wall and the side wall when in use; an isolator operatively associated with the peripheral portion of the driven end wall to reduce damping of the displacement oscillations; an electrochemical detection system having a polymeric material that is printed onto electrical contacts of the isolator and being operable to detect the presence of a target gas in fluid that flows through the pump body; a first aperture disposed at any location in either one of the end walls (12, 13) other than at the annular node and extending through the pump body; a second aperture disposed at any location in the pump body other than the location of the first aperture and extending through the pump body; and, a valve disposed in at least one of the first aperture and second aperture; whereby: the displacement oscillations generate corresponding pressure oscillations of the fluid within the cavity of the pump body causing fluid flow through the first aperture and the second aperture when in use. a pump body having a cylindrical shape defining a cavity for containing a fluid, the cavity being formed by a side wall closed at both ends by circular end walls (12, 13), at least one of the circular end walls (12, 13) being a driven end wall having a central portion and a peripheral portion extending radially outwardly from the central portion of the driven end wall; an actuator operatively associated with the central portion of the driven end wall to cause an oscillatory motion of the driven end wall thereby generating displacement oscillations of the driven end wall in a direction perpendicular thereto with an annular node between the center of the driven end wall and the side wall when in use; an isolator operatively associated with the peripheral portion of the driven end wall to reduce damping of the displacement oscillations; an electrochemical detection system having a polymeric material that is printed onto electrical contacts of the isolator and being operable to detect the presence of a target gas in fluid that flows through the pump body; a first aperture disposed at any location in either one of the end walls (12, 13) other than at the annular node and extending through the pump body; a second aperture disposed at any location in the pump body other than the location of the first aperture and extending through the pump body; and, a valve disposed in at least one of the first aperture and second aperture; whereby: the displacement oscillations generate corresponding pressure oscillations of the fluid within the cavity of the pump body causing fluid flow through the first aperture and the second aperture when in use.