A disc pump system includes a pump body having a substantially cylindrical shape defining a cavity for containing a fluid, the cavity being formed by a side wall closed at both ends by substantially circular end walls, at least one of the end walls 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. The system includes an electrochemical detection system including a working electrode, a reference electrode, and an auxiliary electrode. The electrochemical detection system functions to detect the presence of a target gas in the fluid that flows through the pump body.