The detection of dopamine is essential for the treatment and diagnosis of depression and other diseases. In this work, cobalt phosphide nanowire arrays grown on titanium mesh (CoP NWAs/TM) are prepared by two steps of hydrothermal and phosphating, and firstly used for the detection of dopamine. The electrochemical behavior of the CoP NWAs/TM was evaluated by amperometry and differential pulse voltammetry. Amperometric analysis reveals admirable parameters in neutral PBS: (a) a working potential of 0.30 V; (b) a wide linear range (1 mu M similar to 3 mM); (c) a high sensitivity (3366 mu A.mM(-1).cm(-2)); (d) a low detection limit (3.56 x 10(-4) mM). Moreover, the interference effect of the common interfering species and the stability were investigated. Further experiments show that the sensor could be successfully used to detect dopamine in human blood serum.