A kind of dopamine sensor is developed with electrostatic self-assembly technique.The dopamine sensor coated wire is made of the pure platinum wire.Chitosan/tyrosinase composite film combined with electrostatic self-assembly technique and the Nafion membranes are employed to fabricate dopamine sensor.The sensor is applied to monitor the concentration of dopamine in rat caudate nucleus when selegiline hydrochloride is intraperitoneally injected into rat.The measuremeat results show that the sensor has the linear response range of 5×10-7～5×10-4mol/L with the square of the correlation coefficient 0.9961.RSD of its reproducibility is 3.43%.The trend of the dopamine concentration in rat caudate nucleus shows that the course of metabolism is related to dose of selegiline

and the time of maximum concentration is 40～45min.The selectivity

stability and repeatability of the sensor are good

and in-vivo determining results show that the sensor may be used for in-vivo monitoring dopamine experimental researoh.