Dopaminergic neurons of the midbrain are the main source of dopamine (DA) in the mammalian central nervous system. As a neurotransmitter DA were released by dopaminergic neurons to activate or modulate downstream neuron. DA circuits in brain which composed by lots dopaminergic neurons involved in many psychological and physiological functions of brain such as cognition, reward prediction, sense of pleasure and voluntary movement. On the other way, dysfunction of dopaminergic neurons may result in several neurodegenerative disorders like Parkinson’s disease. Previous studies suggested that lose of dopaminergic neurons in the substantia nigra is responsible for dysfunction in movement in patients of Parkinson’s disease. We had developed an DA sensor and showed the sensor can detect dopamine in vitro. In this thesis we expressed the probe on mammal cell membrane to determine its activity and level of sensitivity upon DA treatment. Through this work such kind of probe may be expressed in neuron and observe the activation of DA circuits when applying different stimulations.