Serotonin (SER) is the important neurotransmitter and its amount in human body can affect the human life. The low level results in anxiety and carcinoid syndrome. Its high level causes crucial toxicity. Molecularly imprinted approach was used in designing a new electrochemical sensor for serotonin (SER) detection in urine samples. The sensor was prepared based on graphene quantum dots (GQDs) incorporated two-dimensional (2D) hexagonal boron nitride (2D-hBN) nanosheets. All nanomaterials' formation and properties were highlighted with scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) method, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). SER imprinted voltammetric sensor was improved in presence of 80.0 mM phenol containing 20.0 mM SER by CV. 1.0 x 10(-12)-1.0 x 10(-8)M and 2.0 x 10(-13)M were founded as the linearity range and the detection limit (LOD). SER imprinted glassy carbon electrode (GCE) was used for urine sample analysis in presence of the other competitor agents such as dopamine (DOP), tryptophan (TRY) and norepinephrine (NOR). The sensor was also investigated for stability and selectivity.