Dopamine is an essential neurotransmitter for intercellular communication in the living organisms. Miniature sensors for dopamine detection, which rely on the electrochemical sensor with hybrid materials, cannot provide continuous monitoring and comes with several practical limits. High selectivity and sensitivity testified by human samples as well as low limit of detection are still challenging. This work reports the nanocomposite synthesis of yttrium oxide decorated on boron nitride (YO/BN) by a feasible sonochemical route for electrochemical detection of dopamine. Diverse microscopic and spectroscopic techniques are utilized to confirm the formation and the characteristics of the YO/BN nanocomposite. Compared to bare, YO- and BN-modified electrodes, the YO/BN modified electrode displays the superior electrochemical performance toward the detection of dopamine. Our electrochemical platform exhibits a wide linear range (0.008–241 μM), low detection limit (0.0003 µM) and high sensitivity (1.09 µA µM−1 cm−2) by the amperometric measurement. Furthermore, the proposed electrochemical sensor satisfies the clinical requirement in terms of reproducibility, selectivity, stability and recovery. The obtained results confirm that the proposed YO/BN based sensor can be used for the quantification analysis of dopamine in health management and clinical applications.