We propose an electrochemical sensor using $$\hbox {NiFe}_{2}\hbox {O}_{4}$$ nanoparticles-decorated activated carbon (AC) nanocomposite for selective detection of dopamine (DA) in the presence of uric acid (UA) and ascorbic acid (AA). The nanocomposite was prepared by a simple hydrothermal method and the characterization was done using transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffraction (XRD) patterns and Fourier transform infrared (FTIR) spectroscopy. The $$\hbox {NiFe}_{2}\hbox {O}_{4}$$ -AC-modified glassy carbon electrode (GCE) showed excellent electrocatalytic activity towards DA compared to $$\hbox {NiFe}_{2}\hbox {O}_{4}$$ /GCE and AC/GCE. This is attributed to the synergistic action and the large surface area of the nanocomposite. Differential pulse voltammetry (DPV) was employed for the detection of DA wherein the detection limit of $$0.4\,\upmu \hbox {M}$$ along with a linear range of $$5\,\upmu \hbox {M}$$ to $$100\,\upmu \hbox {M}$$ was deduced. The selective detection of DA in presence of AA and UA was demonstrated. The advantages of the present sensor include the ease of preparation of the nanocomposite, low detection limit, remarkable selectivity, good reproducibility and stability. $$\hbox {NiFe}_{2}\hbox {O}{4}$$ -AC nanocomposite was prepared by a simple hydrothermal method. The nanocomposite exhibited enhanced activity towards electro-oxidation of dopamine and excellent selectivity in the presence of uric acid (UA) and ascorbic acid (AA).