In the current research work, the authors report the synthesis of ZnMn2O4 microspheres and G@ZnMn2O4 with a facile hydrothermal process followed by calcination. The as-synthesized materials have been used as a cost-effective strategy for the electrochemical detection of As(III). The composites are characterized for structural and morphological advances using X-ray diffraction (XRD), Scanning electron microscopy EDS, High-resolution transmission electron microscopy (HRTEM), Raman Spectroscopy and X-ray photoelectron spectroscopy (XPS). The ZnMn2O4 microspheres and G@ZnMn2O4 showed excellent electrocatalytic activity towards the reduction of As(III). The G@ZnMn2O4 modified electrode attained a sensitivity of 12.528μAppb−1cm−2 with a lower detection limit (LOD) of 0.87 ppb within the range of 0.33 ppb–5.61 ppb.