To prepare a novel and highly sensitive electrochemical sensor for determination of thiamethoxam (a neonicotinoid insecticide), a nanohybrid material was utilized based on two-dimensional titanium carbide (Ti3C2Tx), belonging to the MXenes class, and exfoliated graphite nanoplatelets. The resulting material was characterized with different techniques, such UV–Vis, XRD, SEM, TEM and XPS. The sensor displayed a remarkable improvement in current responses for the electrochemical reduction of thiamethoxam compared to the bare glassy carbon electrode. Under optimized conditions, a calibration curve was built by differential pulse voltammetry in the range of 0.048 to 30 µmol L−1 with limit of detection of 20 nmol L−1. Recovery data from 90 to 105 % were obtained in beekeeping samples using the proposed sensor. Additionally, the sensor presented accurate and precise data when compared to chromatographic method data, and it was validated with statistical tests.