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.