A sensitive electrochemical sensor based on sodium dodecyl sulfonate (SDS) functionalized graphene hybrid SnO2 nanoparticles (SDS-GN/SO2) composite was fabricated via one-pot synthesis. The SDS-GN/SnO2 nanocomposite significantly increased the redox activity of daphnetin due to the individual merit and mutual effect of SDSGN and SnO2 nanoparticles which improved the performance of the electrochemical sensor with high sensitivity. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) measurements were used for the detection of daphnetin. Under the optimal conditions, the oxidation peak currents of daphnetin increased proportionally to the concentration within the range of 0.03-1.0 mu mol L-1 and 1.0-8.0 mu mol L-1, and the limit of detection was 8.0 nmol L-1. The proposed modified electrode was highly sensitive and was successfully applied to determine daphnetin in the pharmaceutical sample with satisfactory recoveries. The as-prepared SDS-GN/SnO2/GCE electrochemical sensor offers a feasible way for designing simpler, low cost sensors based on SnO2 nanoparticles. (C) 2017 Elsevier B.V. All rights reserved.