A novel self-assembly modified carbon paste electrode based on ethylenediamine and graphene oxide was proposed as a highly sensitive electrochemical sensor for detection of malachite green. The manufacturing operation of the recommended sensor was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The electrochemical response of malachite green at this sensor was investigated in detail and a new electroanalytical method was erected with high sensitivity and selectivity. The proposed method exhibited good linearity for malachite green over the range from 8.0 × 10−9 mol L−1 to 8.0 × 10−7 mol L−1 with the detection limit of 5 × 10−9 mol L−1 (S/N = 3) by differential pulse voltammetry under optimum conditions. Finally, the practical application was proven by spiking malachite green standards in lake water with recoveries ranging from 98.80% to 101.10%, showing a satisfactory result.
