Carbon nanotube-supported gallium (Ga/CNT) was synthesized and characterized with energy dispersive X-ray scanning electron microscopy, temperature-programmed reduction, temperature-programmed oxidation, and temperature-programmed desorption methods. Characterization results revealed successful preparation of Ga/ CNT. Electrochemical measurements were performed by cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy. The Ga/CNT-based cysteine sensor had a linear response within the range of 0-200 mu M with current sensitivity of 0.0081 mu A/mu M (114 mu A/mM cm(2)), low detection limit of 0.05 mu M, and signal-to-noise ratio of 3. Interference studies revealed that (Ga/CNT)@glassy carbon electrode was not affected by interfering species. Thus, Ga/CNT is a promising cysteine sensor.