A nanocomposite material with novel electrochemical properties was synthesized by immersing a platinum wire into the dense zone of the 1-2% CH4/H-2 plasma in a microwave chemical vapor deposition reactor. Raman analysis of the deposit indicated the presence of nanocrystalline diamond, graphite, and amorphous sp(3) carbon. Notably, the characteristic broad shoulder between 1350 and 1550 cm(-1) attributable to amorphous sp(2) carbon was absent. Growth of freestanding submicrometer-thick whiskers containing diamond and graphite nanocomposite was observed. The nanocomposite material, without any prior surface pretreatment, showed high reversibility (DeltaE(p) <100 mV) for dopamine redox reactions in 0.1 M KCl solution. (C) 2002 The Electrochemical Society.