Nano-structured Platinum-Yttria Stabilized Zirconia (YSZ) composites for oxygen potentiometric sensors were directly prepared with carbon black and the precursors such as chloroplatinic acid, zirconyl nitrate and yttrium nitrate. The as-prepared Pt-YSZ composite consisted of cubic crystalline YSZ and Pt particles, and the particle sizes of Pt catalyst and YSZ electrolyte were about 25-35 and 5-10 nm, respectively. The Pt-YSZ composite electrodes exhibited excellent electrochemical performances when evaluated by EIS measurements. The introduction of the nano-structured Pt-YSZ composite into the oxygen potentiometric sensor can reduce sensor's operating temperature to be about 380 degrees C, and also can reduce sensor's response time to be about 5 s at 400 degrees C. The oxygen potentiometric sensors incorporating nano-structured Pt-YSZ composites exhibited longer lifetime than those employing pure Pt as the sensing electrodes. (C) 2011 Elsevier B.V. All rights reserved.