AVS 51st International Symposium
    Nanometer-scale Science and Technology Tuesday Sessions
       Session NS-TuP

Paper NS-TuP6
Electrochemically Grown Single Nanowires for Gas and Biochemical Detection

Tuesday, November 16, 2004, 4:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: C. Lee, Jet Propulsion Laboratory (JPL)
Authors: C. Lee, Jet Propulsion Laboratory (JPL)
M. Yun, Jet Propulsion Laboratory (JPL)
R.P. Vasquez, Jet Propulsion Laboratory (JPL)
N.V. Myung, University of California at Riverside
E. Menke, University of California at Irvine
R.M. Penner, University of California at Irvine
Correspondent: Click to Email
We have developed an electrochemical nanowire growth technique which allows the use of a wide variety of sensing materials such as metals, alloys, metal oxides, semiconductors, and conducting polymers. Using this technique, we have grown single 3 micron long Pd nanowires with a diameter of 75 nm. We have also grown single polypyrrole nanowires of 500 nm diameter. The Pd nanowires grown by this technique have been used to sense hydrogen gas and the polypyrrole nanowires have been used as a pH sensor. The Pd nanowire hydrogen sensor operates under ultra low power (~ 25 nW) conditions and exhibits a fast response (<300 ms) due to the small sensor volume. Our hydrogen sensors can detect hydrogen over a wide range of concentrations from 0.02 % hydrogen gas to 10 % hydrongen gas and can be used for monitoring explosive concentrations of hydrogen gas. In the case of single nanowire pH sensor, the current change observed upon the change in the conductivity of polypyrrole is 2 nA when 1 microliter of buffered solution at pH 12.45 is placed on top of the single polypyrrole nanowire sensor.