Sigma Xi Post-Doc Poster Session
February 19, 2004
Brian J. Polk,? Geraldine Mijares,? William MacCrehan,? Michael Gaitan?
We are developing CMOS compatible methods for fabricating thin-film
Ag/AgCl micro-reference electrodes. Micro-reference electrodes are needed
to make accurate voltammetric chemical and biochemical measurements with
high spatial resolution. A few target applications for these electrodes
include 1) electrochemical detection of DNA separations, 2) potentiometric
chemical sensing in microfluidic systems, and 3) electrochemical analysis
of single living cells. A major problem with many micro-sized quasi-reference
electrodes is maintaining a constant potential over a long period of time.
By combining micromachining with chemical and electrochemical surface treatments
we have successfully stabilized the potential of thin-film Ag/AgCl electrodes
to within 2 mV over a period of at least four days of continuous measurement.
We present here the fabrication and surface treatment protocols as well
as potentiometric characterization for a range of electrode sizes.
? NIST, EEEL, Semiconductor Electronics Division
? NIST, CSTL, Analytical Chemistry Division
Contact Name: Brian J. Polk
Division: Semiconductor Electronics (812)
Building: Technology, 225
Mail Stop: 8120
Sigma Xi member?: No