title: Iridium oxide pH microelectrode.
abstract: The manufacture, calibration, and signal conditioning during construction of an iridium/iridium oxide pH microsensor is described. The microsensor was designed to be used extracellularly, primarily in biofilm research. The sensing tip diameters were typically in the range of 3-15 mum. The iridium oxide was formed by potential cycling in dilute sulfuric acid. A pH profile across a denitrifying biofilm was measured as an example of an application. The higher Nernstian slope (70-80 mV/pH for fresh electrodes), increased rigidity, and restriction of the sensing tip to the outermost end of the electrode are features which make the iridium/iridium oxide pH microelectrode superior to a glass microelectrode.
authors.affiliation: National Science Foundation Research Center for interfacial Microbial Process Engineering, Montana State University, Bozeman, Montana 59717, USA.
authors.forename: P
authors.initials: P
authors.lastname: Vanhoudt
authors.forename: Z
authors.initials: Z
authors.lastname: Lewandowski
authors.forename: B
authors.initials: B
authors.lastname: Little