A SILICON RECORDING PROBE WITH INTEGRATED AG/AGCL REFERENCE ELECTRODE FOR IN-SITU PH SENSING

This paper presents a silicon recording probe with integrated in-situ Ag/AgCl reference electrode (ISA/ARE) for simultaneous pH sensing and electrophysiology recordings for the application neuroscience. The preparation of in-situ silver layer and its chlorination are realized by a constant current electrochemical plating method. The repeatable Ag/AgCl layer with stable potential has been verified by X-ray diffraction and electrochemical measurements. Meanwhile, the pH sensitivity of the combination of Iridium oxide (IrOx) electrodes and ISA/ARE is 54.7mV/pH. The area of ISA/ARE is only 7000 mu m(2), which is highly compatible with the preparation process of silicon probes, and is suitable for integration into the front of micro shanks as an in-situ detection reference. In short, the unique fabrication method to realize miniaturized and integrated in-situ reference electrode is of great significance to biosensors.