Title :
pH micro sensor with micro-fluidic liquid-junction reference electrode on-chip for cell culture applications
Author :
Kieninger, J. ; Marx, A. ; Spies, F. ; Weltin, A. ; Urban, G.A. ; Jobst, G.
Author_Institution :
Dept. of Microsyst. Eng., Univ. of Freiburg, Freiburg, Germany
Abstract :
pH micro sensors are nowadays often realized as potentiometric sensors with a metal oxide and a reference electrode. Many used or presented potentiometric pH micro sensors clearly lack in performance due to the used reference electrode. In this work, we describe a micro reference electrode with liquid-junction on chip, which is combined with iridium oxide as pH sensing electrode. The micro-reference electrode shows a defined potential independent of the chloride ion concentration in the measurement electrolyte and a low drift rate of only 4 mV/day, which can be easily further reduced by adaption of the geometry. The micro sensor has an integrated reference electrolyte volume as liquid junction to connect the electrode element (Ag/AgCl in KCl solution) with the measurement medium. The sensor especially benefits from a simple and cost-effective production and filling process. The system is intended for usage in cell culture and drug screening applications.
Keywords :
bioMEMS; biomedical engineering; cellular biophysics; chemical sensors; drugs; electrochemical electrodes; lab-on-a-chip; microfluidics; microsensors; pH measurement; potentiometers; silver; silver compounds; Ag-AgCl; cell culture applications; drug screening applications; electrode element; iridium oxide pH sensing electrode; metal oxide electrode; microfluidic liquid junction reference electrode; microreference electrode; on chip liquid junction; pH microsensor; potentiometric sensors; Chemical vapor deposition; Electrodes; Filling; Glass; Kirchhoff´s Law; Platinum; Pollution measurement; Resists; Silicon; Silver;
Conference_Titel :
Sensors, 2009 IEEE
Conference_Location :
Christchurch
Print_ISBN :
978-1-4244-4548-6
Electronic_ISBN :
1930-0395
DOI :
10.1109/ICSENS.2009.5398297