Ion oxide silicon capacitor based pH sensing

Several biological applications involve measuring intracellular and extracellular pH values. This thesis reports a novel technique that uses the basic principles of a MOSCAP. Based on its functionality, the device is termed as iOSCAP (Ion Oxide Silicon Capacitor). As the name suggests, the device consists of an ionic layer on top of an oxidized Si wafer. The strength of the ionic solution determines the capacitance of the device, as the ionic strength modifies the work function of the ionic layer, thereby changing the surface potential of the device. The sensitivity of the device based on the results obtained is ~ 100pF/80 L/pH which is sufficient for the target applications, and the changes can be recorded using an LCR meter. In addition, the device can be used for tracking the intracellular and extracellular changes as its response time is ~ 5 ns. Light addressability has been tested but it will find more use when specific cell measurements are done. The device has been tested in the lab and can be made commercial by proper packaging and modeling.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Electrical & Computer Engr Psychology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2012

Author dc:creator

• Syed, Usman

Contributors dc:contributor

• Liu, Gang Logan

• Ion Oxide Silicon Capacitor (iOSCA
• Metal-Oxide-Silicon capacitors(MOSCAP)
• Work Function
• pH
• Capacitance
• Ionic Solution

Statement dc:rights

• Copyright 2012 Usman Syed

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/34288

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/34288