Advances on chip inside a cell for monitoring physiological cell parameters
Abstract/Contents
- Abstract
- Continuous monitoring of physiological parameters inside a living cell will lead to major advances in understanding of biology and complex diseases, such as cancer. It also enables us to develop new medical diagnostics and therapeutics. Here we propose a technique to measure the pH level inside a cell using a wireless implantable passive sensor, which consists of capacitive and inductive components. Even a slight change of cellular pH level can reveal substantial information about the health of a cell. Only a highly sensitive pH sensor can detect this slight variation. Building such a wireless implantable sensor platform is the main goal of this thesis. Our designed and fabricated pH sensor is basically an extended gate ISFET (Ion Sensitive Field Effect Transistor) structure. It is compatible with CMOS (Complementary Metal Oxide Silicon) fabrication processes and can be miniaturized as an implantable device. To fully understand the parameters that give rise to high pH sensitivity, we have investigated the effect of solution molecular size on enhancing the sensitivity of this type of sensor. Our simulation and experimental results show that buffered solutions with larger counter ion size can induce significantly higher hydrogen ion activity at the sensor surface. The larger buffer counter ion size results in higher externally measured sensitivity, which even exceeds the Nernst limit (59mV/pH). For each pH buffer solution there is a specific size of the counter ion, which is necessary to achieve this high sensitivity. In addition, progress in nanofabrication and wireless communication has opened up the potential of making our wireless chip small enough that it can be wholly inserted into a cell. To investigate how the chip could be internalized into the cell and how the chip would affect cell physiology, we designed and fabricated a series of 3D multilayer structures with different sizes as a potential RFID (Radio Frequency IDenentification) cell tracker. Our experiments show that the chips with smaller sizes than 21 µm × 9 µm × 1.5 µm can be easily internalized by various types of living cells, such as macrophages, cancer cells, and normal/healthy cells. The incubated cells with internalized chips stayed alive during the 7 days of monitoring. Also, we observed successful cell division from these incubated cells. These results are the first steps towards long-term, wireless, intracellular physiologic monitoring.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2016 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Baghbani Parizi, Kokab |
|---|---|
| Associated with | Stanford University, Department of Electrical Engineering. |
| Primary advisor | Wong, Hon-Sum Philip, 1959- |
| Thesis advisor | Wong, Hon-Sum Philip, 1959- |
| Thesis advisor | McConnell, Michael |
| Thesis advisor | Poon, Ada Shuk Yan |
| Advisor | McConnell, Michael |
| Advisor | Poon, Ada Shuk Yan |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Kokab Baghbani Parizi. |
|---|---|
| Note | Submitted to the Department of Electrical Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2016. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2016 by Kokab Baghbani Parizi
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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