Development and fabrication of Ion-sensitive Field Effect Transistor (ISFET) for pH detection, DNA immobilization and hybridization

The fabrication of ion sensitive field-effect transistor (ISFET) using silicon nitride (Si3N4) as the sensing membrane is reported. The operation of ISFET is based on the surface charge adsorption of the membrane-solution interface. This thesis describes the design, fabrication and characterization...

Full description

Saved in:

Bibliographic Details
Main Author:	Chong, Soon Weng
Format:	Thesis
Language:	English
Subjects:	Ion concentration Ion Sensitive Field Effect Transistor (ISFET) Ion detection DNA immobilization ISFET device pH detection Label free
Online Access:	http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/31211/1/Page%201-24.pdf http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/31211/2/Full%20text.pdf
Tags:	Add Tag No Tags, Be the first to tag this record!

id	my-unimap-31211
record_format	uketd_dc
spelling	my-unimap-312112014-01-15T02:02:12Z Development and fabrication of Ion-sensitive Field Effect Transistor (ISFET) for pH detection, DNA immobilization and hybridization Chong, Soon Weng The fabrication of ion sensitive field-effect transistor (ISFET) using silicon nitride (Si3N4) as the sensing membrane is reported. The operation of ISFET is based on the surface charge adsorption of the membrane-solution interface. This thesis describes the design, fabrication and characterization of ISFET for pH detection, DNA immobilization and hybridization. Four photomasks were utilized in the fabrication process to create the ISFET device. The fabricated ISFET device was first brought to morphological characterization before proceeding with the electrical characterization. For the analysis of ISFET in test solution, the Ag/AgCl electrode was used as the reference electrode immersed in different values pH buffer. The results were generated by LabTracer 2.0 measurement system which shows that IV characteristic of ISFET devices gives linear response. The acidic pH buffers contains H+ ions which attract more electron into the conduction channel lowering the channel resistance giving higher value of current flow. While the alkaline pH buffers contains OH- ions which pushed away the electrons from the conduction channel generating more positive holes increasing the channel resistance, thus giving a lower value of current flow. When tested with phosphate buffer solution (PBS), the curves show a decreasing trend of drain current with decreasing concentration of the PBS. It was found that the device has a sensitivity of 43.13 mV/pH. The ISFET device has undergo DNA processes after the electrical characterization with pH and PBS. The DNA immobilization and hybridization processes were detected through a drop in the drain current of the device. Prior to DNA immobilization, the silicon nitride surface was chemically modified to enable the ISFET sensing membrane for DNA probes coupling. It was also observed that with decreasing concentration of DNA complimentary targets in the hybridization process has contributed to the decreasing drain current detected. As a conclusion, the silicon nitride ISFET is a flexible device which can be used to detect pH as well as to perform DNA immobilization and hybridization. Universiti Malaysia Perlis (UniMAP) 2013 Thesis en http://dspace.unimap.edu.my:80/dspace/handle/123456789/31211 http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/31211/1/Page%201-24.pdf 2efb235da6a1a956d2bddb2d218ac244 http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/31211/2/Full%20text.pdf 491de6caa3bb9d881b118bc153f9b23d http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/31211/3/license.txt 8a4605be74aa9ea9d79846c1fba20a33 Ion concentration Ion Sensitive Field Effect Transistor (ISFET) Ion detection DNA immobilization ISFET device pH detection Label free Institute of Nanoelectronic Engineering
institution	Universiti Malaysia Perlis
collection	UniMAP Institutional Repository
language	English
topic	Ion concentration Ion Sensitive Field Effect Transistor (ISFET) Ion detection DNA immobilization ISFET device pH detection Label free
spellingShingle	Ion concentration Ion Sensitive Field Effect Transistor (ISFET) Ion detection DNA immobilization ISFET device pH detection Label free Chong, Soon Weng Development and fabrication of Ion-sensitive Field Effect Transistor (ISFET) for pH detection, DNA immobilization and hybridization
description	The fabrication of ion sensitive field-effect transistor (ISFET) using silicon nitride (Si3N4) as the sensing membrane is reported. The operation of ISFET is based on the surface charge adsorption of the membrane-solution interface. This thesis describes the design, fabrication and characterization of ISFET for pH detection, DNA immobilization and hybridization. Four photomasks were utilized in the fabrication process to create the ISFET device. The fabricated ISFET device was first brought to morphological characterization before proceeding with the electrical characterization. For the analysis of ISFET in test solution, the Ag/AgCl electrode was used as the reference electrode immersed in different values pH buffer. The results were generated by LabTracer 2.0 measurement system which shows that IV characteristic of ISFET devices gives linear response. The acidic pH buffers contains H+ ions which attract more electron into the conduction channel lowering the channel resistance giving higher value of current flow. While the alkaline pH buffers contains OH- ions which pushed away the electrons from the conduction channel generating more positive holes increasing the channel resistance, thus giving a lower value of current flow. When tested with phosphate buffer solution (PBS), the curves show a decreasing trend of drain current with decreasing concentration of the PBS. It was found that the device has a sensitivity of 43.13 mV/pH. The ISFET device has undergo DNA processes after the electrical characterization with pH and PBS. The DNA immobilization and hybridization processes were detected through a drop in the drain current of the device. Prior to DNA immobilization, the silicon nitride surface was chemically modified to enable the ISFET sensing membrane for DNA probes coupling. It was also observed that with decreasing concentration of DNA complimentary targets in the hybridization process has contributed to the decreasing drain current detected. As a conclusion, the silicon nitride ISFET is a flexible device which can be used to detect pH as well as to perform DNA immobilization and hybridization.
format	Thesis
author	Chong, Soon Weng
author_facet	Chong, Soon Weng
author_sort	Chong, Soon Weng
title	Development and fabrication of Ion-sensitive Field Effect Transistor (ISFET) for pH detection, DNA immobilization and hybridization
title_short	Development and fabrication of Ion-sensitive Field Effect Transistor (ISFET) for pH detection, DNA immobilization and hybridization
title_full	Development and fabrication of Ion-sensitive Field Effect Transistor (ISFET) for pH detection, DNA immobilization and hybridization
title_fullStr	Development and fabrication of Ion-sensitive Field Effect Transistor (ISFET) for pH detection, DNA immobilization and hybridization
title_full_unstemmed	Development and fabrication of Ion-sensitive Field Effect Transistor (ISFET) for pH detection, DNA immobilization and hybridization
title_sort	development and fabrication of ion-sensitive field effect transistor (isfet) for ph detection, dna immobilization and hybridization
granting_institution	Universiti Malaysia Perlis (UniMAP)
granting_department	Institute of Nanoelectronic Engineering
url	http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/31211/1/Page%201-24.pdf http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/31211/2/Full%20text.pdf
_version_	1747836784734109696

Development and fabrication of Ion-sensitive Field Effect Transistor (ISFET) for pH detection, DNA immobilization and hybridization

Similar Items