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p channel filed effect transistor and sensor using the same

Foreign code F110003148
File No. A111-35US
Posted date Jun 17, 2011
Country United States of America
Application number 54976404
Gazette No. 20060254910
Gazette No. 7339212
Date of filing Mar 25, 2004
Gazette Date Nov 16, 2006
Gazette Date Mar 4, 2008
International application number JP2004004196
International publication number WO2004086025
Date of international filing Mar 25, 2004
Date of international publication Oct 7, 2004
Priority data
  • P2003-082986 (Mar 25, 2003) JP
  • 2004WO-JP04196 (Mar 25, 2004) WO
Title p channel filed effect transistor and sensor using the same
Abstract (US7339212)
A p channel field effect transistor in which the sensitivity of an enzyme can be enhanced by immobilizing the enzyme directly on an FET channel surface (diamond surface), as well as a sensor including the same, is provided.
A diamond surface ( 22 ) having mixed hydrogen terminals, oxygen terminals, and amino terminals is treated under the action of glutaraldehyde OHC(CH2)3CHO ( 30 ), so that the glutaraldehyde ( 30 ) is immobilized on the diamond surface ( 22 ) having mixed hydrogen terminals, oxygen terminals, and amino terminals.
Subsequently, urease ( 29 ) is further applied thereto, so that the amino group ( 31 ) of the urease ( 29 ) is bonded to the glutaraldehyde ( 30 ).
That is, the urease ( 29 ) can be immobilized on the diamond surface ( 22 ) having mixed hydrogen terminals, oxygen terminals, and amino terminals.
When the urea concentration is increased from 10-6 M to 10-2 M, the threshold voltage shifts by about 0.1 V in the positive direction, and the sensitivity to urea concentration of 30 mV/decade is exhibited.
Scope of claims [claim1]
1. A p channel field effect transistor used as a gate comprising: a liquid electrolyte;
and
a diamond surface that serves as a channel comprising a mixture of hydrogen terminals, oxygen terminals, and amino terminals.
[claim2]
2. A sensor comprising: p channel field effect transistor according to claim 1 and exhibiting a pH sensitivity through the use of a shift of threshold voltage in the positive direction on a surface having mixed amino terminals and oxygen terminals in response to an increase in pH of a liquid electrolyte.
[claim3]
3. The sensor according to claim 2, wherein the increase in pH is 2 to 12.
[claim4]
4. The sensor according to claim 3, wherein the surface supports the immobilization of an urease and a glutaldehyde, wherein the glutaldehyde is a divalent aldehyde, wherein the shift of threshold voltage occurs in the positive direction in response to an increase in urea concentration so that the increase in urea concentration is detected by the sensor.
[claim5]
5. The sensor according to claim 2 wherein the surface supports the immobilization of an urease and a glutaldehyde, wherein the glutaldehyde is a divalent aldehyde, wherein the shift of threshold voltage occurs in the positive direction in response to an increase in urea concentration so that the increase in urea concentration is detected by the sensor.
[claim6]
6. The sensor according to claim 5, wherein the increase in urea concentration is 10-6 M to 10-2 M.
[claim7]
7. A sensor comprising: a diamond surface that serves as a channel comprising a mixture of hydrogen terminals and amino terminals;
and
a p channel field effect transistor that serves as a gate comprising a liquid electrolyte, and that allows a shift of threshold voltage in a positive direction on the diamond surface in response to an increase in pH of the liquid electrolyte in the p channel field effect transistor so that the increase in pH is detected by the sensor.
[claim8]
8. The sensor according to claim 7, wherein the diamond surface supports the immobilization of an urease and a glutaldehyde, wherein the glutaldehyde is a divalent aldehyde, wherein the shift of threshold voltage occurs in the positive direction in response to an increase in urea concentration so that the increase in urea concentration is detected by the sensor.
[claim9]
9. The sensor according to claim 7, wherein the diamond surface is a polycrystalline diamond surface, a nanocrystalline diamond surface, or a monocrystalline diamond surface.
  • Inventor, and Inventor/Applicant
  • KAWARADA HIROSHI
  • JAPAN SCIENCE AND TECHNOLOGY AGENCY
IPC(International Patent Classification)
Reference ( R and D project ) CREST Function Evolution of Materials and Devices based on Electron/Photon Related Phenomena AREA
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