Method for Sensing a Substance to be Detected in a Sample

Abstract

A single-electron transistor comprising at least a substrate, a source electrode and a drain electrode formed on top of the substrate opposing to each other, and a channel arranged between the source electrode is disclosed wherein the channel is composed of ultra fine fibers. By having such a constitution, a sensor can have excellent sensitivity.

1 . A method for sensing a substance to be detected in a sample by means of a sensor at least provided with a substrate, and a channel having a source electrode and a drain electrode formed with a certain interval and opposite one another on a first insulating membrane formed on top of the substrate, the method comprising the steps of:
 composing the channel of ultra fine fibers;   forming a second insulating membrane in a portion of the substrate on an opposite side to a position where the channel is located;   forming a back gate electrode on an outer side of the second insulating membrane;   modifying the second insulating membrane by a specific substance that interacts with a substance to be detected;   dropping subsequent to a solution of the sample between the modified portion and the back gate electrode; and   evaporating a solvent of the solution.   
     
     
         2 . A method for sensing a substance to be detected in a sample by means of a sensor at least provided with a substrate, and a channel having a source electrode and a drain electrode formed with a certain interval and opposite one another on a first insulating membrane formed on top of the substrate, the method comprising the steps of:
 composing the channel of ultra fine fibers;   forming a second insulating membrane in a portion of the substrate on an opposite side to a position where the channel is located;   forming a back gate electrode on an outer side of the second insulating membrane;   modifying the second insulating membrane by a specific substance that interacts with a substance to be detected;   dropping subsequent to a solution of the sample between the modified portion and the back gate electrode; and   freezing a solvent of the solution.   
     
     
         3 . The method for sensing a substance to be detected in a sample according to  claim 1 , wherein the ultra fine fibers are carbon nanotubes. 
     
     
         4 . The method for sensing a substance to be detected in a sample according to  claim 3 , wherein a defect is introduced into the carbon nanotubes. 
     
     
         5 . The method for sensing a substance to be detected in a sample according to  claim 1 , wherein the specific substance is a biopolymer that interacts with a biopolymer substance to be detected. 
     
     
         6 . The method for sensing a substance to be detected in a sample according to  claim 5 , wherein, when the substance to be detected is an antigen or an antibody, the specific substance is an antibody or an antigen. 
     
     
         7 . The method for sensing a substance to be detected in a sample according to  claim 2 , wherein the ultra fine fibers are carbon nanotubes. 
     
     
         8 . The method for sensing a substance to be detected in a sample according to  claim 7 , wherein a defect is introduced into the carbon nanotubes.