Method for fabricating a carbon nanotube array and a biochip using the self-assembly of supramolecules and staining of metal compound

Abstract

A method for fabricating a carbon nanotube (CNT) nanoarray, which includes the steps of forming a thin film of supramolecules on a substrate on which metal catalyst for CNT synthesis is deposited, inducing the self-assembly of the supramolecules by annealing to form a regular structure, selectively staining the formed regular structure with a metal compound, etching the metal compound-stained thin film to form a nanometer or smaller size pattern, forming a nanopattern of metal catalyst by using the nanopattern of supramolecules stained with the formed metal compounds, and growing carbon nanotubes (CNTs) vertically on the formed metal catalyst nanopattern. A biochip is readily fabricated by binding bioreceptor(s) to CNTs of the CNT nanoarray.

What we claim is:  
     
         1 . A method for fabricating carbon nanotubes (CNT) nanoarray, which comprises the steps of: 
 (a) forming on a substrate a thin film of a metal catalyst selected from the group consisting of Fe, Ni, Co, and alloys of said metals;    (b) forming a thin film of supramolecules inducing self-assembly on the thin film of the metal catalyst;    (c) self-assembling the supramolecules by annealing to form a regular structure;    (d) selectively staining the formed regular structure with a metal compound;    (e) removing a portion which is not stained with the metal compound by etching wherein the metal compound-stained thin film is used as a mask, thereby forming nanopattern of a supramolecule stained with the metal compound;    (f) forming nanopattern of the metal catalyst by ion-milling using the nanopattern of the supramolecule as a mask; and    (g) arranging CNTs vertically on the nanopattern of the metal catalyst supramolecules.    
     
     
         2 . The method of  claim 1 , wherein the supramolecule is a disc-shaped dendrimer, fan-shaped supramolecules or cone-shaped supramolecules.  
     
     
         3 . The method of  claim 2 , wherein the supramolecule is the compound of the following formula ( 1 ):  
       
         
           
           
               
               
           
         
       
     
     
         4 . The method of  claim 1 , wherein step (c) includes heating the supramolecules above their liquid crystal transition temperature and then cooling slowly.  
     
     
         5 . The method of  claim 1 , wherein the metal compound of the step (d) comprises ruthenium tetraoxide (RuO 4 ).  
     
     
         6 . The method of  claim 1 , which additionally comprises a step of exposing carboxyl functionality by plasma treatment of ends of the vertically arranged CNTs.  
     
     
         7 . A method of fabricating a biochip, comprising attaching to a CNT, in a CNT nanoarray fabricated according to the method of  claim 1 , a bioreceptor selected from the group consisting of proteins, peptides, amino acids, DNA, PNA, enzymatic substrates, ligands, cofactors, carbohydrates, lipids, oligonucleotides, and RNA.  
     
     
         8 . The method of  claim 7 , wherein the bioreceptor is attached to a CNT in said nanoarray by applying an electric field.  
     
     
         9 . The method of  claim 8 , wherein a charge of a polarity opposite to a net charge of the bioreceptor is applied to the CNT.  
     
     
         10 . The method of  claim 8 , wherein the bioreceptor is attached to the CNT using a binding aid.  
     
     
         11 . The method of  claim 10 , wherein the binding aid comprises a chemical substance having an aldehyde, amine or imine group attached to a terminal carbon group.  
     
     
         12 . A method for fabricating a biochip, which comprises binding to a terminal carboxyl functionality of a CNT, in a CNT nanoarray fabricated by the method of  claim 6 , a bioreceptor having an amine group(NH 2 ).  
     
     
         13 . The method of  claim 12 , which comprises using a coupling agent and a coupling aid for inducing formation of an amide bond in said binding.  
     
     
         14 . A biochip fabricated by the method of  claim 7 , in which a bioreceptor, selected from the group consisting of proteins, peptides, amino acids, DNA, PNA, enzymatic substrates, ligands, cofactors, carbohydrates, lipids, oligonucleotides, and RNA, is attached to a CNT of said CNT nanoarray.  
     
     
         15 . A method of detecting reaction between biomaterials and bioreceptors, which comprises using the biochip of  claim 14  to effect a bioreceptor/biomaterial reaction.  
     
     
         16 . A biochip fabricated by the method of  claim 12 , in which a bioreceptor, selected from the group consisting of proteins, peptides, amino acids, DNA, PNA, enzymatic substrates, ligands, cofactors, carbohydrates, lipids, oligonucleotides, and RNA, is bound to a CNT in said CNT nanoarray by an amide bond.  
     
     
         17 . A method of detecting reaction between biomaterials and bioreceptors, which comprises using the biochip of  claim 16  to effect a bioreceptor/biomaterial reaction.