Nucleotide detector, process for producing the same and process for morming forming fine particle membrane

Abstract

A nucleotide detector 10 includes: metal particles 12 having a size of the order of nanometers (diameter: about 6 nm) placed on a surface of a substrate 11 at high density with high precision (with spaces of about 12 nm between adjacent particles); and single-stranded DNAs (thiol DNAs) 13 having sulfur atoms at ends bonded to the gold particles 12 . The thiol DNAs 13 are placed uniformly over the entire substrate 11 at high density with high precision. Therefore, once a fluorescence-labeled single-stranded DNA is hybridized with any of the thiol DNAs 13 , high fluorescence intensity is stably obtained. This detector is therefore usable as a high-performance DNA sensor with a high SN ratio.

1 . (Deleted)  
     
     
         2 . A method for manufacturing a nucleotide detector comprising the steps of: 
 (a) arranging complex particles each including a metal particle and a protein molecule holding the metal particle on a substrate;    (b) removing the protein molecules; and    (c) bonding one of a pair of nucleotide molecules capable of conjugating with each other to each of the metal particles left on the substrate in the step (b).    
     
     
         3 . The method for manufacturing a nucleotide detector of  claim 2 , wherein the protein molecules are Dps protein or apoferritin.  
     
     
         4 . The method for manufacturing a nucleotide detector of  claim 2  or  3 , wherein the nucleotide molecules comprise a plurality of types of nucleotide molecules having different base sequences.  
     
     
         5 . (Amended) A method for producing a particulate film comprising the steps of: 
 (a) placing a substrate in a container so that a surface of the substrate is vertical to the liquid level of a liquid containing particulates filled in the container; and    (b) forming a wet film made of the particulates dispersed two-dimensionally on the surface of the substrate by raising or lowering the liquid level of the liquid.    
     
     
         6 . The method for producing a particulate film of  claim 5 , wherein the particulates have a diameter of 50 nm or less.  
     
     
         7 . The method for producing a particulate film of  claim 5  or  6 , wherein the particulates are protein.  
     
     
         8 . The method for producing a particulate film of  claim 7 , wherein the protein contains an inorganic material inside.  
     
     
         9 . The method for producing a particulate film of  claim 7  or  8 , wherein the concentration of the protein in the liquid is 10 μg/ml to 500 mg/ml.  
     
     
         10 . The method for producing a particulate film of any of  claims 7  to  9 , wherein the liquid contains an electrolyte.  
     
     
         11 . The method for producing a particulate film of any of claims  7  or  10 , wherein a liquid level raising or lowering rate of the liquid is substantially constant, and it is 10 mm/min. or less.  
     
     
         12 . The method for producing a particulate film of any of  claims 7  to  11 , wherein the liquid is allowed to flow out by gravity.  
     
     
         13 . The method for producing a particulate film of any of  claims 7  to  12 , wherein the substrate has a convex and concave pattern on a surface.