Biological Sensor and a Method of the Production of Biological Sensor

Abstract

The invention is related to the field of biotechnology, specifically to the investigation of biomolecular interactions and sensing of biomolecules using a surface plasmon resonance. The biological sensor and a method of its production based on the thin films of graphene, graphene oxide, or single-walled or multi-walled carbon nanotubes are described. The technical results of the invention are a high sensitivity of the biosensor in combination with a high biospecificity; an expansion of the range of device applications; the protection of the metal film from an environmental exposure; the possibility to detect large biological objects. The proposed device and method of its production can be used for monitoring and recording of the concentration of chemical and biochemical substances and for the definition of parameters of biomolecular reactions in different industrial processes using biological materials, the invention can be also used in the pharmaceutical industry for the investigation of pharmacological properties and for the determination of a chemical composition of developing drugs, and also it can be used in processes of quality control of food products.

1 . A biological sensor comprising:
 a substrate, wherein a metal film is deposited on a surface of the substrate, wherein an intermediate binding layer with a biospecific layer adsorbed on its surface is located on an outer surface of the metal film, wherein the intermediate binding layer is composed of a thin film of graphene with a thickness of 0.3-2000 nm, or a thin film of single-walled or multi-walled carbon nanotubes with a thickness of 0.4-2000 nm, or a thin film of graphene oxide with a thickness of 0.7-2000 nm and   wherein the biospecific layer is located conformally and homogeneously on the surface of the intermediate binding layer and is adapted for a specific chemical interaction with biological molecules to be analyzed.   
     
     
         2 . The biological sensor of  claim 1 , wherein a metal film is the film made of gold, silver, copper, or aluminum with a thickness of 10-150 nm. 
     
     
         3 . The biological sensor of  claim 1 , wherein the biospecific layer comprises molecules of a binding partner of an analyte. 
     
     
         4 . The biological sensor of  claim 3 , wherein the biospecific layer additionally comprises: (i) molecules which have a high affinity to the molecules of a binding partner of an analyte and which form a chemical bond with them; or (ii) a hydrogel having immobilized therein the molecules of a binding partner of an analyte; or (iii) a hydrogel having immobilized therein both the molecules of a binding partner of an analyte and the molecules which have a high affinity to the molecules of a binding partner of an analyte and which form a chemical bond with them. 
     
     
         5 - 6 . (canceled) 
     
     
         7 . The biological sensor of  claim 4 , wherein, in (ii) or (iii), the hydrogel in the biospecific layer is comprises polysaccharides. 
     
     
         8 . The biological sensor of  claim 7 , wherein the polysaccharides, in the biospecific layer comprises agarose, alginic acid, dextran, carrageenan, starch, cellulose or derivatives thereof. 
     
     
         9 . The biological sensor of  claim 8  wherein the derivatives of dextran in the biospecific layer comprises carboxymethylated dextran. 
     
     
         10 . The biological sensor of  claim 4 , wherein the molecules which have a high affinity to the molecules of a binding partner of an analyte in (i) or (iii), the biospecific layer comprises molecules of avidin, streptavidin, and deglycosylated avidin, wherein molecules of a binding partner of an analyte are biotinylated. 
     
     
         11 . The biological sensor of  claim 3 , wherein the binding partner of an analyte is an antibody or a fragment of an antibody to an analyte; or wherein the binding partner of an analyte is a receptor of an analyte; or wherein the binding partner of an analyte is a binding partner of proteins, lipids, DNAs, RNAs, viruses, cells, bacteria, or toxins, or chemical modifications of these substances. 
     
     
         12 - 13 . (canceled) 
     
     
         14 . A method for producing the biological sensor according to  claim 1 , the method comprising the steps of:
 a) depositing a metal film on a substrate;   b) depositing an intermediate binding layer on an outer surface of the metal film;   c) depositing a biospecific layer onto a surface of the intermediate binding layer,   
       wherein a thin film of graphene with a thickness of 0.3-2000 nm, or a thin film of single-walled or multi-walled carbon nanotubes with a thickness of 0.4-2000 nm, or a thin film of graphene oxide with the thickness of 0.7-2000 nm is deposited as the intermediate binding layer on the outer surface of the metal film, and wherein the biospecific layer is adsorbed conformally and homogeneously on the surface of the intermediate binding layer due to chemical interaction forces between molecules of the intermediate binding layer and molecules of the biospecific layer, said chemical interaction being caused by stacking interaction or interaction of molecules of the biospecific layer with functional groups of graphene, single-walled or multi-walled carbon nanotubes or graphene oxide, wherein the adsorption provides creation of a large number of activation centers on the surface of the intermediate binding layer with a degree of filling of the surface by the molecules of the biospecific layer being 15-100% of the surface area of the intermediate binding layer. 
     
     
         15 . The method of  claim 14  wherein a film made of gold, silver, copper, or aluminum with a thickness of 10-150 nm is deposited as the metal film. 
     
     
         16 . The method of  claim 14 , wherein the biospecific layer comprises molecules of a binding partner of an analyte. 
     
     
         17 . The method of  claim 14 , wherein the biospecific layer additionally comprises: (i) molecules which have a high affinity to the molecules of a binding partner of an analyte and which form a chemical bond with them; or (ii) a hydrogel having immobilized therein the molecules of a binding partner of an analyte; or (iii) a hydrogel having immobilized therein both the molecules of a binding partner of an analyte and the molecules which have a high affinity to the molecules of a binding partner of an analyte and which form a chemical bond with them. 
     
     
         18 - 19 . (canceled) 
     
     
         20 . The method of  claim 14 , wherein in (ii) or (iii), the hydrogel comprises polysaccharides. 
     
     
         21 . The method of  claim 20 , wherein the polysaccharides comprises agarose, alginic acid, dextran, carrageenan, starch, cellulose or derivatives thereof. 
     
     
         22 . The method of  claim 21 , wherein the derivatives of dextran, the biospecific layer comprises carboxymethylated dextran. 
     
     
         23 . The method of  claim 14 , wherein in (i) or (iii), the molecules which have a high affinity to the molecules of a binding partner of an analyte comprise molecules of avidin, streptavidin, and deglycosylated avidin, wherein the molecules of a binding partner of an analyte are biotinylated. 
     
     
         24 . The method of  claim 14 , wherein the interaction of molecules of the biospecific layer with functional groups of graphene, single-walled or multi-walled carbon nanotubes or graphene oxide is carried out by the interaction with functional groups such as epoxy, hydroxyl, carbonyl or carboxyl groups. 
     
     
         25 . The method of  claim 16 , wherein the binding partner of an analyte is an antibody or a fragment of an antibody to an analyte; or wherein the binding partner of an analyte is a receptor of an analyte; or wherein the binding partner of an analyte is a binding partner of proteins, lipids, DNAs, RNAs, viruses, cells, bacteria, or toxins, or chemical modifications of these substances. 
     
     
         26 - 27 . (canceled)