WORKING WIRE FOR A CONTINUOUS BIOLOGICAL SENSOR WITH AN ENZYME IMMOBILIZATION NETWORK
A working wire for a continuous biological sensor is disclosed and includes a substrate having a conductive surface and an enzyme layer formed on the conductive surface. The enzyme layer includes enzymes, an immobilization matrix and a polymeric crosslinking agent that crosslinks the enzymes and the immobilization matrix creating an enzyme immobilization network. A protective layer is included over the enzyme layer. A method for making the working wire for a continuous biological sensor is disclosed and includes combining an enzyme with a solvent creating an enzyme mixture. An immobilization matrix is mixed with the enzyme mixture. After the mixing, a polymeric crosslinking agent is combined with the enzyme mixture and the immobilization matrix creating a crosslinked mixture. The crosslinked mixture is allowed to stabilize. The stabilized crosslinked mixture is applied to the working wire, and the applied mixture is cured on the working wire.
1 . A working wire for a continuous biological sensor, comprising:
a substrate having a conductive surface;
an enzyme layer on the conductive surface comprising:
enzymes;
an immobilization matrix; and
a polymeric crosslinking agent crosslinking the enzymes and the immobilization matrix creating an enzyme immobilization network; and
a protective layer over the enzyme layer.
2 . The working wire according to claim 1 , further comprising a non-polymeric crosslinking agent in the enzyme immobilization network crosslinking the enzymes and the immobilization matrix.
3 . The working wire according to claim 2 , wherein the non-polymeric crosslinking agent is selected from glutaraldehyde, polyfunctional aziridine, bifunctional carbodiimide, dicyclohexyl carbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, N-hydroxysulfosuccinimide, ethylene glycol bis(succinimidyl succinate) (EGS), ethylene glycol bis(sulfosuccinimidyl succinate) (SEGS), tris-(succinimidyl) aminotriacetate (TSAT), dimethyl pimelimidate (DMP), dimethyl suberimidate (DMS), 1,5-difluoro-2,4-dinitrobenzene (DFDNB), dimethyl 3,3′-dithiobispropionimidate (DTBP), NHS-Phosphine, NHS-PEG-azide, NHS-azide, or combinations thereof.
4 . The working wire according to claim 2 , wherein the polymeric crosslinking agent and the non-polymeric crosslinking agent is a combination of polyethylene glycol (PEG) dialdehyde and glutaraldehyde.
5 . The working wire according to claim 1 , wherein the polymeric crosslinking agent is selected from polyethylene glycol (PEG) dialdehyde, bifunctional PEG carbodiimide, PEGylated bis(sulfosuccinimidyl)suberate, or combinations thereof.
6 . The working wire according to claim 1 , wherein the immobilization matrix is a polymer selected from polyurethane (PU), polyacrylic acid, polyacrylamide, polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), or polyvinyl alcohol (PA) and its copolymers, or copolymers of N-(2-hydroxypropyl)-methacrylamide, polydimethylsiloxane (PDMS), polyamides, polyacrylates, polyethylene, polycarbonates, or combinations thereof.
7 . The working wire according to claim 1 , wherein the immobilization matrix is a protein selected from a bovine serum albumin (BSA), human serum albumin (HSA), carboxymethyl cellulose (CMC), collagen, or combinations thereof.
8 . The working wire according to claim 1 , wherein the enzymes are glucose oxidase (GOx).
9 . The working wire according to claim 1 , wherein the protective layer is a glucose limiting layer.
10 . A method of making a working wire for a continuous biological sensor, comprising:
combining an enzyme with a solvent creating an enzyme mixture;
mixing an immobilization matrix with the enzyme mixture;
after the mixing, combining a polymeric crosslinking agent with the enzyme mixture and the immobilization matrix creating a crosslinked mixture;
allowing the crosslinked mixture to stabilize;
applying the stabilized crosslinked mixture to the working wire; and
curing the applied mixture on the working wire.
11 . The method according to claim 10 , further comprising:
after the mixing, combining a non-polymeric crosslinking agent with the enzyme mixture and the immobilization matrix creating a crosslinked mixture.
12 . The method according to claim 11 , wherein the non-polymeric crosslinking agent is selected from glutaraldehyde (GA), polyfunctional aziridine, bifunctional carbodiimide, dicyclohexyl carbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, N-hydroxysulfosuccinimide, ethylene glycol bis(succinimidyl succinate) (EGS), ethylene glycol bis(sulfosuccinimidyl succinate) (SEGS), tris-(succinimidyl) aminotriacetate (TSAT), dimethyl pimelimidate (DMP), dimethyl suberimidate (DMS), 1,5-difluoro-2,4-dinitrobenzene (DFDNB), dimethyl 3,3′-dithiobispropionimidate (DTBP), NHS-Phosphine, NHS-PEG-azide, NHS-azide, or combinations thereof.
13 . The method according to claim 11 , wherein the polymeric crosslinking agent and the non-polymeric crosslinking agent is a combination of polyethylene glycol (PEG) dialdehyde and glutaraldehyde.
14 . The method according to claim 10 , wherein the polymeric crosslinking agent is selected from polyethylene glycol (PEG) dialdehyde, bifunctional PEG carbodiimide, PEGylated bis(sulfosuccinimidyl)suberate, or combinations thereof.
15 . The method according to claim 10 , wherein the immobilization matrix is a polymer selected from polyurethane (PU), polyacrylic acid, polyacrylamide, polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), or polyvinyl alcohol (PA) and its copolymers, or copolymers of N-(2-hydroxypropyl)-methacrylamide, polydimethylsiloxane (PDMS), polyamides, polyacrylates, polyethylene, polycarbonates, or combinations thereof.
16 . The method according to claim 10 , wherein the immobilization matrix is a protein selected from a bovine serum albumin (BSA), human serum albumin (HSA), carboxymethyl cellulose (CMC), collagen, or combinations thereof.
17 . The method according to claim 10 , wherein the mixing comprises high shear mixing.
18 . The method according to claim 10 , wherein the enzymes are glucose oxidase (GOx).
19 . The method according to claim 10 , wherein the continuous biological sensor has a first measured electrical enzyme sensitivity prior to gas sterilization, a second measured electrical enzyme sensitivity after the gas sterilization, and the second measured electrical enzyme sensitivity is greater than the first measured electrical enzyme sensitivity.
20 . The method according to claim 19 , wherein the gas sterilization is by ethylene oxide (EtO) sterilization.