NITRILOTRIACETIC ACID LINKERS, SOLID PHASE SYNTHESIS OF NITRILOTRIACETIC ACID LINKERS AND APPLICATIONS THEREOF
Described are devices, compounds and methods for detecting an analyte in a sample. More particularly this disclosure provides SPR and LSPR sensors modified by NTA linkers for binding a ligand and/or analyte. The NTA linkers of the disclosure typically include a head (or “anchoring site”) for coupling to a surface of the SPR or LSPR sensor, a spacer, and one or more attachment sites on a distal end or ends of the spacer which couple to a ligand. The head may include a thiol for coupling the linker to a surface of the SPR or LSPR sensor. The spacer may be a carbon chain. PAG or PEG chain, or matrix material. The one or more attachment sites may be a nitrilotriacetic acid (NTA) moiety capable of chelating a transition metal ion and binding the ligand.
1 . A nitrilotriacetic acid linker having the formula:
wherein the AA group comprises a linear or branched natural or synthetic amino acid group comprising one or more amino acids;
the optional spacer comprises a linear or branched carbon chain, comprising one or more amino acids, a polymeric moiety, or any combination thereof, wherein in the absence of the spacer, the AA group is coupled to the one or more nitrilotriacetic acid (NTA) groups;
the nitrilotriacetic acid (NTA) group comprises one or more nitrilotriacetic acid functional groups;
wherein R is H, a short chain alkyl, or an NTA group;
wherein n is the number of spacers in the linker;
wherein o is the number of NTA groups in the linker; and
wherein p is the number of
moieties.
2 . The nitrilotriacetic acid linker of claim 1 , wherein the AA group comprises from one to 10 amino acids.
3 . The nitrilotriacetic acid linker of claim 1 , wherein the AA group comprises a cysteine or a methionine amino acid.
4 . The nitrilotriacetic acid linker of claim 1 , wherein the spacer comprises a carbon chain.
5 . The nitrilotriacetic acid linker of claim 1 , wherein the spacer comprises a PAG group having one or more PAG units.
6 . The nitrilotriacetic acid linker of claim 1 , wherein the spacer comprises a PEG group having one or more PEG units.
7 . The nitrilotriacetic acid linker of claim 1 , wherein n comprises from 0 to 50 spacers.
8 . The nitrilotriacetic acid linker of claim 1 , wherein o comprises from 1 to 10 NTA groups.
9 . The nitrilotriacetic acid linker of claim 1 , wherein p comprises from 1 to 10 moieties.
10 . The nitrilotriacetic acid linker of claim 1 , wherein the one or more NTA groups are configured to couple to a ligand and/or an analyte.
11 . A surface plasmon resonance (SPR) or localized surface plasmon resonance (LSPR) sensor, the sensor comprising:
(a) a substrate, wherein the substrate comprises a solid support coated with a metal layer; and
(b) a nitrilotriacetic acid (NTA) linker having the formula:
wherein the AA group comprises a linear or branched natural or synthetic amino acid group comprising one or more amino acids;
the optional spacer comprises a linear or branched carbon chain, comprising one or more amino acids, a polymeric moiety, or any combination thereof, wherein in the absence of the spacer, the AA group is coupled to the one or more nitrilotriacetic acid (NTA) groups;
the nitrilotriacetic acid (NTA) group comprises one or more nitrilotriacetic acid functional groups;
wherein R is H, a short chain alkyl, or an NTA group;
wherein n is the number of spacers in the linker;
wherein o is the number of NTA groups in the linker;
wherein p is the number of
moieties;
(c) wherein the AA group of the NTA linker is coupled to the metal layer; and
(d) wherein the one or more nitrilotriacetic acid functional groups of the linker are capable of binding to one or more ligands and/or analytes.
12 . The sensor of claim 11 , wherein the sensor comprises a substrate and a coating layer, and the AA group is covalently coupled to the coating layer.
13 . The sensor of claim 12 , wherein the substrate is selected from a group consisting of silicon substrates, glass substrates, polystyrene substrates, agarose substrates.
14 . The sensor of claim 12 , wherein the coating layer comprises a first inner coating and a second outer coating.
15 . The sensor of claim 14 , wherein the first inner coating comprises a polyelectrolyte or a poly(allylamine hydrochloride).
16 . The sensor of claim 14 , wherein the second outer coating comprises a metal coating, a gold film, a metal nanoparticle coating, or a gold nanoparticle coating.
17 . A method for detection of an analyte in a fluid using a surface plasmon resonance (SPR or LSPR) sensor, comprising:
providing an SPR or LSPR sensor comprising a surface, the surface comprising a solid support coated with a metal layer and having a nitrilotriacetic acid linker attached to the metal layer, the nitrilotriacetic acid linker having the formula:
wherein the AA group comprises a linear or branched natural or synthetic amino acid group comprising one or more amino acids;
the optional spacer comprises a linear or branched carbon chain, comprising one or more amino acids, a polymeric moiety, or any combination thereof, wherein in the absence of the spacer, the AA group is coupled to the one or more nitrilotriacetic acid (NTA) groups;
the nitrilotriacetic acid (NTA) group comprises one or more nitrilotriacetic acid functional groups;
wherein R is H, a short chain alkyl, or an NTA group;
wherein n is the number of spacers in the linker;
wherein o is the number of NTA groups in the linker;
wherein p is the number of
moieties; and
optionally one or more ligands coupled to the nitrilotriacetic acid linker;
contacting a fluid comprising an analyte with the SPR or LSPR sensor; and
measuring an optical signal to detect a change in the optical signal in response to the contacting to measure the analyte in the fluid
18 .- 66 . (canceled)