Biosensor for metal analysis and speciation
View Patent ↗A biosensor for metal analysis and speciation is disclosed. The biosensor comprises an electron carrier immobilized to a surface of an electrode and a layer of an immobilized enzyme adjacent to the electrode. The immobilized enzyme comprises an enzyme having biological activity inhibited by a metal to be detected by the biosensor.
1. An apparatus for detecting a presence or absence of a metal of interest in a sample containing a plurality of metals comprising:
a biosensor comprising an electron carrier immobilized to a surface of an electrode and a layer of an immobilized enzyme adjacent to the electrode, wherein the immobilized enzyme comprises an enzyme inhibited by the metal of interest; and
at least one chelating agent selected to chelate a portion of the plurality of metals without chelating the metal of interest.
2. The apparatus of claim 1 , wherein the electron carrier is nicotinamide adenine dinucleotide or nicotinamide adenine dinucleotide phosphate.
3. The apparatus of claim 2 , wherein the immobilized enzyme is nitrate reductase.
4. The apparatus of claim 3 , wherein the nitrate reductase is crosslinked to the layer of the immobilized enzyme.
5. The apparatus of claim 2 , wherein the immobilized enzyme is inhibited by the presence of chromium in the sample.
6. The apparatus of claim 1 , wherein the electrode is a gold electrode.
7. The apparatus of claim 1 , wherein the metal of interest is chromium.
8. The apparatus of claim 1 , where in the plurality of metals is selected from the group consisting of chromium, copper, lead, cadmium, nickel, zinc, arsenic, mercury, silver, and mixtures thereof.
9. An apparatus for detecting a presence or absence of a valence state of interest of a metal of interest in a sample containing a plurality of metals comprising:
a biosensor comprising an electron carrier immobilized to a surface of an electrode and a layer of an immobilized enzyme adjacent to the electrode, wherein the immobilized enzyme comprises an enzyme inhibited by the valence state of interest of the metal of interest; and
at least one chelating agent selected to chelate a portion of the plurality of metals without chelating the valence state of interest of the metal of interest.
10. The apparatus of claim 9 , wherein the electron carrier is nicotinamide adenine dinucleotide or nicotinamide adenine dinucleotide phosphate.
11. The apparatus of claim 10 , wherein the immobilized enzyme is inhibited by the presence of chromium in the sample.
12. The apparatus of claim 9 , wherein the electrode is a gold electrode.
13. The apparatus of claim 12 , wherein the immobilized enzyme is nitrate reductase.
14. The apparatus of claim 13 , wherein the nitrate reductase is crosslinked to the layer of the immobilized enzyme.
15. The apparatus of claim 9 , wherein the valence state of interest of the metal of interest is a chromium ion.
16. The apparatus of claim 9 , where in the plurality of metals is selected from the group consisting of chromium, copper, lead, cadmium, nickel, zinc, arsenic, mercury, silver, and mixtures thereof.
17. An apparatus for detecting a presence or absence of a valence state of interest of chromium in a sample containing a plurality of metals in one or more valence states comprising:
a biosensor comprising an electron carrier immobilized to a surface of an electrode and a layer of an immobilized enzyme adjacent to the electrode, wherein the immobilized enzyme comprises an enzyme inhibited by the valence state of interest of chromium; and
at least one chelating agent selected to chelate a portion of the plurality of metals without chelating the valence state of interest of chromium.
18. The apparatus of claim 17 , wherein the electron carrier is nicotinamide adenine dinucleotide or nicotinamide adenine dinucleotide phosphate.
19. The apparatus of claim 17 , wherein the electrode is a gold electrode.
20. The apparatus of claim 19 , wherein the immobilized enzyme is nitrate reductase.