Device for Detecting Methanol Concentration and the Method Thereof

• US 20090120808A1
• Filed: 10/31/2007
• Published: 05/14/2009
• Est. Priority Date: 06/20/2007
• Status: Abandoned Application

• Current Assignee: Development Center for Biotechnology
• Original Assignee: Development Center for Biotechnology
• Inventors: Wu, Hung-Chang, Chien, Jui-Lung, Chen, Chien-Hsiao, Pearl Lin, Hsiu-Ping
• Application Number:
  US11/932,650
• Publication Number:
  US 20090120808A1
• Time in Patent Office: Days
• US Class Current: 205/777.500
• CPC Class Codes: C12Q 1/26 involving oxidoreductase
• CPC Class Codes: C12Q 1/32 involving dehydrogenase
• CPC Class Codes: G01N 33/146 containing alcohol
• CPC Class Codes: G01N 33/98 involving alcohol, e.g. ethanol in breath

Abstract

A device for detecting methanol concentration in an alcohol-containing solution is disclosed. The device implements an electrochemical bio-detector based on a two-enzyme system to quickly, easily and accurately measure methanol concentration in an alcohol-containing solution at a relatively low cost. A method for detecting methanol concentration in a sample using the same device is also disclosed.

Claims

1. A method for measuring methanol concentration in an alcohol-containing solution, comprising:

a) oxidizing the methanol in the solution to formaldehyde with an Alcohol Oxidase (AOX);

b) oxidizing, in the presence of NAD+, said formaldehyde to formic acid with a

Formaldehyde Dehydrogenase (FDH) while reducing said NAD+ to NADH;

c) reacting said NADH with an electron mediator to oxidize said NADH to NAD+

d) generating an oxidation current by having said electron mediator release electrons after auto-oxidation; and

e) measuring the value of said oxidation current and plugging said value in a pre-established linear equation for methanol concentration and current value to determine methanol concentration in said solution.

2. The method of claim 1, wherein said electron mediator is selected from a group consisting of:

Meldola Blue (MB, 8-dimethylamino-2,3-benzophenoxazine), Prussian Blue (potassium hexacyanoferrate), dichlorophenolindophenol, p-benzoquinone, o-phenylenediamine, 3,4-dihydroxybenzaldehyde and the mixture thereof.

3. The method of claim 1, wherein the enzyme activity ratio between said AOX and said FDH ranges from 1:

0.1 to 1;

20.

4. A methanol detecting device for the detection of methanol concentration in an alcohol-containing solution, comprising:

a substrate having a reference electrode and a working electrode provided thereon, said working electrode being separate from said reference electrode and having a working area comprising an Alcohol Oxidase (AOX), a Formaldehyde Dehydrogenase (FDH), and an electron mediator.

5. The methanol detecting device of claim 4, wherein said electron mediator is selected from a group consisting of:

Meldola Blue (MB, 8-dimethylamino-2,3-benzophenoxazine), Prussian Blue (potassium hexacyanoferrate), dichlorophenolindophenol, p-benzoquinone, o-phenylenediamine, 3,4-dihydroxybenzaldehyde and the mixture thereof.

6. The methanol detecting device of claim 5, wherein said working area of said working electrode further comprises Reinecke salt.

7. The methanol detecting device of claim 6, wherein said electron mediator in said working area is Meldola Blue that forms a complex compound with said Reinecke salt, and the weight ratio between said Meldola Blue and said Reinecke salt is approximately 1:

1.

8. The methanol detecting device of claim 7, wherein said working area of said working electrode further comprises carbon gel.

9. The methanol detecting device of claim 8, wherein the weight ratio between said carbon gel and said complex compound ranges from 1:

0.2 to 1;

10.

10. The methanol detecting device of claim 4, wherein said device further comprises an active region provided on said substrate and separated from said reference electrode and said working electrode, wherein said active region comprises NAD+.

11. The methanol detecting device of claim 10, wherein said active region is provided in proximity to said working area of said working electrode.

12. The methanol detecting device of claim 4, wherein the enzyme activity ratio between said AOX and said FDH ranges from 1:

0.1 to 1;

20.

13. A method for measuring methanol concentration in a sample by using a methanol detecting device comprising a substrate having a reference electrode and a working electrode provided thereon, said working electrode being separated from said reference electrode and having a working area comprising an Alcohol Oxidase (AOX), a Formaldehyde Dehydrogenase (FDH), and an electron mediator, said working electrode and said reference electrode each connected to a corresponding terminal of a potentiostat, the method comprising:

a) measuring an initial current value (I_i) by contacting said methanol-detecting device with an initial electrolyte solution;

b) adding a predetermined amount of said sample to said initial electrolyte solution and, measuring a final current value (I_f) in the presence of NAD+;

c) calculating a current difference (Δ

I) between said initial current value and said final current value (I_i−

I_f); and

d) determining methanol concentration in said sample by plugging said current difference (Δ

I) in a pre-established linear equation for current difference and methanol concentration.

14. The method of claim 13, wherein said methanol detecting device further comprises an active region provided on said substrate and separated from said reference electrode and working electrode, said active region comprising NAD+.

15. The method of claim 13, wherein said pre-established linear equation is established by using said methanol detecting device to detect different solutions of known methanol concentration.

16. The method of claim 13, wherein said pre-established linear equation is valid when the methanol concentration ranges from 0 to 300 mg/L.

17. The method of claim 13, wherein said step c) further comprises:

calculating a current difference (Δ

I) by subtracting said final current value and a noise value of ethanol (I_e) from said initial current value (I_i−

I_f−

I_e).