# US 10,246,732 B2 · Stabilized test strip for the detection of hydrogen peroxide

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- Number: US 10,246,732 B2
- Document ID: US10246732B2
- Status: Granted
- Kind: B2
- Application number: 15/340,229
- Filed: 2016-11-01
- Published: 2018-05-03
- Granted: 2019-04-02
- Earliest claimed: 2016-11-01
- Assignees: Precision Laboratories, Inc.
- Applicants: Precision Laboratories, Inc.
- Inventors: Eva Hrboticka
- Web page: https://patentgrep.com/patent/US10246732B2

## CPC

- C12Q 1/28: involving peroxidase
- C12Y 111/01007: Peroxidase (1.11.1.7), i.e. horseradish-peroxidase
- G01N 33/227: {Explosives, e.g. combustive properties thereof}
- G01N 33/52: Use of compounds or compositions for colorimetric, spectrophotometric or fluorometric investigation, e.g. use of reagent paper {and including single- and multilayer analytical elements (immunological elements G01N33/54386; involving labelled immunochemicals G01N33/58; for haemoglobin or occult blood G01N33/72)}
- G01N 2021/7759: {Dipstick; Test strip}
- G01N 2333/908: acting on hydrogen peroxide as acceptor (1.11)
- C12Q: MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS (immunoassay G01N33/53); COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
- C12Y: ENZYMES
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

A colorimetric dry-reagent test strip for direct detection of the presence of hydrogen peroxide in strongly acidic solutions without the necessity of a pH neutralization step comprises a chromogen responsive to hydrogen peroxide, an enzyme peroxidase catalyst and at least one complexing agent chosen to protect an active site of the catalyst for an amount of time sufficient to allow for the catalytic oxidation of the chromogen. The test strip has particular value in the determination of peroxide-based explosive compounds, such as hexamethylene triperoxide diamine (HMTD) or triacetone triperoxide (TATP), which require a treatment with a strong organic acid to release the hydrogen peroxide to be detected, and typically requires neutralization of the acid before a conventional test strip can be employed. The invention dispenses with the need for such a neutralization step.

## Claims

### Claim 1

A colorimetric dry-reagent test strip for direct detection of the presence of hydrogen peroxide in strongly acidic solutions without the necessity of a neutralization step, consisting essentially of a chromogen responsive to hydrogen peroxide, an enzyme peroxidase catalyst and at least one complexing agent at a concentration that effectively protects an active site of the catalyst for an amount of time sufficient to allow for the catalytic oxidation of the chromogen when contacted with hydrogen peroxide-containing solutions having a pH in the range of 0 to 1, wherein the components are in a dry form on a carrier.

### Claim 2 (depends on 1)

The test strip of claim 1, wherein the enzyme peroxidase catalyst is horseradish peroxidase having both acidic and basic isoenzymes.

### Claim 3 (depends on 1)

The test strip of claim 1, wherein the at least one complexing agent is chosen from the group consisting of polycarboxylic and polyaminopolycarboxylic compounds.

### Claim 4 (depends on 3)

The test strip of claim 3, wherein the polycarboxylic and polyaminopolycarboxylic compounds have three to six carboxylic groups.

### Claim 5 (depends on 1)

The test strip of claim 1 including two complexing agents.

### Claim 6 (depends on 1)

The test strip of claim 1 wherein the dry form components are located in a carrier matrix.

### Claim 7 (depends on 6)

The test strip of claim 6 wherein the carrier matrix is mounted to a support.

### Claim 8 (depends on 1)

A test kit for detecting a peroxide-based explosive compound, comprising the test strip of claim 1, a solvent for the explosive compound and a mineral acid of pH 0-1 for the degradation of the explosive compound to release hydrogen peroxide.

### Claim 9 (depends on 8)

The test kit of claim 8 further including a vial for receiving a sample of the explosive compound to be tested, the solvent and the mineral acid, the test strip being constructed and dimensioned to be insertable into the vial.

### Claim 10 (depends on 9)

The test kit of claim 9 wherein the test strip is mounted to a supporting handle.