# US 2017/0285014 A1 · Methods for the detection of cyanide based on displacement of the glutathione ligand of glutathionylcobalamin by cyanide

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2017/0285014 A1
- Document ID: US20170285014A1
- Status: Published application
- Kind: A1
- Application number: 15/250,560
- Filed: 2016-08-29
- Published: 2017-10-05
- Earliest claimed: 2016-03-29
- Assignees: Research Cooperation Foundation of Yeungnam University
- Applicants: Research Cooperation Foundation of Yeungnam University
- Inventors: Ji-Hoe KIM
- Web page: https://patentgrep.com/patent/US20170285014A1

## CPC

- 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 21/33: using ultraviolet light (G01N21/39 takes precedence)
- G01N 21/6428: {Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" (in vivo A61B5/00; immunoassay G01N33/53)}
- G01N 21/643: {non-biological material}
- G01N 21/78: producing a change of colour
- G01N 33/84: involving inorganic compounds or pH
- G01N 2021/7786: {Fluorescence}
- 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

Provided is a method for the detection of cyanide based on displacement of the glutathione ligand of glutathionylcobalamin by cyanide. The composition for detecting cyanide (CN−) including glutathionylcobalamin (GSCbl) and a buffer has specificity in which GSCbl does not react with other anions by nucleophilic substitution, but selectively reacts with only CN− by displacement. Further, the GSH bound to the Cbl reacts with CN− by nucleophilic substitution with high efficiency to enhance sensitivity, and cyanocobalamin (CNCbl), di-cyanocobalamin (diCNCbl) and glutathione (GSH) which are byproducts generated by nucleophilic substitution reaction of CN− may be qualitatively/quantitatively detected through spectrophotometric, naked eye, and fluorometric assays, respectively.

## Claims

### Claim 1

A composition for detecting cyanide (CN−), the composition comprising glutathionylcobalamin (GSCbl) and a buffer.

### Claim 2

A spectrophotometric detection method of cyanide, the method comprising:
adding a sample including cyanide (CN−) to a buffer including glutathionylcobalamin (GSCbl) (Step 1);
reacting the cyanide (CN−) added in Step 1 with GSH by displacement through nucleophilic attack, in which GSCbl has a characteristic that glutathione (GSH) is bound to the central cobalt (Co) of cobalamin (Cbl) having a planar structure in an axial direction (Step 2); and
qualitatively or quantitatively detecting the CNCbl generated in Step 2 by a UV-Vis spectrophotometer (Step 3).

### Claim 3 (depends on 2)

The spectrophotometric detection method of claim 2, wherein the buffer of Step 1 has pH lower than pH 9.

### Claim 4

A naked eye detection method of cyanide, the method comprising:
adding a sample including cyanide (CN−) to a buffer including glutathionylcobalamin (GSCbl) (Step 1);
reacting the cyanide (CN−) added in Step 1 with GSH by displacement through nucleophilic attack in which GSCbl has a characteristic that glutathione (GSH) is bound to the central cobalt (Co) of cobalamin (Cbl) having a planar structure in an axial direction (Step 2); and
detecting di-cyanocobalamin (diCNCbl) generated in Step 2 by the naked eye by a change in color (Step 3).

### Claim 5 (depends on 4)

The naked eye detection method of claim 4, wherein the buffer of Step 1 has pH 9 or higher pH.

### Claim 6 (depends on 1)

A kit for detecting cyanide (CN−) in a water, blood or food samples comprising the composition of claim 1.

### Claim 7

A fluorometric detection method of cyanide, comprising the steps of:
adding a sample including cyanide (CN−) to a buffer including glutathionylcobalamin (GSCbl) (Step 1);
reacting the cyanide (CN−) added in Step 1 with GSH by displacement through nucleophilic attack, in which GSCbl has a characteristic that glutathione (GSH) is bound to the central cobalt (Co) of cobalamin (Cbl) having a planar structure in an axial direction (Step 2); and
qualitatively or quantitatively detecting the GSH generated in Step 2 by a fluorometric detector (Step 3).