Methods for the detection of cyanide based on displacement of the glutathione ligand of glutathionylcobalamin by cyanide

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).

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).

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).