Related Experiment Video
Updated: Jan 24, 2026

Highly Sensitive and Quantitative Detection of Proteins and Their Isoforms by Capillary Isoelectric Focusing Method
Published on: September 19, 2018
Highly sensitive and straightforward methods for the detection of cyanide using profluorescent glutathionylcobalamin
Younhwa Byun1, Safikur Rahman1, Sungwon Hwang1
1Department of Medical Biotechnology, Yeungnam University, Gyeongsan, 712-749, South Korea.
Abstract:
The extreme toxicity of cyanide and its continued use in various industries have raised concerns over environmental contamination and, therefore, considerable attention has given to develop facile and sensitive methods of cyanide detection. In this study, we developed highly sensitive and straightforward methods of cyanide detection using eosin-labeled glutathionylcobalamin (E-GSCbl) containing fluorescent eosin-labeled glutathione (E-GSH) as the upper axial ligand to the cobalt. E-GSH fluorescence was strongly quenched in E-GSCbl. The E-GSH ligand of E-GSCbl was replaced specifically by cyanide, showing recovery of the E-GSH fluorescence. This profluorescent property of E-GSCbl enabled detection of cyanide in aqueous solutions, yielding a lower detection limit of 10 nM (0.26 μg L-1). Moreover E-GSH exhibited strong luminescence under UV-light that was quenched in E-GSCbl, and this allowed naked-eye detection of cyanide at concentrations as low as 100 nM. This study demonstrates that profluorescent E-GSCbl is a highly sensitive cyanide chemosensor that can detect nanomolar concentrations of cyanide.
Related Concept Videos
Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
Effects of EDTA on End-Point Detection Methods
In the visual method, metal-ion indicators (metallochromic dyes), which have distinct colors in their free and complex forms, are added to the mixture to signal the titration's end point. They form stable complexes with metal ions, but these complexes are weaker than the corresponding metal–EDTA complexes. As a...
Precipitation Titration: Endpoint Detection Methods
In the Volhard method, a standard excess of AgNO3 is first added to the...
Sensitivity, Specificity, and Predicted Value
Sensitivity is the...
Sputum Studies II: Culture and Sensitivity
Sputum culture and sensitivity is a medical procedure used to diagnose bacterial infections in the respiratory tract and select the most appropriate antibiotics for treatment. This process involves analyzing sputum samples of thick and opaque secretions produced in the lungs and airways. These samples are collected from patients and then sent to the laboratory for analysis.
The test can identify various pathogens responsible for respiratory infections, including Streptococcus,...
Urine Studies II: Urine Culture and Sensitivity Test

