Detection of cyanide using immobilized porphyrin and myoglobin surfaces

Abstract Copper-complexed meso-tetra(4-carboxyphenyl) porphine monoethylene diamine coupled to Traut’s reagent immobilized onto a cellulose film exhibits a broad absorbance peak in the Soret region at 418 nm. Addition of NaCN solution to the immobilized porphyrin monolayer results in a loss in absorbance at 411 nm and an increase in absorbance at 421 nm as the porphyrin cyanide complex forms. The change in absorbance is linear with the log of increasing cyanide concentration; cyanide can be detected down to 1.6 ppb levels in less than 6 s. Myoglobin immobilized onto a glass surface shows increased absorbance at 400 and 495 nm and decreased absorbance at 444 nm following exposure to NaCN solution or HCN gas. The absorbance change is linearly dependent on the NaCN concentration with detection limits at 1.5 ppb and is linearly dependent on the HCN concentration up to 10 ppm.