Development of porphyrins based sensors to measure the biological damage of carbon monoxide exposure

The oxygen transport in blood is threatened by the presence of carbon monoxide. CO indeed permanently replaces the oxygen molecule in the hemoglobin making this last no more effective as oxygen carrier. This mechanism is ruled by the properties of a particular metalloporphyrin (heme) for which the binding energy with CO is about 250 times higher than that towards O₂. In this paper, a sensor system based on the properties of metallaporphyrins with a colorimetric read-out is illustrated. This system is shown to be sensitive both to the concentration of CO and to the exposure time giving rise to the evaluation of the biological damage of carbon monoxide. Results shown a good accuracy of the carboxy-hemoglobin (HbCO) percentage, calculated with a standard reference model, achieving a standard error of 1%. This value is well below the amount of HbCO known to produce either acute or chronic effects on human beings.