An electrochemical sensor for fast detection of wound infection based on myeloperoxidase activity

Infection can lead to severe complications during wound healing. We have developed an electrochemical sensor for fast and simple detection of wound infection based on the quantification of myeloperoxidase activity as a marker for infection. Applicability of the enzyme was confirmed with a correlation study with silver standard wound diagnostics. Significant higher enzyme activities comparing non infected and infected wound fluids were determined (P = 0.01). To eliminate supplemental substrate addition, the chlorination activity of the enzyme - the formation of hypochlorous acid (HOCl) from chloride and hydrogen peroxide - was investigated in different wound fluids and correlated with the peroxidation activity measurements. Significant activity differences were likewise obtained (P = 0.01). Based on this we constructed an electrochemical hydrogen peroxide sensor system for the quantification of chlorination activity in wound fluids. Furthermore, immobilized glucose oxidase was integrated into the system to provide hydrogen peroxide required by myeloperoxidase. Infected wound fluids were indeed identified by using the sensor system quantifying the consumption of hydrogen peroxide consumed by myeloperoxidase. Thereby, immobilized glucose oxidase was shown to produce enough hydrogen peroxide for the myeloperoxidase reaction from glucose present in wound fluids. There is a strong need for a simple but effective sensor system to determine infections in wounds. This sensor measuring hydrogen peroxide consumption could effectively identify infected wound fluids based on the myeloperoxidase activity.