Oxidative stress as a result of reactive oxygen species (ROS) production is a hallmark of many disorders including atherosclerosis, alzheimer’s disorder and cancer. For example circulating reactive oxygen metabolites are the major cause of lipid oxidation, cellular damage, inflammation, and the accumulation of lipid-loaded macrophages which are the key mediators in developing atherosclerosis. Routine monitoring of oxidative stress has the potential to impact early diagnosis and timely initiation of appropriate treatment for ROS associated diseases. Moreover, circulating reactive oxygen metabolites such as hydroperoxides, which are the secondary ROS products of lipids oxidation, can predict cardiovascular events in patients with a history of cardiovascular diseases. Despite the clinical importance and the development of ROS detection assays, their application is limited in routine monitoring of oxidative stress as they require costly apparatus, experienced operators, and lack portability. Recent advances in biosensor technologies and the development of modern biosensors which exploit microfabrication technologies and optical, electrical or mechanical sensing technologies have the potential to deliver point-of-care diagnostics in resource poor settings. Among those digital biosensors utilizing electronic circuits are having a dramatic impact on healthcare due to their digital output and ease of data interpretation and distribution and have the potential to bring modern medicine in resource poor settings.
We have developed a digital polymer based sensor, termed ROC, which can detect circulating hydroperoxides in a POC manner. The ROC is composed of interdigitated microelectrodes (IDME) coated with a thin layer of a novel ROS responsive polymer. The presence of ROS in the sample leads to degradation of the polymer from the surface of the IDME, which generates a measurable electrical signal that correlates with the amount of ROS present. The ROC sensor was utilized to detect the amount of hydroperoxides, in the spiked blood sample. The results indicated an electrical response which linearly increased with the concentration of hydroperoxide. These results suggest that the ROC sensor can serve as an instrument-free and sensitive platform for ROS detection for routine clinical monitoring and in effort to prevent developing atherosclerosis.