Electropolymerized eugenol: Evaluation as a protective film for oxygen sensing
by Paul, D. W.; Prajapati, I.; Reed, M. L.
Low oxygen levels in the brain are directly associated with stroke, and monitoring oxygen is essential to investigations of mechanisms in the brain that alter oxygen uptake. Most of the electrochemical detection schemes have focused on detecting neurotransmitters, nitric oxide, 5-HT, and dopamine, while excluding interferants, notably ascorbic acid. Despite the importance of oxygen in brain neurophysiology, very few reports for in vivo brain oxygen sensors have appeared recently in the literature. Amperometric detection using a membrane covered electrode is the basis of the Clark electrode and remains a popular method for measuring dissolved oxygen. Here we report on the performance of electropolymerized eugenol (PE) as a protective electrode film for oxygen sensing in vitro. Unlike dip-coatings that can only be evaluated after casting, it was discovered that the performance of the PE film can be anticipated from the current response seen in the electropolymerization step. PE proved to be a protective coating for a gold electrode; sensing oxygen in the presence of bovine serum albumin, which typically fouls uncoated electrodes. PE was also found to be impermeable to ascorbic acid. This is the first report where PE films have been used to develop a solid state electrode to sense oxygen in vitro.