Electrochemical Detection Method Using Serotonin Oxidation inside a Single Human Platelet

Abstract

An early diagnosis of platelet-related diseases is important for maintaining a healthy human life for blood clotting disorders caused by internal and/or external stimuli. Various technologies based on physics and chemistry have been developed for the detection of platelets. These methods are mainly set up in clinical laboratory and hospitals, cannot be portable, and require both complex pretreatment procedure and expensive detectors for platelet detection. Platelets are one of the human blood compositions and an important role in blood coagulation. Therefore, it is necessary to develop a method that can be adopted as a medical device capable of diagnosis in everyday life. We proposed an electrochemical collision method for direct detection of serotonin in a single platelet from human blood. This method is based on collisions of platelets with an ultramicroelectrode (UME) and observed the oxidation signal of serotonin without any modification of electrode through single-entity electrochemistry (SEE). When a platelet collides with the UME, secreted serotonin from the platelet gets oxidized at the electrode surface generating anodic currents. In our methods, the current for effective detection of platelets is very sensitive because there is no redox species. Studies on biomolecule detection through SEE can be useful for measuring the number of blood cells in our blood. Observing changes in the current that occur when platelets selectively collide with the UME, is medically useful information obtained cheaply and easily. The SEE method applied to blood analysis will be a new way to overcome the limitations of the existing sampling process, analysis time and environment. It is also expected to contribute to the development of high-performance sensors based on point-of-care-testing (POCT) devices capable of on-site and real-time diagnosis.