Highly Sensitive Detection of miRNA-21 Based on Electrochemical Immunosensor

Inflammation is one of the main mechanisms of neurological damage after ischemia and hypoxia in brain tissue and plays an important role in the progression of ischemic stroke. Microglia, as intrinsic immune cells of the central nervous system, are involved in the pathophysiological process of cerebral ischemia by mediating inflammation. miRNA-21 may be involved in the pathophysiology of diseases such as ischemic stroke and atherosclerosis through the regulation of inflammatory processes. In this work, methylene blue-modified stem-loop structural probes were immobilized on the sensor surface. With the addition of miRNA-21, the signal of methylene blue is gradually diminished. Therefore, the quantitative detection of miRNA-21 can be achieved by the alteration of electrochemical signal.