Ultrasensitive electrochemical detection of microRNA based on an arched probe mediated isothermal exponential amplification.In this work, a simple and label-free electrochemical biosensor is developed for microRNA (miRNA) detection on the basis of an arched probe mediated isothermal exponential amplification reaction (EXPAR).  The other strand liberated into the solution triggers the EXPAR to recycle and regenerate targets. 
EXPAR
The strand fixed on the surface of the electrode self-assembles, in the presence of hemin, to G-quadruplex unit, yielding electrochemical signals. 
hemin