Enzyme-assisted isothermal amplification of nucleic acids on the electrode surface

The detection of genetic material (DNA or RNA) is becoming increasingly important not only in the clinical practice but also in food quality control or environmental analysis. Since the amount of the specific nucleic acid sequences targeted is often very low, nucleic acid tests usually involve an amplification step, which makes many copies of the target. Although the polymerase chain reaction (PCR) is the gold standard, nature provides amplification systems that proceed at a constant temperature and are easier to adapt to electrochemical platforms for point-of-need applications. In this short review, we chronicle the evolution of enzyme-assisted isothermal nucleic acid amplification strategies, specifically helicase-dependent amplification (HDA), loop-mediated isothermal amplification (LAMP), and recombinase polymerase amplification (RPA), directly coupled to conductive platforms to facilitate the electrochemical transduction, describing the current state of the art, and identifying some of the challenges to bring these new platforms to the real practice as point-of-need tests.