In order to improve the sensitive for DNA assay, target amplification is usually used, especially for enzyme-assisted am- plification. Among them, polymerase chain reaction (PCR) is the most widely used one, as its high sequence specificity and amplification yield. However, in the procedure of PCR, small contaminants can also be amplified, which leads to false-positives and the requirement for thermal cycling and experimental expertize in PCR technique have ultimately restricted its widespread application. Alternatively, a number of new methods of target amplification have been proposed