The target DNA (in red color) hybridized with the capture DNA and opened their loop parts, enabling a primer with DNA–invertase conjugation to attach on the stem part, which initiated a polymerization which replaced the target with the aid of the DNA polymerase I.The released target then found another capture DNA to trigger another polymerization cycle, which was repeated for many rounds, resulting in the multiplication of the DNA–invertase conjugation on the surface of Streptavidin-MNBs.