A novel label-free and signal-on electrochemical aptasensor based on the autonomous assembly of hemin/G-quadruplex and direct electron transfer of hemin

摘要: Abstract In this study, we developed a signal-on and label-free aptasensor based on the direct electron transfer of hemin signal amplification by target-catalyzed hairpin assembly followed hybridization chain reaction (HCR). Upon addition target protein, it facilitates opening structure A1 thus accelerates between A2; protein was displaced from with A2 through process similar to DNA branch migration. The released participates in next A1. Finally, each passes many cycles, confining numerous close gold electrode. Subsequently, single-strand fragment electrode surface initiated HCR, resulting form double-strand concatemers surface. Consequently, stacked into G-quadruplex-forming region, hemin/G-quadruplex formed, generating an amplified electrochemical differential pulse voltammetry. our sensing approach, introduction HCR significantly enhanced sensor response. Moreover, approach is free any label conjugation step for simple has great potential development robust aptasensors.