Homogeneous Entropy Catalytic-Driven DNA Hydrogel as Strong Signal Blocker for Highly Sensitive Electrochemical Detection of Platelet-Derived Growth Factor.

In this work, an elegantly designed electrochemical biosensor was constructed for platelet-derived growth factor (PDGF) detection based on homogeneous entropy catalytic-induced DNA hydrogel as a strong signal blocker to significantly inhibit the electrochemical signal of g-CN@Au@Fc-NH nanomaterials as signal tag. First, the good film-forming nanomaterials of g-CN@Au@Fc-NH, containing large numbers of Fc-NH with low resistance and high electric conductivity, were directly immobilized on an electrode surface to provide a strong original electrochemical signal, then the DNA hydrogel blocker formed by target-induced homogeneous entropy catalytic amplification was captured onto the modified electrode surface for significantly reducing the electrochemical signal, in which both the efficient conversion of the single protein to large numbers of DNA strands and the amplification of cycling products could doubly improve the detection sensitivity. As a result, the detection limit could reach 3.5 fM at the range of 0.01 pM to 10 nM. The present strategy by integration of a strong signal blocker to sharply reduce the electrochemical signal of signal tag initiates a new thought to realize the highly sensitive detection of biomarkers and possesses potential applications in clinical diagnosis, sensing, and other related subjects.