Figure 2.
TSP-based DNA electrochemical sensor. a) The presence of target DNA is transduced to electrochemical signals by the specific binding of an avidin-HRP (horseradish peroxidase) conjugate to the biotin label of the reporter probe and the resultant catalyzed electro-reduction of hydrogen peroxide in the presence of an electroactive cosubstrate, TMB, which offers high enzyme-based signal amplification. b) Amperometric measurements in the presence of target DNA at 1 pM, 10 pM, 100 pM, 1 nM, and 5 nM with the sandwich mode. c) Comparison of TSP and ssDNA probe-based sensor performance with or without MCH passivation (with 1 nM target DNA).