AbstractThis paper reports the characteristics of folding‐based electrochemical DNA sensors fabricated on recessed nanodisk‐array electrodes (RNEs). The RNEs were based on gold substrates coated with polystyrene‐block‐poly(methylmethacrylate)‐derived thin films (30 nm thick) comprising vertically‐oriented cylindrical nanopores (14, 20 or 30 nm in diameter). RNE‐based sensors were fabricated by modifying the underlying gold surface with a stem‐loop DNA probe with a terminal methylene blue (MB) tag. The electrochemical responses of such RNE‐based sensors to complementary single‐stranded 17‐mer DNA were compared with those of film‐free counterparts using cyclic voltammetry. RNE‐based sensors exhibited signal suppression at a significantly lower target DNA concentration than film‐free sensors, possibly due to the manipulated dynamic properties of the MB tag as suggested by its apparent electron transfer rate constant and/or enhanced hybridization within the nanopores. These results indicate that RNEs provide unique platforms for developing folding‐based electrochemical sensors with improved sensitivity.