Scheme 1. (A) Equivalent logic circuit of the 2-bit even pG and 3-bit even pC; the sad and smiling faces represent erroneous and normal outputs, respectively. (B) Schematic illustration of the operating principle of the electrochemical pG/pC system; the red basket indicates the thrombin aptamer that functions as a “nanoclaw”. The blue “√” and red “×” symbols represent favourable and blocked electron transfer, respectively.