The aim of the study is to open a new scope for organic electrochemical transistors based on PEDOT:PSS, a material blend known for its stability and reliability. These devices can leverage molecular electrocatalysis by incorporating small amounts of nano-catalyst during the transistor manufacturing (spin coating). This methodology is very simple to implement using the know-how of nanochemistry and results in efficient enzymatic activity transduction, in this case utilizing choline oxidase and glutamate oxidase. ; Funding Agencies|EU [PIEF-GA-2011-301796]; Onnesjo foundation; Swedish Research Council [2002-4497]; Swedish Foundation for Strategic Research [IMF11-0052]; Knut and Alice Wallenberg Foundation [2012-0302]