Integrated electrochemical sensors in which plasma-treated poly(lactic acid) (PLA) single material acts as both selective coating layer and electrochemical transductor (electrode) are prepared. Thus, three-dimensional-printed PLA specimens are transformed into electroresponsive material by applying a low-pressure gas plasma treatment with three different gases: N2, O2, and air (79% N2¿+¿21% O2). Although all treated samples are able to electrochemically detect dopamine, the one derived from the treatment of low-pressure O2 plasma exhibits the best performance as a sensor. Finally, cell adhesion assays demonstrate that the cell viability is higher for plasma-treated PLA modified than for pristine PLA, making the former a promising, versatile, and powerful electroresponsive platform for diverse applications in biomedicine.