The broad field of personalized medicine has been becoming more and more important in recent years, but as it is still in its infancy many challenges are to be mastered. One goal of personalized medicine is to determine the exact amount needed of a drug, which varies amongst individuals because metabolism of drugs happens at a different pace in each individual due to different amounts of enzymes present in our liver. For this application a microfluidic measurement chamber was developed that enables a continuous fluid flow as well as the integration of electrodes for electrochemical detection of the concentration of a substrate in a sample fluid. The design of the biosensor was evolved allowing a maximum amount of the sample fluid to get in direct contact with the enzymes immobilized on the working electrode while also respecting the constraints of additive manufacturing techniques at the same time. The electrodes are inkjet-printed using silver ink for the reference electrode whereas graphene ink is used for the working- and counter electrodes. The fluid flow through the measurement chamber was simulated and characterization of the electrodes is being done.