This presentation will discuss customized manufacturing of Printed Circuit Board (PCB) using 3D printing technology (3D-PCB) for the module system of portable sensing applications. 3D printing technologies with various conductive materials will be presented and summarized along with development of printed sensors and their system applications. An optimized Directly Ink Writing technique is adapted in a novel 3D-PCB fabrication platform using silver nanoparticle based ink. An electro-chemical circuit called potentiostat, as an example, is designed and optimized from an open source circuit. Using the same 3D printing platform, a reliable lactate sensor with 3-electrodes is printed on the flexible substrate. By combination of 3D printed sensor and 3D-PCB, the 3D printed sensor system demonstrates the electrochemical test including cyclic voltammetry (CV) and amperometry. It is demonstrated that 3D-PCB technology can significantly accelerate the large-area fabrication process of conventional electronics, and merge its capability into electro-chemical applications.