The need for the development of diagnostic tools, which allow for rapid and reliable analyses, is still of great importance. Recently, more and more attention has been paid to diagnostic systems, which can be used for point-of-care testing (POCT) for biomarkers and pathogens, assuring uncomplicated operations and rapid results. This presentation will cover several topics that must be considered upon designing and fabricating such devices, starting from the selection of biosensing elements and detection pathways, novel materials, and technologies, as well as appropriate analytical signal generation, data processing, miniaturization, and automatization of individual analytical steps up to cost-effectiveness. In the framework of this presentation, the electrochemical POCT system developed in our laboratory will also be presented. This system consists of: (i) disposable diagnostic cartridges containing a network of microchannels, bioreactor, specially designed carbon-based electrodes, and other elements (fabricated using a foil-to-foil technique), (ii) microelectronic reader, which can be used by doctors, nurses and paramedics under non-laboratory conditions, and (iii) a measurement data management system with accompanying infrastructure. This universal device can be applied for the determination/detection of bacterial, viral, and fungal antigens, as well as cardiovascular and hormonal biomarkers (in blood, urine, and nasal swabs and other biological samples). The applicability of the developed POCT system for the determination of certain biomarkers (e.g., C-reactive protein) will be demonstrated and evaluated.