In the present work, two biosensor models intended for determination of microbial cells have been developed. One of them uses an approach related to recognition of specific peculiarities of target cells' metabolism and is able to detect 10⁶ cells/sample. At the same time, it ensures the recognition of the detected microorganism only in the case of pure culture or qualitation of target on the background of microflora with the known metabolic pattern. Another model is based on the immunoassay technique and can be used for detection of target microorganism with the lower limit of detection of 10² cells/sample. The models' operation conditions have been optimized and preliminary conclusion concerning their application has been drawn.