This work received support from FICYT IE09-106 and IDEPA IDE/2012/000452. NC and IM belong to HIPSITEC SA and were taking part in this study in the following activities: NC in the conceptualization, investigation (construction of some of the plasmids for expression of the magic bullet biosensor proteins in S.albus), methodology (designing in part of the analyzer device for optical excitation and signal detection of the bound proteins to bacteria), supervision (of the engineering part of the project) and funding acquisition (proposals coordination and submission). IM in the methodology (tests with the device for checking signal detection parameters) and software (for controlling the LED-PMT-INTERFACE parts). We thank financial support from FICYT (Fundacion para el Fomento en Asturias de la Investigacion Cientifica Aplicada y la Tecnologia) and IDEPA (Instituto de Desarrollo Economico del Principado de Asturias) through the Projects IE09-106 and IDE2012/000452 to HIPSITEC SA. We also thank Servicios Cientifico-Tecnicos from the University of Oviedo for technical support in protein purification.