Electrochemical Biosensor for Detection of Bioagents

Simple and rapid detection and identification of dangerous bioagents is important for preventing illness or even death of people due to infectious diseases and bioterrorist threats. Electrochemical detection has a large potential for development of portable instrumentation suitable for analysis in field and especially combination with specificity of immunoassays seems promising. Initially, the construction of the immunosensing layer was realised and the effect of Au nanoparticles on the response of peroxidase was studied. An amperometric immunosensor was developed using screen-printed transducer, it employed specific capture of microbes in the sensing area by formation of an immunocomplex and its subsequent labelling using the tracer - antibody conjugated to peroxidase. The obtained sandwich electrochemical immunoassay was applied for the model microbial cells of B. subtilis. The total time of analysis was 20 min and the detection of cells below 104 CFU/ml was feasible. The presence of microbial cells at the sensing surface was confirmed using atomic force microscopy. The results appear promising for combination of the immunosensor with a cyclone sampler and analysis of Bacillus-based bioaerosols in field trials.