Purpose: This technique is rapid, economic, effective, and suitable for in situ analysis. Biosensors act as analytical devices employing a biological material or biomimic, as a recognition molecules integrated within a physicochemical transducer or transducing microsystems.
Methods: Agents or bacterial toxins or fragments from microbial infections that can assure the presence of specific pathogenic bacteria were evaluated: Escherichia coli O157:H7, Salmonella Typhimurium, Salmonella Enteritidis, and Listeria monocytogenes. The analysis was performed in real time using biosensors with the specific reaction to specific antibodies, which bind analyte on the reactive surface. The selectivity of graphite-based, amperometric detectors for significant substrates was selected for the development of low-cost disposable sensors.
Results: We have developed a microbial based biosensor to determine the presence of specific pathogenic bacteria. This immunosensor was able to detect 80-100 cfu specified bacteria/ml in a water solution. The assays were specific and produced a signal in the presence of all microorganisms tested, such as Escherichia coli O157:H7, Salmonella Typhimurium, Salmonella Enteritidis, and Listeria monocytogenes.
Significance: We have the advantages of the use of sensors, which are rapid, reliable, specific, and cost effective and which do not require trained workers and use of minimaml equipment. Biosensors provide biochemical, analytical, alternatives to classical methods, with advantages like easy handling, portable, quick, and user-friendly.