Purpose: Biosensors act as analytical devices employing a biological material or biomimic as a recognition molecules integrated within a physicochemical transducer or transducing microsystems. This technique is rapid, economic, effective, and suitable for in situ analysis. This work was undertaken to develop low-cost, disposable sensors.
Methods: Agents or bacterial toxins or fragment from microbial infection 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, by binding analyte on the reactive surface, using biosensors with the specific reaction to specific antibodies.
Due to the selectivity of graphite-based amperometric detectors for significant substrates, it was the choice for the development of these 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/ml in a water solution of bacteria detected. The assays were specific and showed signal in the presence of all microorganisms tested, such as Escherichia coli O157:H7, Salmonella Typhimurium, Salmonella Enteritidis, and Listeria monocytogenes.
Significance: The advantages of the sensors that we developed are that they are: rapid, reliable, specific, and cost effective. Additionally, there is no need for trained workers and the equipment cost is minimal. Biosensors are an alternative to classical analytical methods. They are biochemical analytical methods with the advantages of being easy to handle, portable, quick, and the user does not require special skills.