Detección electroquímica de Escherichia coli O157:H7 en agua utilizando biosensores peptídicos modificados

Abstract

The contamination generated by the presence of microorganisms such as Escherichia coli O157:H7 represents an environmental and social problem, due to the serious diseases presented by this pathogen. The timely detection of this microorganism presents some disadvantages with respect to traditional techniques, therefore, it is necessary to develop new technologies for the detection of this microorganism in water with shorter detection times, therefore, in this work it is presented an alternative for the detection of Escherichia coli O157:H7 through the use of electrochemical biosensors based on PEPTIR peptides. The determination of the analytical characteristics of the peptide-based electrochemical biosensor PEPTIR was carried out by immobilizing PEPTIR 1 and PEPETIR 2 at different concentrations of 5, 10, 50 and 100 nM, seeking to guarantee the immobilization and detection of Escherichia coli O157: H7. For this, the analytical characteristics of the electrochemical biosensors were evaluated using electrochemical techniques such as cyclic voltammetry (CV), square wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS), thus evaluating the effect of the modifications made on the working electrode. of the electrochemical biosensor. Obtaining as a result the optimal concentrations of PEPTIR 1.0 and PEPTIR 2.0, improving the detection limits and quantification limit at different concentrations of microorganism 10, 20, 50, 100, 300 CFU/mL. On the other hand, the selectivity of the peptide-based biosensor for PEPTIR 1.0 and PEPTIR 2.0 against Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus was evaluated, resulting in a high selectivity with respect to other microorganisms.