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United States Department of Agriculture

Agricultural Research Service

Research Project: Conversion of Polysaccharides and Other Bio-based Materials to High-Value, Commercial Products

Location: Plant Polymer Research

Title: Electrochemical characterization of an immunosensor for Salmonella spp. detection

Author
item Araujo Melo, Airis
item Alexandre, Dalila
item Furtado, Roselayne
item De Fatima Borges, Maria
item Alves, Carlucio
item Vasconcelos Ribeiro, Paulo
item Biswas, Atanu
item Cheng, Huai
item De Figueiredo, Evania

Submitted to: New Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/5/2017
Publication Date: N/A
Citation: N/A

Interpretive Summary: Salmonella is a major foodborne pathogen in the world and can infect animals and humans alike. Analysis for Salmonella spp. in food is one of the mandatory procedures in order to guarantee food safety. However, conventional detection methods are laborious and time-consuming, sometimes requiring several days to confirm the results. In this work, an electrochemical immunosensor was developed and optimized such that Salmonella can be detected at a detection limit of 10 CFU mL-1. The detection time can be as low as 125 minutes for each test. This work is important because it can serve as a useful tool for food safety; for example, it can be used by government health officials and food suppliers worldwide to monitor food quality and ensure food safety.

Technical Abstract: Immunosensors represent a rapid alternative method for diagnosing Salmonella contamination. The objective of this study was to develop and evaluate the performance of an electrochemical immunosensor for the detection of Salmonella spp., the most common foodborne pathogen worldwide. In the immunosensor assembly, a gold surface was modified by the self-assembled monolayer technique (SAM) using cysteamine and protein A for immobilization of polyclonal antibody to Salmonella spp. Optimization studies were carried out in order to determine the ideal concentrations of biomolecules and reagents for immunosensor development. The chronoamperometry technique, using a sandwich assay with horseradish peroxidase (HRP)-labeled antibody, was used as the analytical response. The immunosensor was characterized by ATR-FTIR, scanning electron microscopy, and electrochemical measurements. The optimization studies for protein A and primary antibody concentrations resulted in a higher analytical signal at 7.5 and 75.0 mg mL-1, respectively. The hydroquinone and H2O2 concentrations selected were 3 mM and 300 mM, respectively. The immunosensor appears to be a viable method for Salmonella detection with a detection limit of 10 CFU mL-1 and detection time of 125 minutes for the final response. It is also a very promising tool for food safety.

Last Modified: 09/24/2017
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