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ARS Home » Northeast Area » Wyndmoor, Pennsylvania » Eastern Regional Research Center » Characterization and Interventions for Foodborne Pathogens » Research » Publications at this Location » Publication #376323
Research Project: Advanced Development of Innovative Technologies and Systematic Approaches to Foodborne Hazard Detection and Characterization for Improving Food Safety

Location: Characterization and Interventions for Foodborne Pathogens

Title: Aptamer-based SERS biosensor for whole cell analytical detection of E. coli O157:H7

Author
item DIAZ-AMAYA, S - Purdue University
item LIN, L - Purdue University
item STANCIU, L - Purdue University

Submitted to: Analytica Chimica Acta
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/22/2019
Publication Date: 6/23/2019
Citation: Diaz-Amaya, S., Lin, L.K., Stanciu, L.A. 2019. Aptamer-based SERS biosensor for whole cell analytical detection of E. coli O157:H7. Analytica Chimica Acta. 1080:131-137. https://doi.org/10.1016/j.aca.2019.06.046.
DOI: https://doi.org/10.1016/j.aca.2019.06.046

Interpretive Summary: Infectious diseases induced by foodborne pathogens such as E. coli O157:H7 still have a high negative impact on human health. This work evaluates the incorporation of aptameric DNA sequences as detection reagents. DNA-based aptamer probes were used to detect low concentrations of E. coli O157:H7 within 20'minutes in both pure culture and ground beef samples. The probes were shown to be able to detect pathogens with high specificity and sensitivity and could form the basis for the production of inexpensive test strips that could be deployed in production facilities, food safety testing labs, or for use in further research.

Technical Abstract: Infectious outbreaks caused by foodborne pathogens such as E. coli O157:H7 are still imposing a heavy burden for global food safety, causing acute illnesses and significant industrial impact worldwide. Despite the growth of biosensors as a research field, continuous innovation on detection strategies, novel materials and enhanced limits of detection, most of the platforms developed at the laboratory scale never will get to meet the market. The use of aptamers as capture biomolecules has been proposed as a promising alternative to overcome the harsh environmental conditions of industrial manufacturing processes, and to enhance the performance under real, complex, conditions. In this work, we present the feasibility of using aptameric DNA sequences, covalently conjugated to 4-aminothiophenol-gold nanoparticle complexes for the sensitive and highly specific detection of E. coli O157:H7 via surface enhanced Raman spectroscopy (SERS)analysis. Low concentrations of E. coli O157:H7 were detected and quantified within 20 min in both pure culture (~101 CFU mL1) and ground beef samples (~102 CFUmL1). The SERS intensity response showed a strong negative linear correlation (r2 ¼ 0.995) with increasing concentrations of E. coli O157:H7(ranging from 102 to 106 CFU mL1). High specificity was achieved at genus (L. monocytogenes, S. aureus S.typhimurium) species (E. coli B1201) and serotype (E. coli O55:H7) level, demonstrating with 95% of confidence that the interferent microorganisms tested generated a Raman signal response not significantly different from the background (p ¼ 0.786). This work evaluates the incorporation of aptameric DNA sequences as bio capture molecules exclusively. The successful performance presented using non-modified citrate reduced GNPs, is promising for potential low-cost, high-throughput applications. The findings might be applied simultaneously to the detection of a wide variety of foodborne pathogens in a multiplexed fashion employing unique Raman probes and strain-specific aptamer sequences.