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Real-time pathogen determination by optical biosensing based on graphene oxide
Mariana D. Avila Huerta * , Edwin J. Ortiz-Riaño, Diana L. Mancera-Zapata, Eden Morales-Narváez
1  Centro de Investigaciones en Óptica, A. C

10.3390/IECB2020-07016 (registering DOI)

Pathogenic bacterial contamination in food is a public health concern. It represents a health and safety consumer risk that could cause several diseases and even death. Currently, the food industry uses culture-based assays to determine the presence of pathogens as a gold standard method. Although this method is highly accurate, it is often time-consuming and expensive.[1,2] In this regard, the development of biosensing platforms results as an alternative for the reduction of time and cost of pathogenic bacteria detection in food.[2] In this work, we report the development of a single-step bacterial detection platform based on graphene oxide. Non-radiative energy transfer between graphene oxide coated microplates (GOMs) and photoluminescence bioprobes (PLBs) is presented in absence of the target analyte, but in presence of analyte, PLBs exhibit strong photoluminescence due to the distance between GOMs and PLBs. These PLBs are a quantum dot- antibody complex, thereby resulting as a biorecognition and interrogation element. Escherichia coli was used as model analyte. In optimal conditions, the bacterial detection platform reached a limit of detection around 2 CFU mL-1 in 30 minutes, enabling a fast and sensitive alternative for bacterial detection. The biosensing platform was also used to test food industry samples achieving a qualitative response, that allows determining the presence of E. coli during the first 45 minutes of the assay. This biosensing strategy potentially offers a low-cost and quick option for the food industry to assure the quality of the product and consumer safety.[3]


[1] M. Majdinasab, A. Hayat, J. L. Marty, TrAC Trends Anal. Chem. 2018, 107, 60.

[2] Y. Wang, T. V. Duncan, Food Biotechnol. • Plant Biotechnol. 2017, 44, 74.

[3] M. D. Avila-Huerta, E. J. Ortiz-Riaño, D. L. Mancera-Zapata, E. Morales-Narváez, Anal. Chem. 2020, DOI 10.1021/acs.analchem.0c02200.

Keywords: one-step biosensing, fluorescence, pathogen detection, food analysis, 2D materials.
Comments on this paper
Maria Pesavento
Very interesting. Could you explain me how is the "selectivity" assured? What is the structure of the probe?
Mariana Avila Huerta
Thank you for your question, we tested the selectivity by analyzing a mix of a high concentration of the interference bacteria and a low concentration of target analyte. Then we analyzed a mix of a high concentration of the interference bacteria and a high concentration of target analyte. You could review it in Figure 3 of the paper, there is shown that the selectivity is effective in this system, and there is no crossreactivity. On the other hand, although the number of the real sample was relatively small, the platform exhibit 100% sensitivity and 100% specificity.
Mariana Avila Huerta
The probe is a complex of a quantum dot and antibodies. The quantum dots are coated with streptavidin (10 molecules) and the antibodies are biotinylated (around 8 molecules per antibody). Due to the affinity between the streptavidin and biotin is easy to make bonds during the conjugation.