Conductometric Immunosensor for Escherichia coli O157:H7 Detection Based on Polyaniline/Zinc Oxide (PANI/ZnO) Nanocomposite

Sawsan Mutlaq; Borhan Albiss; Anas A Al-Nabulsi; Ziad W Jaradat; Amin N Olaimat; Mohammad S Khalifeh; Tareq Osaili; Mutamed M Ayyash; Richard A Holley

doi:10.3390/polym13193288

Conductometric Immunosensor for Escherichia coli O157:H7 Detection Based on Polyaniline/Zinc Oxide (PANI/ZnO) Nanocomposite

Polymers (Basel). 2021 Sep 26;13(19):3288. doi: 10.3390/polym13193288.

Authors

Sawsan Mutlaq¹, Borhan Albiss², Anas A Al-Nabulsi¹, Ziad W Jaradat³, Amin N Olaimat⁴, Mohammad S Khalifeh⁵, Tareq Osaili^{1

6}, Mutamed M Ayyash⁷, Richard A Holley⁸

Affiliations

¹ Department of Nutrition and Food Technology, Jordan University of Science and Technology, P.O. Box 3030, Irbid 22110, Jordan.
² Nanomaterials Laboratory, Department of Applied Physics, Jordan University of Science and Technology, P.O. Box 3030, Irbid 22110, Jordan.
³ Department of Biotechnology and Genetic Engineering, Jordan University of Science and Technology, P.O. Box 3030, Irbid 22110, Jordan.
⁴ Department of Clinical Nutrition and Dietetics, Faculty of Applied Medical Sciences, The Hashemite University, P.O. Box 330127, Zarqa 13133, Jordan.
⁵ Department of Basic Medical Veterinary Sciences, Jordan University of Science and Technology, P.O. Box 3030, Irbid 22110, Jordan.
⁶ Department of Clinical Nutrition and Dietetics, College of Health Sciences, University of Sharjah, Sharjah P.O. Box 27272, United Arab Emirates.
⁷ Department of Food Science, College of Agriculture and Veterinary Medicine, United Arab Emirates University (UAEU), Al Ain P.O. Box 15551, United Arab Emirates.
⁸ Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.

Abstract

A conductometric immunosensor was developed for the detection of one of the most common foodborne pathogens, Escherichia coli O157:H7 (E. coli O157:H7), by conductometric sensing. The sensor was built based on a polyaniline/zinc oxide (PANI/ZnO) nanocomposite film spin-coated on a gold electrode. Then, it was modified with a monoclonal anti-E. coli O157:H7 antibody as a biorecognition element. The fabricated nanostructured sensor was able to quantify the pathogens under optimal detection conditions, within 30 min, and showed a good detection range from 10¹ to 10⁴ CFU/mL for E. coli O157:H7 and a minimum detection limit of 4.8 CFU/mL in 0.1% peptone water. The sensor efficiency for detecting bacteria in food matrices was tested in ultra-heat-treated (UHT) skim milk. E. coli O157:H7 was detected at concentrations of 10¹ to 10⁴ CFU/mL with a minimum detection limit of 13.9 CFU/mL. The novel sensor was simple, fast, highly sensitive with excellent specificity, and it had the potential for rapid sample processing. Moreover, this unique technique for bacterial detection could be applicable for food safety and quality control in the food sector as it offers highly reliable results and is able to quantify the target bacterium.

Keywords: E. coli O157:H7; antibody; immunosensor; polyaniline; zinc oxide nanoparticles.