Paper-Based Electrodes Conjugated with Tungsten Disulfide Nanostructure and Aptamer for Impedimetric Detection of Listeria monocytogenes.

Annu Mishra,Manika Khanuja,Roberto Pilloton,Swati Jain,Souradeep Roy,Jagriti Narang,Ashish Mathur

doi:10.3390/bios12020088

Abstract

In this study, we report on a novel aptasensor based on an electrochemical paper-based analytical device (ePAD) that employs a tungsten disulfide (WS2)/aptamer hybrid for the detection of Listeria monocytogenes. Listeria is a well-known causative pathogen for foodborne diseases. The proposed aptasensor signifies many lucrative features which include simple, cost-effective, reliable, and disposable. Furthermore, the use of an aptamer added more advantageous features in the biosensor. The morphological, optical, elemental composition, and phase properties of the synthesized tungsten disulfide (WS2) nanostructures were characterized by field-emission scanning electron microscopy (FESEM), RAMAN spectroscopy, photoluminescence (PL), and X-ray diffraction (XRD), while electrochemical impedance spectroscopy was performed to corroborate the immobilization of aptamer and to assess the L. monocytogenes sensing performance. The limit of detection (LoD) and limit of quantification (LoQ) of the aptasensor was found to be 10 and 4.5 CFU/mL, respectively, within a linear range of 101–108 CFU/mL. The proposed sensor was found to be selective solely towards Listeria monocytogenes in the presence of various bacterial species such as Escherichia coli and Bacillus subtilis. Validation of the aptasensor operation was also evaluated in real samples by spiking them with fixed concentrations (101, 103, and 105) of Listeria monocytogenes, thereby, paving the way for its potential in a point-of-care scenario.

Highlights

Introduction iationsFoodborne pathogens have proven to be a severe threat to the food industries that deal with important public health crises across the world [1]
We report on the analytical performance of a WS2 /aptamer hybridbased aptasensor towards the selective detection of Listeria monocytogenes in an experimentally synthesized electrolyte as well as spiked dairy products, thereby, validating the developed sensor as a potential candidate for specific and sensitive bacterial detection
The morphological and structural properties of synthesized WS2 were performed by field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), RAMAN, and PL

Summary

Introduction

Foodborne pathogens have proven to be a severe threat to the food industries that deal with important public health crises across the world [1]. Organization (WHO), foodborne diseases affect approximately one-third of the population in developed countries annually, while this ratio is even higher in developing nations [2]. Bacteria such as Listeria monocytogenes, a harmful organism (e.g., human listeriosis), is a considerable concern for pregnant women, infants, and adults who are suffering from a weak immune system [3]. The consequences associated with this bacterium are the foremost concern in food industry treatments

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Conclusion