Rapid Evaluation of Salmonella pullorum Contamination in Chicken Based on a Portable Amperometric Sensor

Guoyan Liu Chunyan Chai

doi:10.4172/2155-6210.1000137

Abstract

In this study, anti-Salmonella polyclonal antibodies immobilized on cellulose nitrate membrane were used to capture Salmonella pullorum (S. pullorum) in biological samples. The rapid evaluation of S. pullorum contamination was based on the analysis of the activities of catalase, a biomarker of this bacterium. After a screen printed electrode (SPE) modified with multi-wall carbon nanotubes (MWCN)-chitosan-peroxidase was connected to a portable selfmade amperometric sensor, the determination of S. pullorum contamination was carried out by adding the reaction product, which was obtained from the hydrogen peroxide dismutation catalyzed by the bacterial catalase, to the reacting area of the SPEs. A working potential of 0.55 V was applied in the sensing system and the current value displayed on the amperometric sensor was used as the detection signal. This method allowed the quantification of S. pullorum with the detection limit of 100cfu mL-1 in culture media and chicken samples. The stability, reproducibility and sensitivity of the modified SPE were also investigated. Moreover, successive analysis was conveniently accomplished by replacing the one-off SPE. This portable sensing system is a rapid, cost-effective and straightforward approach for screening S. pullorum contamination in food samples.

Highlights

Salmonella, one of the most frequently reported causes of food-borne illness in the world, is widely distributed in animals and environment [1,2,3]
We designed and fabricated a novel biosensor for fast detection of S. pullorum contamination in food samples by using multi-wall carbon nanotubes (MWCN)-chitosan-peroxidase modified screen printed electrode (SPE) and anti-Salmonella polyclonal antibodies immobilized on cellulose nitrate membrane
Horseradish peroxidase (HRP) (EC 1.11.1.7, type I, activity 148U mg-1 of solid), bovine serum albumin (BSA), N, N, N’, N’tetramethylbenzidine dihydrochloride (TMB) and ferrocene were purchased from Sigma

Summary

Introduction

Salmonella, one of the most frequently reported causes of food-borne illness in the world, is widely distributed in animals and environment [1,2,3]. Several rapid approaches and alternative methods have been developed for the detection of Salmonella, including polymerase chain reaction [20,21,22,23,24], immunoassay [25,26,27,28], bioluminescence [29,30] and impedimetry [31,32,33] The drawbacks of these applications are the complexity and limited applicability for on-site detection. We designed and fabricated a novel biosensor for fast detection of S. pullorum contamination in food samples by using MWCN-chitosan-peroxidase modified SPEs and anti-Salmonella polyclonal antibodies immobilized on cellulose nitrate membrane. We hypothesized that these techniques are very helpful to improve the sensitivity and selectivity of this sensing system. In practical on-site use, the determination of S. pullorum can be carried out after a modified SPE is connected to a portable self-made amperometric sensor and successive analysis can be conveniently accomplished by replacing the one-off SPE

Materials and Methods

Results and Discussion

Conclusion