A microfluidic based biosensor for rapid detection of Salmonella in food products

Abstract

An impedance based microfluidic biosensor for simultaneous and rapid detection of Salmonella serotypes B and D in ready-to-eat (RTE) Turkey matrix has been presented. Detection of Salmonella at a concentration as low as 300 cells/ml with a total detection time of 1 hour has been achieved. The sensor has two sensing regions, with each formed from one interdigitated electrode array (IDE array) consisting of 50 finger pairs. First, Salmonella antibody type B and D were prepared and delivered to the sensor to functionalize each sensing region without causing any cross contamination. Then the RTE Turkey samples spiked with Salmonella types B and D were introduced into the biosensor via the antigen inlet. The response signal resulted from the binding between Salmonella and its specific antibody demonstrated the sensor’s ability to detect a single type of pathogen, and multiple pathogens simultaneously. In addition, the biosensor’s selectivity was tested using non-specific binding of E . coli O157 and E . coli DH5 Alpha while the IDE array was coated with the Salmonella antibody. The results also showed the sensor is capable to differentiate low concentration of live Salmonella cells from high concentration of dead Salmonella cells, and high concentration of E . coli cells. A detailed study on antibody immobilization that includes antibody concentration, antibody coating time (0.5–3 hours) and use of cross-linker has been performed. The study showed that Salmonella antibody to Salmonella antigen is not a factor of antibody concentration after electrodes were saturated with antibody, while the optimal coating time was found to be 1.5 hours, and the use of cross-linker has improved the signal response by 45–60%.

A computational simulation platform for designing real-time monitoring systems with application to COVID-19

“…1 demonstrates the numerical domain and boundaries. Since variation of velocity in the span wise direction of this channel is negligible (due to negligible side wall effects on sensor surface), 2D simulation is valid for this case ( Liu et al, 2019 ).…”

“…Another common numerical study reported for this application is based on using an analytical velocity profile (assuming fully developed Poiseuille flow) in the convective-diffusive transport equation instead of using the converged velocity from Navier-stokes equations. Gelarkin finite-element method ( Selmi et al, 2017 ) and COMSOL commercial code ( Hu et al, 2007 ; Liu et al, 2019 ), (including FEMLAB, MATLAB subsidiary of COMSOL) are in this category, in which it has been reported that numerical results has more than 2 orders of magnitude difference with the experimental data ( Squires et al, 2008 ).…”

Biosensors for rapid detection of Salmonella in food: A review

“…Nowadays, much effort has been focused on novel sample pretreatment methods that are potential to be integrated into biosensors, including IMS (Du et al., 2018), microfluidic separation (He et al., 2013; Liu et al., 2019; Srbova et al., 2018), electrophoresis (Nguyen, Nguyen, Bui, & Seo, 2019; Zhang, Luo, et al., 2018), acoustophoresis (Ngamsom, Lopez‐Martinez, et al., 2016), magnetophoresis (Ngamsom, Esfahani, et al., 2016), and magnetic ionic liquid‐based extraction (Hice, Clark, Anderson, & Brehm‐Stecher, 2019). Among them, IMS has been regarded as one of the most useful tools for selective capture, separation, and concentration of Salmonella prior to detection.…”

Electrochemical and optical detection and machine learning applied to images of genosensors for diagnosis of prostate cancer with the biomarker PCA3

“…Much has been done in all of these challenges, as can be easily confirmed in the recent literature for various types of biosensors (see e.g. some review papers) [ [1] , [2] , [3] , [4] , [5] ]. However, this considerable body of knowledge has not been transformed into products for various reasons, the most important of which is perhaps the high cost of device engineering to develop tests and certify them through government agencies.…”