A highly sensitive microfluidic biosensor for rapid and accurate detection of Salmonella in raw chicken products

Abstract

• The limit of detection is 1-2 cells/ml in chicken carcass wash spiked with Salmonella • The overall detection time is 40-50 min. • The addition of the focusing and trapping regions significantly enhanced the sensitivity • The device differentiated live from dead Salmonella cells. • The device demonstrated high specificity and selectivity. This paper presents an investigation of a fluidic-based impedance biosensor for rapid and accurate detection of Salmonella Typhimurium in raw chicken carcass rinsate. The biosensor is engineered with multiple distinct regions that concentrates Salmonella antigens to a detectable level, subsequently trapping the concentrated Salmonella samples on top of the detection interdigitated electrode array coated with a specific Salmonella antibody, maximizing the number of captured antigens. Detection is achieved through the antibody-antigen binding process, where binding events changes impedance values, providing a reliable method for identifying and quantifying Salmonella . The biosensor demonstrated a low limit of detection (LOD) of 1-2 cells/ml within 40-50 minutes. The findings demonstrated that the biosensor distinguishes low concentrations of live Salmonella cells, even in the presence of high concentrations of dead Salmonella cells, and non-specific binding pathogens viz., Listeria monocytogenes and E. coli O157:H7 .