Application Note #160
Detection of Salmonella is based on antibody (HRP-Ab2) binding on bacteria and bio-catalyzed precipitation by horseradish peroxidase. Binding of several HRP-Ab2 on one bacteria cause exponential amplification of the signal.
Contamination of food by pathogenic bacteria is a serious threat to human health and thus biosensors for fast and accurate food quality control are extensively studied.
Multi-Parametric Surface Plasmon Resonance (MP-SPR) based biosensor was developed to detect Salmonella Typhimurium in dairy products. Direct label-free detection of bacteria by using a capture antibody was further improved utilizing bio-catalyzed precipitation. For control samples the limit of detection (LOD) was 102 CFU/mL and for real samples (powdered milk) LOD was 103 CFU/mL, demonstrating a high sensitivity of the biosensor.