Optimization and application of a dithiobis-succinimidyl propionate-modified immunosensor platform to detect Listeria monocytogenes in chicken skin

This research aims to demonstrate the potential feasibility of a surface modified gold-coated immunosensor platform combined with light microscopic imaging system (LMIS) to detect Listeria monocytogenes in chicken. The reactivity of custom prepared antibodies (P-pAbs) was significantly higher than the reactivity of commercial antibodies and the P-pAbs were highly specific with L. monocytogenes strains. A gold-coated sensor platform modified with dithiobis-succinimidyl propionate (DSP) exhibited a 40% increase in binding efficiency, compared to the gold-coated sensor platform. The optimum concentration and incubation time for P-pAbs immobilization on DSP-modified sensor platform was determined as 100 μg/ml and 45 min, respectively. The optimum incubation time and pH range for binding between L. monocytogenes and P-pAbs were determined as 45 min and pH 5.5–9.5, respectively. The limit of detection of DSP-modified immunosensor platform to detect L. monocytogenes in chicken skin was determined as 103 CFU/25 g, exhibiting 66% positive rate. Observing the images from LMIS demonstrated that the DSP-modified immunosensor platform provided an easy differentiation between L. monocytogenes and attached food particles in chicken products.