rapid detection of listeria monocytogenes in milk by surface plasmon resonance using wheat germ agglutinin

The current study made an attempt to develop a novel surface plasmon resonance (spr) sensor using wheat germ agglutinin as a biomolecule for the rapid detection of listeria monocytogenes. a selective biomolecular interaction of wheat germ agglutinin (wga) lectin with surface carbohydrate components of l. monocytogenes was used as a biorecognition principle. from the previous studies based on agglutination and sugar inhibition principle, we have selected wga as a highly selective ligand for l. monocytogenes-wga biomolecular interaction study using a spr (biacore 3000) sensor. under optimized assay conditions, l. monocytogenes strains have generated maximum response of 479 ± 49 resonance unit (ru) at 7.4 log cfu/100 μl with a least cross-reactivity in presence of both g+ve and g−ve bacterial contaminants. the limit of detection of 3.25 log cfu/100 μl was obtained for the detection of l. monocytogenes by lectin immobilized wga cm5 chip surface using spr. further, the wga-immobilized chip was evaluated with milk samples enriched in listeria selective enrichment medium and the response (ru) was again found to be significant up to 3.0 log cfu/100 μl.