Abstract
| - The on-line coupling of a label-free optical biosensor to aHPLC system is described by combining the separationpower of HPLC with the specificity of the biosensorsystem. A highly cross-reactive antibody against thepesticide isoproturon was used as model for affinityproteins. The binding strength of the antibody to theutilized pesticides was characterized with the biosensor,first. In the on-line coupling setup, the eluate of the HPLCwas mixed continuously with the antibodies. The presenceof antigens was detected by a reduction of the antibodybinding to the transducer. This reduced binding wasquantified by a differentiation of the sensor signal byapplying a Savitzky−Golay algorithm. Limits of detectionwere found to be in the femtomole range without preconcentration, which is comparable to a study using fluorescence-based biochemical detection.
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