Capture agents for a quartz crystal microbalance-continuous flow biosensor: functionalized self-assembled monolayers on gold

摘要: Abstract For a model system, we used gangliosides as capture agents on the gold electrode surface of quartz crystal microbalance (QCM) to detect cholera toxin (CT) and closely-related Escherichia coli heat-labile enterotoxin (LT) in continuous-flow cell. Positive signals were verified by introduction anti-CT anti-LT antibodies. Antibody binding captured analyte was corroborated positive from appropriate anti-immunoglobulin antibody manner analogous solid-phase enzyme-linked immunoassay (ELISA). While ganglioside receptor analogs are stable, easy apply have high affinity for particular bacterial toxins, they disadvantage endogenous materials likely be found biological sample. To avoid this problem, devised self-assembled monolayer (SAM) that can modified with functional group able covalently bind orient immunoglobulins without loss activity. We present preliminary results demonstrating formation SAM linker terminating hydrazide functionality. The link active against E. O157:H7 monolayer. antibody-derivatized QCM detected at concentrations 107 104 cells per ml through flow-cell. provide exquisite specificity, sensitivity an essentially unlimited range coupled analytical purposes.