A micro-immuno supported liquid membrane assay (μ-ISLMA)

A chemiluminescent (CL) based micro-immuno supported liquid membrane assay (μ-ISLMA) has been developed that enables clean up, enrichment and detection of simazine in a single miniaturised cartridge system. The μ-ISLM cartridge contains a supported liquid membrane (SLM) sandwiched between a donor and an acceptor plate (channel volumes 1.65 μL), the latter being covered by a thin layer of gold on to which anti-simazine antibodies were covalently immobilised via a self assembled monolayer (SAM) of either dithiobis(11-aminoundecane, hydrochloride) (DTAU) or β-mercaptoethylamine (β-MEA). The μ-ISLMA based on DTAU was characterised by both a high apparent extraction efficiency (Eapp = 136%) and high apparent enrichment factor (Eeapp = 544), which resulted in a very high sensitivity for simazine (LOD = 0.1 ng L−1). The paper discusses the influence of the different SAMs and three different anti-simazine-antibody preparations (polyclonal, affinity purified polyclonal and monoclonal) on the extraction parameters and assay sensitivity. The influence of the sample matrix (e.g. mineral water, orange juice and milk) on the simazine μ-ISLMA was also investigated.