Electrochemical screening of biological membrane active compounds

Interactions of biomembrane-active compounds with phospholipid monolayers on microfabricated Pt/Hg electrodes in an on-line high throughput flow system are demonstrated by recording capacitance current peak changes in rapid cyclic voltammograms (RCV). Detection limits of the compounds' effects on the layer have been estimated from the data. Compounds studied include steroids, polycyclic aromatic hydrocarbons, tricyclic antidepressants, tricyclic phenothiazines pyridinium compounds, spiperone and spiperone analogues and a range of serotonin and dopamine receptor ligands. The results show that the extent and type of interaction depends on the: - (a) presence and number of aromatic rings and substituents, (b) presence and composition of side chains and, (c) molecular shape. Interaction is only indirectly related to compound hydrophobicity. For a selection of tricyclic antidepressants and tricyclic phenothiazines the detection limit in water is related to their therapeutic normal threshold. The sensing assay has been tested in the presence of humic acid as a potential interferent and in a tap water matrix. It was subsequently tested in a natural water matrix. The system can be applied to the screening of putative hazardous substances allowing for early detection thereof in the water supply. The measurements are made in real time which means that potentially toxic compounds are detected rapidly in <10 minutes per assay. This technology will contribute greatly to environment safety and health.