Cyclodextrins-based enantioselective, potentiometric membrane electrodes for l-vesamicol assay in serum samples

Abstract

Four enantioselective, potentiometric membrane electrodes based on cyclodextrins (α-, β-, γ- and 2-hydroxy-3-trimethylammoniopropyl-β-cyclodextrin (as chlorine salt) (β-derivative-cyclodextrins)) have been constructed for the analysis of l-vesamicol. The linear concentration ranges for the proposed EPMEs based on cyclodextrins were from 10 −9 to 10 −7 mol l −1 for those electrodes based on α-, β- and β-derivative-cyclodextrins with detection limits of 5.7 × 10 −10, 2.42 × 10 −10 and 4.77 × 10 −10 mol l −1, respectively, while γ-cyclodextrin-based electrode is characterized by linear concentration range 10 −5 to 10 −2 mol l −1 with detection limit of 7.86 × 10 −6 mol l −1. The electrodes displayed near-Nernstian slopes of 52–59 mV per decade of l-vesamicol concentration. The electrodes were used for the direct assay of l-vesamicol in serum samples and proved to be reliable, reproducible and stable. The surface of the electrodes can be simply renewed by polishing on alumina paper to obtain a fresh surface ready for use in a new test.