Electrochemical approach in studying the inhibition of acetylcholinesterase by arsenate(III): analytical characterisation and application for arsenic determination

The inhibition action of arsenate(III) on the activity of the enzyme acetylcholinesterase immobilised on the surface of a graphite electrode is investigated, using an electrochemical approach. It is demonstrated that the value of the registered amperometric signal depends on the AsO3−3 concentration. Parameters useful for the quantitative arsenate(III) determination (dynamic range, detection limit, sensitivity) are evaluated. pH dependencies and kinetic phenomena are discussed. A distinction between As(III) and As(V) species is made. The method is applied for estimating the arsenic contents in industrial waters after Cu2+ and Fe3+ elimination in the form of hydroxides.