Biosensor Arsen(III) Menggunakan Elektrode Pasta Karbon Termodifikasi Partikel Nanozeolit-Fe dan Pengaruh Keberadaan Timbal(II)

Abstract

Ion detection of arsenic(III) with biosensors using enzyme inhibition principle can be used as a method for detecting arsenic(III) ions in waters. Biosensor is made of carbon paste electrode as modified using zeolite-Fe nanoparticles and the enzyme pyruvate dehydrogenase (PDH) as an agent of biological activity identifier that will be inhibited by the presence of arsenic(III) ions. PDH was immobilized on the surface of the electrode. The optimum condition of enzyme activity was at 33 ᵒC , pH 7, and [PDH] 0.0141 U/mL. The activity of PDH was linear in the range of 0.6-20 ppb arsenic(III) ion concentracions with R2 = 0.9932. Detection limit and quantitation limit were 2.06 and 6.99 ppb, respectively. The electrode was relatively stable for 3 days, with good repeatability at %RSD of 1.98%. The existence Pb(II) ion did not interfere the performance of the ion electrode measurements of As-(III), as the value of Ki,j was <1.