engleski

Impedimetric Au-NTA sensor for lead determination

Recently, we have developed a chemically modified gold electrode by using nitrilotriacetic acid (NTA) functionalized thiol monolayers prepared by soaking a cysteamine attached gold electrode in an aqueous solution of NTA.Thiol monolayers prepared on gold electrode serve as the anchor layer to immobilize NTA molecules using EDC/NHS chemistry.Existence of each layer on the top of disc gold electrode was confirmed by cyclic voltammetry and electrochemical impedance spectroscopy(EIS) in acidic and basic solution using Fe(CN)63-/4- redox pair. The electrode prepared in this way was used for lead determination.The binding of Pb2+ onto the modified electrode was successfully performed in a wide range of tested concentrations and was confirmed by EIS. Electrode response (log Rct) was linerly proportional to log c (Pb) with squared correlation coefficient R2 = 0.9865 for measurements in acetic buffer pH = 4.6 and R2 = 0.9931 for measurements in boric buffer pH =7.0 at micromolar concentration level.

impedimetric sensor; self assembled monolayer; lead; modified gold electrode

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