Flexible Polyester Screen‐printed Electrode Modified with Carbon Nanofibers for the Electrochemical Aptasensing of Cadmium (II)

Abstract An aptasensor was prepared by immobilising a biotinylated aptamer selected for Cd(II) on an activated carbon nanofiber (CNF) and streptavidin modified a screen‐printed electrode. The acid activated CNF was characterised by FTIR, CHNS elemental analysis and electron microscopy. Cyclic voltammetry, square wave voltammetry and electrochemical impedance spectroscopy (EIS) were used to characterise each step in the aptasensor preparation electrochemically. A detection limit of 0.11 ppb and a linear range of 2–100 ppb were obtained for Cd(II) with tolerance for other interfering species. The aptasensor was applied in real water samples and validated with ICPOES.