Development of Potentiometric Phenol Sensors by Nata de Coco Membrane on Screen-Printed Carbon Electrode.

Nata de coco, a bacterial cellulose as a result of coconut water fermentation, is a conductive polymer with a electrical conductivity of 553 S/cm and has high mechanical stability. In this study, nata de coco was used as a supporting membrane for the development of phenol sensors in potentiometry. Nata de coco membrane containing phenol is coated on the surface of the printed carbon electrode (screen-printed carbon electrode). The cross-sectional area of the carbon electrode coated with the membrane is 1.5 × 3 mm, while the reference electrode is Ag/AgCl. The thickness of the electrode membrane affects the Nernstian factor. The optimum Nernstian factor is produced by 100 m membrane thickness containing 117.5 g of phenol. Measurement of phenol solution was carried out at pH 11, in the concentration range of 10 to 10 mol/L, resulting in a Nernstian factor of 41.8 ± 1.3 mV/decade. The Nernstian factor increased to 55.7 ± 0.4 mV/decade if the membrane of the electrode contained 0.1% FeO nanoparticles. This sensor has been applied in the real sample of river water, resulting in good accuracy and precision.