Structural Characterization of Graphene Nanosheets for Miniaturization of Potentiometric Urea Lipid Film Based Biosensors

The present article describes a miniaturized potentiometric urea lipid film based biosensor on graphene nanosheets. Structural characterization of graphene nanosheets for miniaturization of potentiometric urea lipid film based biosensors have been studied through atomic force microscopy (AFM) and transmission electron microscopy (TEM) measurements. UV-Vis and Fourrier transform IR (FTIR) spectroscopy have been utilized to study the pre- and postconjugated surfaces of graphene nanosheets. The presented potentiometric urea biosensor exhibits good reproducibility, reusability, selectivity, rapid response times (~4s), long shelf life and high sensitivity of ca. 70mV/decade over the urea logarithmic concentration range from 1×10 -6M to 1×10 -3M. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Potentiometric Cholesterol Biosensor Based on ZnO Nanowalls and Stabilized Polymerized Lipid Film

A novel potentiometric cholesterol biosensor was fabricated by immobilization of cholesterol oxidase into stabilized lipid films using zinc oxide (ZnO) nanowalls as measuring electrode. Cholesterol oxidase was incorporated into the lipid film prior polymerization on the surface of ZnO nanowalls resulting in a sensitive, selective, stable and reproducible cholesterol biosensor. The potentiometric response was 57mV/ decade concentration. The sensor response had no interferences by normal concentrations of ascorbic acid, glucose, and urea, proteins and lipids. The present biosensor could be implanted in the human body because of the biocompatibility of the lipid film. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim