RESUMO
To facilitate printable sensing solutions particles need to be suspended and stabilised in a liquid medium. Hansen parameters were used to identify that alcohol-water blends are ideal for stabilising colloidal copper hydroxide in dispersion. The suspended material can be further separated in various size fractions with a distinct cuboid geometry which was verified using atomic force microscopy. This facilitates the development of Raman spectroscopic metrics for determining particle sizes. This aspect ratio is related to the anisotropic crystal structure of the bulk crystallites. As the size of the nanocuboids decreases electrochemical sensitivity of the material increases due to an increase in specific surface area. Electrochemical glucose sensitivity was investigated using both cyclic voltammetry and chronoamperometry. The sensitivity is noted to saturate with film thickness. The electrochemical response of 253 mA M-1 cm-2 up to 0.1 mM and 120 mA cm-2 up to 0.6 mM allow for calibration of potential devices. These results indicate suitability for use as a glucose sensor and, due to the surfactant-free, low boiling point solvent approach used to exfoliate the nanocuboids, it is an ideal candidate for printable solutions. The ease of processing will also allow this material to be integrated in composite films for improved functionality in future devices.
Assuntos
Cobre/química , Eletroquímica/métodos , Glucose/análise , Hidróxidos/química , Nanoestruturas/química , Eletroquímica/instrumentação , Eletrodos , Limite de Detecção , Solventes/químicaRESUMO
A study of the composition of cell walls extracted from a wild strain and three mutant strains "smooth colony" of Saccharomyces cerevisiae had been done. It points out differences in the mannose/glucose ratio and in the concentration of some other components of the cell wall in the mutant strains. The immunological study of the cell wall shows that "smooth colonies" mutants and wild strains differs in their mannoproteins.