A novel bio-electronic tongue using different cellobiose dehydrogenases to resolve mixtures of various sugars and interfering analytes.

A novel application of cellobiose dehydrogenase (CDH) as sensing element for a Bioelectronic Tongue (BioET) system has been tested. In this work CDHs from various fungi, which exhibit different substrate specificities, were used to discriminate between lactose and glucose in presence of the interfering matrix compound Ca(2+) in various mixtures. This work exploits the advantage of an electronic tongue system with practically zero pre-treatment of samples and operation at low voltages in a direct electron transfer mode. The Artificial Neural Network (ANN) used in the BioET system to interpret the voltammetric data was able to provide a correct prediction of the concentrations of the analytes considered. Correlation coefficients in the comparison of obtained vs. expected concentrations were highly significant, especially for lactose (R(2)=0.975) and Ca(2+) (R(2)=0.945). This BioET application has a high potential especially for the food and dairy industry and also, if further miniaturised in screen printed format, for its in-situ use.

Pd nanoparticles/multiwalled carbon nanotubes electrode system for voltammetric sensing of tyrosine.

A facile and quick synthesis of palladium decorated multi-walled carbon nanotubes is presented in this work. The developed protocol allowed a quasi-homogeneous distribution of the metal nanoparticles on the surface of the nanotubes, and a controlled size of the nanoparticles in a range between 3.5 and 4.5 nm. After the characterization of the hybrid nanocomposite a first attempt on a possible application was made. The preliminary test, an ink-like nanocomposite as a modifier on the surface of a carbon screen-printed electrode, was performed in order to detect L-Tyrosine. Preliminary results are promising. A catalytic effect on the oxidation peak of the L-Tyrosine was shown and furthermore a low limit of detection, 1.46 x 10(-10) M, was reached.