Sensor arrays for enology applicationsusing nanoscience for grape analysis

Resumen

This thesis tackles the development of new sensors based on different electroactive materials by means of different techniques. Different strategies have been foreseen to improve the performance and selectivity of the sensors by including enzymes and new electrocatalytic materials such as nanoparticles, phthalocyanines and different carbonaceous materials (microspheres, carbon nanotubes…). Efforts have been undertaken to develop new nanostructured and biomimetic biosensors that can improve the performance of the system. The behavior of different materials including graphene and Prussian blue as electron mediator in biosensors has been also tested. The modified electrodes showed an enhancement in the sensitivity and selectivity towards organic acids, phenolic compounds and sugars compare to classic electrodes. The use of Langmuir-Blodgett technique allowed preparing sensors presenting a nanostructure surface which was responsible of the improved electrochemical behavior towards the analysis of the target molecules (i.e. compare to non-nanostructured sensors). These new sensors have been combined to form arrays of sensors and biosensors applied for the enology industry. (Bio)electronic tongues have been applied to the discrimination of musts from different varities of grapes. In order to get information about the behavior of the electrodes, model solutions were analyzed previously to the samples. Besides the discrimination of grapes, a bioelectronic tongue containing enzymes devoted to the detection of phenols (tyrosinase and laccase) and sugars (glucose oxidase and D-fructose dehydrogenase) has been employed to monitor the ripening process of the grapes. These (bio)electronic tongues are a suitable alternative method of analysis for the winemaking industry since it leads to a general overview of the organoleptic characteristics of the sample, as panels of trained experts, and presents excellent correlations with the analytical parameters measured by traditional methods. The results presented on this Thesis have been reached on collaboration with researchers from UNESP (Brazil), BNL (USA) and Tokyo (Japan). Estación Enológica de Rueda, Instituto Tecnológico agrario de Castilla y León (ITACyL) and cellars of the región have also contributed to this work.