RICERCA ITALIANA     

Developement, characterisation, and analytical applications of innovative electrochemical sensors

Università degli Studi di Modena e Reggio Emilia

Abstract

The Project collects eight Units of Research, among which active collaborations in the field of Electroanalytical Chemistry have been active for a long time. The aim is to convey efforts towards the development of new electrochemical sensor systems for the analysis of compounds of interest in the field of food chemistry and for the in situ analysis of food matrices. The developed systems, consisting of modified electrodes, will be for the most part amperometric sensors, though attention will be also devoted to potentiometric sensors. The modifiers will be ion exchanger polymers, redox polymers and conducting polymers, permselective coatings, self assembled monolayers, multilayer polyelectrolytes, carbon nanotubes, metal oxides and metal nanoparticles, as such, as well as included inside conducting polymers. Some of these coatings will also be suitable for anchoring enzymes to the electrode. This constitutes a modern approach to the development of efficient biosensors.
The new sensors will be characterised as to all aspects necessary to define the principles on which they work, by using the wide number of techniques available to the Units of Research involved. Together with the more or less conventional electrochemical techniques, sophisticated spectroscopic techniques, as well as techniques for defining surface morphology, will be employed. Their measures will be often coupled to the suitable electrochemical ones. After testing on conventional-size electrodes, the >>>

Principal Investigator

Renato SEEBER Università degli Studi di MODENA e REGGIO EMILIA

Research Objectives

The Project of Research collects a significant number of Units of Research working in the field of Electroanalytical Chemistry in Italy. In particular, it involves groups that devoted in the past great attention to the characterisation of the analytical system considered from all points of view, not only as regards development of analytical methodologies in the strict meaning of the term. This means studying the way in which a system works, not only defining conditions and limits within which it works. Furthermore, attention has always been paid to developing of new systems, based on new materials and new technologies. To this purpose, the groups have arranged suitable interfaces on the one side with inorganic and organic chemists and, on the other side, with physicists and engineers.
The present Project aims at developing new electrochemical sensors, potentiometric and, most of all, amperometric sensors, as well as at characterising them from a structural and a morphological point of view, at understanding physical and chemical principles on which they actually work, at evaluating their performances. Design and development of such devices will be directed to use them with respect to analytes of interest in food chemistry, and directly on food matrices. Liquid, but also semi-liquid food materials will be considered.
Two different types of sensors will be taken into account. More precisely, both the way they are made and the way they work will point to two >>>

First Results

The first phase has to lead to precise formulation of systems suitable to specific determinations. This will introduce, in turn, to complete characterisation of the developed systems and to application of them to the study of synthetic and natural matrices. Since now on, it will be carefully considered that the final objective will consist of different food matrices, under liquid or semiliquid phase: from milk to fruit juice, from alcoholic beverages to fresh cheeses, to honey. The analytes considered, in view of the foodstuffs chosen, will be additives like dyes, anti-oxidants, preservatives, and some toxins, particularly mycotoxins.
The tests performed with single electrodes on synthetic matrices will lead to a first, though precise enough indication of the electrode systems that can be proposed in the frame of an ensemble for building up an artificial tongue. It is important to notice that it can be hypothesised that different ensembles will be identified as the most suitable ones in different situations. Only in a final stage the best compromise will be chosen.
From a chemometric point of view, the best experimental conditions will be identified, in order to obtain maximum information content from the employed sensors and, at the same time, the most promising algorithms will be tested and submitted to a final choice, in order to develop multivariate models, on the basis of the responses of the single sensors. The collected information will give elements for >>>

Timescale

24 months

National and international background

In the last years electroanalytical techniques have re-attracted most part of the great attention that was devoted to them in the first two decades after the Second World War, and that had then progressively faded. This happened for many reasons, which originated essentially from the strong increase of the potentialities of old and new spectroscopic and chromatographic analytical techniques. This led to a virtuous circle, which has led the producers to computerise efficiently the management of the measurements and to develop suitable software for treating the relevant signals. The use of these techniques became rapidly appealing and well user-friendly. Furthermore, the widespread diffusion of the spectroscopic and chromatographic instrumentation allowed the relevant costs to decrease. On the other hand, also due to the instrumental development of these techniques, the approach to electroanalytical techniques became comparably more difficult and almost suspicious: the supplier of electrochemical instrumentation could not invest enough money in research and development to allow them to compete successfully. As a conclusion, who needed analytical determinations barely considered the possibility to use electrochemical methodologies. In recent times, the availability of electrochemical instrumentation equipped with suitable software allowed the use of electrochemical techniques to those who estimated their execution and the evaluation of the results obtained too cumbersome. At >>>