Chemical sensors and multisensor systems for potable water quality assessment and wine analysis

After the second half of the 20 century until today the development of chemical sensors has received considerable attention. The specific research awaits a requirement in various fields of quotidian life, such as industrial control, environmental monitoring, medicine, food production etc. Chemical sensors can be very effective in the circumstances in which the use of more accurate analytical methods and equipment it is hampered (due to sample pretreatment requirements, peculiarities analysis procedure, the need to use hazardous reagents and qualified personnel, etc.). Moreover, such devices do not require an expensive hardware, are portable, can be easily applied in field analysis, have low costs, are ease in manufacturing and handling and provide short response times. In recent years there have been amazing developments in chemical sensors and a large growth in their application. The modern chemical sensors are characterized by high sensitivity, low limits of detection (few ppb). The electronic tongue, a system consisting of a large number of detectors (synthetic sensing materials superimposed to a multisensory chips, or array of single chemical sensors) not specific but cross-sensitive, represent an example of what is the new orientation of analytical chemistry, and offer a tool able to reveal the different compounds in a fast, reliable and economic way. In this work, we have developed and applied different e-tongue systems, potentiometric and optical, employing familiar devices such as gadgets or other common equipment and not the expensive laboratory instrumentation for signal detection purpose. The developed e-tongue systems have also a benefit to be a non-invasive technique, which does not change the composition of the analysed sample (in comparison to other techniques where sample is irreversibly varied during the analysis, like in amperometric detection for instance) and is simple to use. Chapter I introduces the definition of chemical sensor, description of different sensors types and their working principles. Chapter II is devoted to the experimental details and setups, practical approaches, methods and techniques used in this work. Chapter III describes studies on the application of an potentiometric electronic tongue system for analysis of Italian wines. Chapter IV is dedicated to the implementation of potentiometric electronic tongue for environmental control, in particular for determination of pesticides and toxins in the water dedicated for human consumption. In Chapter V the development and application of optical chemical sensors and optical electronic tongue based on hydroxyquinoline-substituted diaza crown-ether fluorophores for magnesium determination are represented. The developed sensors were used then in the studies described in Chapter VI for the indirect determination of microcystin-LR toxin. Another array of optical sensors, colorimetric, based on porphyrins and pH indicators has been developed and applied for detecti