| Popis: |
Sensors of any kind are nowadays substantially ubiquitous with the aim of improving the quality of our lives in any technologically advanced application. Following a definition given by lUPAC, a sensor is a system that, stimulated by any form of energy, reacts changing its own state and thus one or more of its characteristics. Among the different kinds of sensors, chemical sensors, i.e., those sensors that transform chemical information (ranging from the concentration of a specific sample component to total composition analysis) into an analytically useful signal, are of particular importance.1 They have, in fact, already found a wide application in many fields, such as environmental monitoring, process control, food and beverage analysis, medical diagnosis, and, lately, toxic gases and explosives detection. It is evident that all these fields are of great importance from a social and an economical point of view. The development of chemical sensors seems thus predestined to revolutionise the potentialities of chemical analysis. Up to now the convenience of characterising from a chemical point of view an environment was strongly conditioned by many practical factors, mostly related to time and cost, and in many cases these two variables, in the final balance, could make this kind of analysis unsuitable or even useless.2 Classical methodologies require collection, transportation, eventual pretreating of the sample, and, in many cases, expensive instrumentation manageable only by trained personnel. Chemical sensory devices have been conceived to bypass these restrictions and cover a large field of applications where conventional strategies result to be, even when feasible, inadequate. Chemical sensors, however, are valuable not only since they are cheap and user-friendly analytical tools; they indeed offer more than this: if properly designed they allow monitoring analyte concentrations in real-time and real-space.3, 4, 5 |
