Trends in sensor development

In appraising trends in some scientific or technical area, one usually tends to confuse the real and the ideal, i.e. what is being or will foreseeably be achieved and what is actually needed. This conflict also reaches what is discussed in this section, where the two sides are frequently mixed. There follows a description of major general trends in (bio)chemical sensors with explicit exclusion of those involving a specific group of sensor. 

As regards general technical features, (bio)chemical sensors will foreseeably result in increased automation, simplification and miniaturization, three of their inherent attributes (Fig. 1.8). Operationally, those features assuring quality in the results (Fig. 1.16.B), as well as others including durability, expeditiousness, robustness, cost-effectiveness, compatibility with complex samples, and ease of incorporation into portable analytical systems 

No doubt, computer science in general and chemometrics in particular offer a vast potential for Analytical Chemistry to dramatically raise the amount and quality of information that can be abstracted from raw data. The use of smart signal-processing systems is one of the more salient trends in the context of (bio)chemical sensors (Fig. 1.17.4). 

The most salient feature of flow-through sensors is the way in which the sample is brought into contact with the sensitive microzone (see Fig. 1.14), which distinguishes them from probe and drop-planar sensors. In fact, the liquid (or gaseous) sample is passed over the microzone rather than dropped onto it or used to immerse the probe [1]. 

In broad terms, a flow-through sensor is an analytical device consisting of an active microzone where one or more chemical or biochemical reactions, in addition to a separation process, can take place. The microzone is connected to or incorporated into an optical, electric, thermal or mass transducer and must respond in a direct, reversible, continuous, expeditious and accurate manner to changes in the concentrations of chemical or biochemical species in the liquid or gaseous sample that is passed over it, whether forcefully (by aspiration or injection) or otherwise (gases). 

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