Selectivity and Specificity: Pros and Cons in Sensing

Abstract

Sensing using specific and selective receptors provides two very different but complementary strategies. This Sensor Issues article will discuss the merits and challenges of specific sensors, and selective sensors based on synthetic arrays. We will examine where each has been successfully applied to a sensing challenge, and then look at how a combined approach could take elements of both to provide new sensor platforms.

Keywords: antibodies; array-based sensing; chemical sensors; selectivity; specificity.

Figure 1

The transition from specific to selective sensing, and the corresponding outputs that are generated by sensor designs: (a) an antibody gives specific information about a single analyte, due to its high specificity. (b) Multiple analytes require different antibodies, leading to the creation of an antibody array in which each array component is only specific to a single analyte with no cross-reactivity. (c) Selective sensor arrays likewise give rise to unique patterns (fingerprints) for each analyte due to the cross-reactivity of the array components. (d) Hypothesis free, cross-reactive arrays enable the differentiation of multiple analytes, even those of different types (organic, inorganic etc.), with no previous knowledge needed. In all three of the multi-sensor platforms patterns are generated that can be analyzed to match against a known pattern using statistical methods.