Nanomaterials for cross-reactive sensor arrays

Arrays of cross-reactive sensors for the detection of multi-component chemical and biological agents have been actively developed during the past two decades. The rapid progress in this field has been driven by the need for fast online detection of a wide range of chemical and biological compounds and mixtures in different branches of industry and in medicine. Nanomaterials are ideal base materials for such sensor arrays because they are chemically versatile, can easily be fabricated, and can be integrated into existing sensing platforms to increase the sensitivity to the target agents. We present a concise though non-exhaustive didactic review of the main concepts and approaches related to the use of nanomaterials in cross-reactive sensor arrays. We focus on electronic transducers incorporating the most important classes of nanomaterials: molecularly modified metal nanoparticles, metal oxide nanoparticles, carbon nanotubes, and semiconducting nanowires. Selected examples of their integration into sensors and sensor arrays are given. We conclude with a brief discussion of the possibilities that the integration of the different types of nanomaterials into sensor arrays offer and the expected limitations.