Chemical Sensors and Biosensors: Fundamentals and Applications

Chapter 8

Nanomaterial Applications in Chemical Sensors

8.1 Generals

We are currently witnessing a remarkable revolution in various fields of science and technology as a result of the development of nanomaterials [1, 2]. This line of development has a considerable impact on the state-of-the-art of chemical sensors, and considerable progress in this area has already been achieved by the application of nanomaterials [3–6].

A nano-object is characterized by the fact that at least one of its dimension is within the nanometer scale, that is, < 10⁻⁶ m. From the standpoint of the macroscopic dimension, one can distinguish nanoparticles (zero-dimensional), nanowires (monodimensional) and nanosheets (two-dimensional) nanomaterials. Accordingly, none, one or two of these dimensions, respectively, are above the 10⁻⁶ m limit, the remaining dimensions falling within the nanometer range. Numerous biological entities, such as proteins, nucleic acids and viruses are within the nanosize scale and are often designated as biological nanomaterials. Synthetic nanomaterials of various chemical composition are currently available. Such nanomaterials may consist of pure chemical elements (metals, carbon or silicon), inorganic compounds (metal chalcogenides or metal oxides) or organic compounds (polymers).

What is characteristic of nanomaterials is that they normally display specific properties that are fundamentally different from the properties of the bulk material [7, 8]. In the case of metal and semiconductor ...