Functionalized Nanomaterials to Sense Toxins/Pollutant Gases Using Perturbed Microwave Resonant Cavities

Abstract

This chapter provides an overview of the techniques and methods involving electromagnetic resonators to study the interactions of gas molecules with nanomaterials substrates. A resonant cavity operating in TE₀₁₁ mode was employed by the author(s) to characterize the nature of interactions of a range of weakly polar to nonpolar gas molecules with carbon nanotubes loaded in the cavity. Microwave resonant cavities are special electromagnetic resonators that can have a very high quality factor, which enhances the sensitivity of the apparatus as compared to standard electrical tank circuits. By measuring shifts in the resonant frequency of these circuits and by calculating the pressure broadening of the resonant peaks, the technique developed offers a highly effective means to quantify the amount of foreign agents perturbing these resonant cylinders. By functionalizing the nanomaterials with specific antibodies and loading them as wicks in these cylinders, the technique can be engineered into a very sensitive and unique chemical and biological sensor prototype.