Gas sensors with ZnO quantum dots synthetized by sol-gel methods

Abstract

Nanostructures are defined as having at least on dimension between 1 to 100 nm, with peculiar properties and applications, different from their bulk counterparts. ZnO nanostructures and their potential applications has been the focus of many scientific publications in the last decades. ZnO Quantum dots (QDs) are zero-dimensional (0D) structures with great interest of researchers since the 90s and keeping in view the quantization of electron energies in crystals and their transport properties. We studied the effective answers of chemical sensors made from ZnO nanoparticles, synthetized by Sol-Gel Method, for chloroform and ammonium vapors, very present in air conditioner, medical environments and beauty products, for example. These vapors are not toxic at low concentrations, but their increase can cause many health hazards to humans and animals. The results showed that ZnO Sol-Gel QDs sensor demonstrated, apparently, sensitivity to ammonia and no reaction with chloroform vapor. More tests should be conducted to evaluate the selectivity of these nanoparticles, including new tests with different crystallite sizes and structures, mainly seeking their application in several areas of Biomedical Engineering.