## 1 Introduction  
Environmental analytical control requires the development of appropriate sensors that can perform rapid and reliable detection and identification of environmentally relevant chemical species. Among the wide variety of contaminants, the control of high-vapor-pressure toxic species in the form of volatile organic compounds (VOCs) is very important in occupational safety and health control (e.g., in workplace atmospheres) because they can produce harmful effects on human health. In this vein, acetone is an organic chemical compound found naturally in the environment, and due to its many versatile applications, is mass-produced in the industry. It is extensively used in laboratories and industrial applications. These industries include paint, plastic, artificial fiber, and shoe factories. Acetone is a volatile organic compound that evaporates quickly, remaining in the atmosphere for 15 to 60 days [1]. People working in industries that process and use acetone can be exposed to higher levels of this organic compound. While acetone levels below 100 ppm in air produce no effect, levels ranging between 200 and 500 ppm irritate the respiratory system, with 500 ppm being the maximum recommended 8 h occupational exposure level. Concentrations above these levels can produce different symptoms, including light-headedness, confusion, dizziness, and at high enough levels, could cause loss of consciousness [2]. It is therefore of utmost importance to have instruments that can continuously and accurately monitor the concentration levels of acetone present in gaseous media for safety purposes. The Occupational Safety and Health Administration (OSHA) provides a methodology for acetone quantification based on gas chromatography-flame ionization detection (GC-FID) [3], which is unsuitable for fast, in situ, and continuous measurements, just like the other most common techniques for acetone detection in the gas phase, which are based on mass spectrometry and gas chromatography. Frequently, such methods require complex and long-lasting sample pre-treatment steps. Compared with those traditional analytical methodologies, gas sensors have been acknowledged as simple and inexpensive tools for the detection and quantification of environmental toxins. Gas sensors are devices that are composed of active sensing materials coupled with a signal transducer. The selection and development of a potential sensing material that can be implemented in a low-cost, simple, and effective portable device for on-site and real-time analysis play an important role in designing high-performance gas sensors. Additionally, the measured signal is a key factor in the development of the prototype. In this sense, photoluminescence gas sensing approaches for the detection of organic molecules have demonstrated excellent performance for gas analysis [4]. In this context, improvements in nanotechnology have allowed for the development of nanomaterials with novel and improved optoelectronic properties. This strategy has allowed for replacing conventional organic phosphors and fluorophores with alternative advantageous luminescent nanomaterials, such as quantum dots (QDs), which have recently demonstrated their high potential in the development of novel luminescent bioanalytical methodologies [5]. QDs are semiconductor inorganic nanoparticles with diameters between 2 and 10 nm that have remarkable optical properties due to the quantum confinement effect that appears when the particles are smaller than their exciton Bohr radius [6; 7]. This is usually translated into high luminescence quantum yields, narrow photoluminescence emission, wide absorption spectra, and low photobleaching [8]. QDs' luminescence is strongly related to their surface state such that physicochemical interactions with other chemical species produce changes in the luminescent output. Using this property as the basis, many novel sensing approaches for the direct analysis of small molecules and ions have been developed.