Ultrasensitive Detection of Volatile Organic Compounds by a Freestanding Aligned Ag/CdSe–CdS/PMMA Texture with Double-Side UV–Ozone Treatment

Abstract

Volatile organic compounds (VOCs) are organic chemicals having a high vapor pressure at room temperature. Chronic exposure to VOC vapor can be potentially dangerous to human health. In this study, we build a high-performance freestanding aligned Ag/CdSe–CdS/poly­(methyl methacrylate) (PMMA) texture to detect VOC vapors. The insight of this new VOC-sensing material is based on electrospinning techniques, ultraviolet (UV)/ozone treatments, and nano-optics. The incorporation of CdSe–CdS core–shell quantum rods (QR) and silver nanocrystals in the PMMA nanofibers amplifies the polarization response of long rods in VOC detection, thus increasing the sensitivity of VOC-sensing materials. Further, the uniaxial aligned Ag/QR/PMMA sensing material was treated by UV–ozone etching to increase surface absorption. The advanced double-sided UV–ozone etching on the uniaxial aligned Ag/QR/PMMA efficiently enhanced the extinction changes of VOCs. Two categories of solvents, typical VOCs and alcoholic VOCs, were put into practical tests for the Ag/QR/PMMA VOC-sensing materials. The Ag/QR/PMMA reached the detection limit for 100 ppm butanol within 1 min. The freestanding aligned Ag/CdSe–CdS/PMMA texture is a newly designed nanocomposite device for environmental risk monitoring. It can be accepted by the market compared to the other highly sensitive commercial VOC-sensing materials.

Highly-Sensitive Detection of Volatile Organic Compound Vapors by Electrospun PANI/P3TI/PMMA Fibers

“…When excess VOCs were loaded on the blending fibers, swelling occurred, and fibers collapsed. Interestingly, the solution parameters of 1-butanol and the PMMA matrix are close, contributing to the extinction change significantly [36].…”

“…It can be observed that the sensing fibers show a good response to n-butanol and DMF vapors. This is attributed to the formation of hydrogen bonding on the surface and the outstanding solubility of the conjugated polymer in DMF [36]. The extinction changes of the above VOC vapors are many times higher than the sensing noise signal (∆E = 0.001).…”

Transition metal sulfides meet electrospinning: versatile synthesis, distinct properties and prospective applications

“…Owing to the excellent surface stimulated PL properties of QDs, a large variety of optical sensors have been developed based on the PL improvement or quenching towards varied target molecules such as gases, anions, and cations. [135][136][137][138][139][140] On the other hand, 1D nanomaterials show the advantage of tight optical confinement, which provides the optical sensing with a larger sensitivity and higher response speed. Tong and co-workers have demonstrated that CdSe/ZnS QD dopants can be incorporated into PS electrospun nanofibers as an optical sensor for humidity detection (Figure 6a).…”

“…For instance, Ag nanoparticles and CdSe-CdS QDs have been embedded together into electrospun PMMA nanofibers to form a freestanding optical sensing material. 136 The detection limit to butanol was estimated to be 100 ppm with a response time lower than 1 min.…”

Electrospun SnO2/WO3 Heterostructure Nanocomposite Fiber for Enhanced Acetone Vapor Detection

“…Moreover, electrospinning allows for the incorporation of various functional materials into the nanofibers, such as polymers, composites, and nanoparticles, which can be precisely engineered to detect specific gases with high selectivity [31]. Our group has developed a series of electrospun-fiber-based materials for VOC sensing [32][33][34][35][36][37]. The mechanism of our sensing material is based on detecting the change in extinction that contributes to the collapse of the 3D fiber structure after VOC exposure.…”