From recent literature [1], electrospinning results to be one of the best tools, among the various nanotechnologies, for designing and developing smart sensing systems, both for the uniqueness of the resulting nanostructures and for production rate and cost. The use of electrospun fibers in photonics is a promising research field aimed at developing novel microscale optical sensors, that are generally appreciated for their high sensitivity, fast response time and low power consumption. Recently, very effective electrospun fluorescent fibers have been realized by using transparent or optically inert polymers properly doped with inorganic quantum dots [2]. The advantages of QDs over the traditional fluorescent molecules include high intensity of emission, good photostability, and long fluorescence lifetime. In the present study, titania nanofibrous layers decorated with fluorescent core/shell nanoparticles (QDs) have been designed ad investigated as potential optical sensors for detecting toxic gases in air (e.g. NH3). Initially, fluorescent (CdSe)ZnS core-shell quantum dots were synthesized, according to literature, [3] and then used to decor titania nanofibres according two strategies: the first one by drop-casting, the second one by chemical functionalization in situ. Their different arrangements over the fibres were characterized by AFM (Atomic Force Microscopy) and HR-TEM (High-Resolution Transmission Electron Microscopy), and their optical performances were investigated by spectrophotometry and spectrofluorometry as well as fluorescence microscopy. A very low cost and compact sensing device was designed and implemented (by a 3D-printer) to irradiate fibres (low power LED: 390 nm; 5 mW) and capture images (Raspicam digital camera). The luminance (PL) changes of the samples, before and after gas exposure, were measured through a developed software (by using Python). Effects of relative humidity and temperature were investigated too.
CdSe/ZnS-TiO2 nanofibers: a suitable combination for a low cost and effective sensor device
Emiliano Zampetti;Nicola Pirrone;Fabrizio De Cesare;Antonella Macagnano
2017
Abstract
From recent literature [1], electrospinning results to be one of the best tools, among the various nanotechnologies, for designing and developing smart sensing systems, both for the uniqueness of the resulting nanostructures and for production rate and cost. The use of electrospun fibers in photonics is a promising research field aimed at developing novel microscale optical sensors, that are generally appreciated for their high sensitivity, fast response time and low power consumption. Recently, very effective electrospun fluorescent fibers have been realized by using transparent or optically inert polymers properly doped with inorganic quantum dots [2]. The advantages of QDs over the traditional fluorescent molecules include high intensity of emission, good photostability, and long fluorescence lifetime. In the present study, titania nanofibrous layers decorated with fluorescent core/shell nanoparticles (QDs) have been designed ad investigated as potential optical sensors for detecting toxic gases in air (e.g. NH3). Initially, fluorescent (CdSe)ZnS core-shell quantum dots were synthesized, according to literature, [3] and then used to decor titania nanofibres according two strategies: the first one by drop-casting, the second one by chemical functionalization in situ. Their different arrangements over the fibres were characterized by AFM (Atomic Force Microscopy) and HR-TEM (High-Resolution Transmission Electron Microscopy), and their optical performances were investigated by spectrophotometry and spectrofluorometry as well as fluorescence microscopy. A very low cost and compact sensing device was designed and implemented (by a 3D-printer) to irradiate fibres (low power LED: 390 nm; 5 mW) and capture images (Raspicam digital camera). The luminance (PL) changes of the samples, before and after gas exposure, were measured through a developed software (by using Python). Effects of relative humidity and temperature were investigated too.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
