Hierarchical Route for the Fabrication of Cavitand-Modified Nanostructured ZnO Fibers for Volatile Organic Compound Detection

Abstract

A hierarchical hybrid inorganic–organic system suited for the recognition of aromatic volatile organic compounds on brushlike ZnO fibers was synthetized. The hybrid material was obtained by a multistep approach based on the growth of ZnO nanorods onto electrospun ZnO fibers (average diameter 200 nm). The obtained nanostructured ZnO brushlike fibers (overall diameter 2 μm) were functionalized through the grafting of a bifunctional phosphonic linker (12-azidododecylphosphonic acid) followed by the anchoring of a specific cavitand receptor. The linker was anchored on ZnO fibers through the phosphonic group while the azide terminations reacted with a quinoxaline-bridged cavitand (QxCav) having four alkyne groups via “click” reaction. The anchoring steps were monitored through the evolution of the FT-IR features in the 3200–2800 cm–1 region due to C–H x stretches and in the 2200–2000 cm–1 region due to the azide and alkyne groups of the phosphonic linker and QxCav. The recognition properties of this hybrid nanostructure toward α,α,α-trifluorotoluene vapors were evaluated by XPS and Raman measurements.

Chemical Protection of Material Morphology: Robust and Gentle Gas-Phase Surface Functionalization of ZnO with Propiolic Acid

“…4 More recently, Tudisco et al obtained nanostructured ZnO fibers functionalized through the grafting of a bifunctional phosphonic linker with azide terminations, followed by the anchoring of a specific cavitand receptor having four alkyne groups via “click” reaction. 12 Although carboxylic and phosphonic acids do lead to the formation of stable linkages on ZnO surface, multiple species are always formed during the attachment process, which makes it difficult to apply further modification protocols to the resulting surfaces. More importantly, solution-based methods, despite sometimes being successful in applications to nanoparticles, alter the structures of thin films or nanostructured materials because ZnO is easily dissolved in a wide number of solvents and especially prone to dissolution in acids.…”

Size‐Selective Silver‐Induced Evolution of Mn3O4−Ag Nanocomposites for Effective Ethanol Sensing

“…However, to meet the growing number of clinical challenges, the advent of maneuvering new diagnostic and detection technologies have focused on nanomaterial‐based sensors for the detection of VOCs. During the last few years, organic, inorganic, and inorganic‐organic hybrid nanoscale semiconductors with wide band gap have received increased attention because of their high sensitivity and selectivity towards the detection of VOCs. Metal oxide semiconductors, such as, SnO 2 , In 2 O 3 , TiO 2 , ZnO, CuO, WO 3 and their composites have, often, been exploited as sensing materials of these harmful organic compounds at low concentrations .…”

Templating Porphyrin Anisotropy via Magnetically Aligned Carbon Nanotubes

“…For example, just as Nature seamlessly arranges the light harvesting (LH) antenna complex in order to accomplish its unique functions, chemists have devoted efforts in supramolecular association of fundamental molecular modules into functional materials . In fact, the controlled organization of photoactive molecules is playing a crucial role in the research and future development of devices, such as solar cells, organic transistors, chemical and bio‐sensors . The organization into functional nano‐architectures of chromophoric modules has been achieved either through non‐templated or templated methodologies .…”

“…[4][5][6][7][8][9][10][11][12][13] In fact, the controlled organization of photoactive molecules is playing a crucial role in the research and future development of devices, such as solar cells, [14,15] organic transistors, [16,17] chemical and bio-sensors. [18][19][20][21][22][23][24][25][26] The organization into functional nano-architectures of chromophoric modules has been achieved either through non-templated or templated methodologies. [27] In case of non-templated approaches, the various non-covalent interactions (i. e., H-bonds, transition metal coordination bonds, electrostatic interactions and others) have been exploited to build complex organic architectures featuring nanoscale precision and long-range order.…”