Supramolecular fluorescence sensor for liquefied petroleum gas

Abstract

Sensing systems of nonpolar gas molecules without functional groups such as natural gas and liquefied petroleum gas (LPG) remain difficult to develop because of lacking selective detection of such molecules over other gas molecules. Here we report a supramolecular fluorescence sensor for LPG using a 2-nm-sized cube-shaped molecular container i.e. a nanocube self-assembled from six molecules of gear-shaped amphiphiles (GSA) in water. The nanocube selectively encapsulates LPG, while it does not bind other gas molecules. Upon encapsulation of LPG in the nanocube, the fluorescence from the nanocube is enhanced by 3.9 times, which is caused by the restricted motion of the aromatic rings of GSA in the nanocube based on aggregation-induced emission. Besides the high selectivity, high sensitivity, quick response, high stability of the nanocube for LPG, and easy preparation of GSA satisfy the requirement for its practical use for an LPG sensor.

Polarizability and isotope effects on dispersion interactions in water

“…The accumulation of multiple weak interactions give rise to great thermal stability of the nanocubes, which do not disassemble into the monomers at all at even higher temperature than the boiling point of water 17 . These stable nanocubes are attractive for their use towards molecular functions 20,21,22 , but their extremely high stability prevents us from determining the thermodynamic parameters for the self-assembly of the nanocubes to precisely discuss the effect of the weak intermolecular interactions. To slightly decrease the stability of the nanocube, we designed GSAs where a methoxy group is introduced on the periphery of the hexaphenylbenzene (HPB) core ( Fig.…”

A Molecular Capsule with Revolving Doors Partitioning Its Inner Space

“…[6] In fact, such fundamental studies could give rise to novel information processing devices [7] and chemosensors [8] as well as drug delivery,s equestration [9] and protein assembly modules. [10] To examinet he characteristics of guests sharing ac onfined space,o ne typically employs:( a) capsules assembled via noncovalenti nteractions [11] or held with transition metals, [12] (b) foldamers, [13] (c) macrocyclic cucurbit [8]urils, [5a] (d) calixarene-or resorcinarene-based capsules [14] or (e) 3D porousc rystals. [15] In all of these cases, aw ell-defined chamber brings complementary guests together to be in av an der Waals contact ( Figure 1A).…”

“…So far, holding multiple compounds in intimate contact has been of interest for examining encapsulation catalysis, [2] photochemical processes, [3] redox characteristics of molecules, [4] molecular recognition phenomena [5] as well as novel concepts in stereochemistry [6] . In fact, such fundamental studies could give rise to novel information processing devices [7] and chemosensors [8] as well as drug delivery, sequestration [9] and protein assembly modules [10] . To examine the characteristics of guests sharing a confined space, one typically employs: (a) capsules assembled via noncovalent interactions [11] or held with transition metals, [12] (b) foldamers, [13] (c) macrocyclic cucurbit[8]urils, [5a] (d) calixarene‐ or resorcinarene‐based capsules [14] or (e) 3D porous crystals [15] .…”

SO2 capture and detection with carbon microfibers (CMFs) synthesised from polyacrylonitrile

“…For example, Hiraoka and co-workers reported a functionalised organic nanotube with optimal selective fluorescence properties to detect liquefied petroleum gas. 11 Carbon materials have been explored for SO 2 capture. Yi et al, tested coconut shell-based activated carbon (SAC) and coal-based activated carbon (CAC), where SAC was the best adsorbent for SO 2 .…”