This critical review focuses on the development of anion sensors, being either fluorescent and/or colorimetric, based on the use of the 1,8-naphthalimide structure; a highly versatile building unit that absorbs and emits at long wavelengths. The review commences with a short description of the most commonly used design principles employed in chemosensors, followed by a discussion on the photophysical properties of the 4-amino-1,8-naphthalimide structure which has been most commonly employed in both cation and anion sensing to date. This is followed by a review of the current state of the art in naphthalimide-based anion sensing, where systems using ureas, thioureas and amides as hydrogen-bonding receptors, as well as charged receptors have been used for anion sensing in both organic and aqueous solutions, or within various polymeric networks, such as hydrogels. The review concludes with some current and future perspectives including the use of the naphthalimides for sensing small biomolecules, such as amino acids, as well as probes for incorporation and binding to proteins; and for the recognition/sensing of polyanions such as DNA, and their potential use as novel therapeutic and diagnostic agents (95 references).

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Colorimetric and fluorescent anion sensors: an overview of recent developments in the use of 1,8-naphthalimide-based chemosensors

Applications of Supramolecular Anion Recognition

The present critical review outlines the close relationship and mutual interplay between molecular recognition, active site considerations in enzyme catalysis involving anions, and organocatalysis utilizing explicit hydrogen bonding. These interconnections are generally not made although, as we demonstrate, they are quite apparent as exemplified with pertinent examples in the field of (thio)urea organocatalysis. Indeed, the concepts of anion binding or binding with negatively (partially) charged heteroatoms is key for designing new organocatalytic transformations. Utilizing anions through recognition with hydrogen-bonding organocatalysts is still in its infancy but bears great potential. In turn, the discovery and mechanistic elucidation of such reactions is likely to improve the understanding of enzyme active sites (108 references).

(Thio)urea organocatalysis—What can be learnt from anion recognition?

Detection Ying Zhou,†,‡ Jun Feng Zhang, and Juyoung Yoon*,† †Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Korea ‡Key Laboratory of Medicinal Chemistry for Natural Resource, School of Chemical Science and Technology, Yunnan University, Kunming, 650091, P. R. China College of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650500, P. R. China

Fluorescence and colorimetric chemosensors for fluoride-ion detection.

Recent Advances in Supramolecular Analytical Chemistry Using Optical Sensing.

The elucidation of phospholipid bilayer-small molecule interactions using a combination of phospholipid nanodiscs and solution state NMR techniques.

Small neutral molecular carriers for selective carboxylate transport

Amyloid seeds are nanometre-sized protein particles that accelerate amyloid assembly, as well as propagate and transmit the amyloid protein conformation associated with a wide range of protein misfolding diseases. However, seeded amyloid growth through templated elongation at fibril ends cannot explain the full range of molecular behaviours observed during cross-seeded formation of amyloid by heterologous seeds. Here, we demonstrate that amyloid seeds can accelerate amyloid formation via a surface catalysis mechanism without propagating the specific amyloid conformation associated with the seeds. This type of seeding mechanism is demonstrated through quantitative characterisation of the cross-seeded assembly reactions involving two non-homologous and unrelated proteins: the human A{beta}42 peptide and the yeast prion-forming protein Sup35NM. Our results suggest experimental approaches to differentiate seeding by templated elongation from non-templated amyloid seeding, and rationalise the molecular mechanism of the cross-seeding phenomenon as a manifestation of the aberrant surface activities presented by amyloid seeds as nanoparticles.

/pdf/amyloid-particles-facilitate-surface-catalyzed-cross-seeding-4ua6exuxfa.pdf

Amyloid particles facilitate surface-catalyzed cross-seeding by acting as promiscuous nanoparticles

A series of carbazolylurea- and carbazolylthiourea-based receptors have been synthesised and their anion complexation and fluorescence properties were studied. The urea compounds show selectivity for oxo-anion complexation over chloride and the fluorescence of compound 1 is selectively quenched by benzoate anions in DMSO/0.5% water. However, the thiourea compounds show reduced anion affinities compared to the urea analogues.

/pdf/fluorescent-carbazolylurea-and-carbazolylthiourea-based-1hmwh2632j.pdf

Fluorescent carbazolylurea- and carbazolylthiourea-based anion receptors and sensors

The chemical warfare agent (CWA) soman (GD) acts as a molecular stimulus for the disruption of an anthracene-based binary organogel prepared in cyclohexane. The CWA simulants dimethyl methylphosphonate (DMMP) and diethyl chlorophosphate (DCP) were also found to disrupt the binary organogel through changes in solvent polarity and reactions with the gelator.

Jennifer R. Hiscock

Papers

The elucidation of phospholipid bilayer-small molecule interactions using a combination of phospholipid nanodiscs and solution state NMR techniques.

Small neutral molecular carriers for selective carboxylate transport

Amyloid particles facilitate surface-catalyzed cross-seeding by acting as promiscuous nanoparticles

Fluorescent carbazolylurea- and carbazolylthiourea-based anion receptors and sensors

Disruption of a binary organogel by the chemical warfare agent soman (GD) and common organophosphorus simulants