Cyclodextrins as eminent constituents in nanoarchitectonics for drug delivery systems

• Makoto Komiyama

Beilstein J. Nanotechnol. 2023, 14, 218–232, doi:10.3762/bjnano.14.21

• isomerization of azobenzene or its analogues is the most widely employed. CyD-based nanoarchitectures are sufficiently dynamic so that even these subtle molecular changes induce the dissociation of the whole nanoarchitecture for the release of the encapsulated drug. 2.1 Drug release from CyD-based

• nanoarchitectures through the isomerization of azobenzene Azobenzene isomerizes upon UV irradiation (around 300 nm) from the trans form to the cis form [47]. The reverse isomerization (from cis to trans) is accomplishable by light with longer wavelength (e.g., 400 nm). This isomerization is a notable structural

• change of the molecule and, thus, very useful to regulate the formation/deformation of supramolecular nanoarchitectures. Importantly, only trans-azobenzene can form inclusion complexes with CyD, since it has a straight and flat structure that fairly fits the cavity of CyD. In contrast, the cis isomer is

Impact of device design on the electronic and optoelectronic properties of integrated Ru-terpyridine complexes

• Max Mennicken,
• Sophia Katharina Peter,
• Corinna Kaulen,
• Ulrich Simon and
• Silvia Karthäuser

Beilstein J. Nanotechnol. 2022, 13, 219–229, doi:10.3762/bjnano.13.16

• plasmon-induced isomerization found in azobenzene derivatives used as ligands in nanoparticle arrays [41]. The conduction mechanism of the current contribution ΔIL_D is assumed to be hopping conduction since the charge carriers are mainly located in the ligand shell of the AuNP. Furthermore, the

The impact of molecular tumor profiling on the design strategies for targeting myeloid leukemia and EGFR/CD44-positive solid tumors

• Nikola Geskovski,
• Nadica Matevska-Geshkovska,
• Simona Dimchevska Sazdovska,
• Marija Glavas Dodov,
• Kristina Mladenovska and
• Katerina Goracinova

Beilstein J. Nanotechnol. 2021, 12, 375–401, doi:10.3762/bjnano.12.31

• NALM-6 cell membrane vesicles that were further decorated with aTGFβRII antibodies, attached via hypoxia-sensitive azobenzene linker. The membrane coating plays a dual role in the formulation. It guides the drug to the BM via receptor–ligand interaction between CXCR4 (a chemokine receptor expressed on

Multilayer capsules made of weak polyelectrolytes: a review on the preparation, functionalization and applications in drug delivery

• Varsha Sharma and
• Anandhakumar Sundaramurthy

Beilstein J. Nanotechnol. 2020, 11, 508–532, doi:10.3762/bjnano.11.41

• derivatives [62]. Photo-responsive and redox-responsive hydrogels of cyclodextrin with guest molecules of azobenzene and ferrocene have also been constructed [63]. Very few attempts have been made for fabrication of weak PE capsules under this category, as shown in Figure 3d [39]. Notably, the host and guest

Interfacial charge transfer processes in 2D and 3D semiconducting hybrid perovskites: azobenzene as photoswitchable ligand

• Nicole Fillafer,
• Tobias Seewald,
• Lukas Schmidt-Mende and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2020, 11, 466–479, doi:10.3762/bjnano.11.38

• ligands are influenced by the presence of a semiconductor and vice versa. Here ammonium-modified azobenzene compounds were selected as prototypes for molecular switches and organic–inorganic hybrid perovskites as semiconductor materials. The class of ammonium–lead–halide phases as prototypes is peculiar

• because, in addition to the surface functionalization of 3D crystals, organic compounds can actually be incorporated into the crystal as 2D phases. Thus, for example, layered Ruddlesden–Popper phases are obtained. We present photoswitchable azobenzene ligands with different head-group lengths for the

• -coordinated and integrated ligands between the perovskite layers. Photoswitching of azobenzene ligands incorporated in 2D phases is nearly quenched, while the same mechanism for surface-coordinating ligands is greatly improved, compared to the free ligands. The improvement originates from an energy transfer

Rational design of block copolymer self-assemblies in photodynamic therapy

• Maxime Demazeau,
• Laure Gibot,
• Anne-Françoise Mingotaud,
• Patricia Vicendo,
• Clément Roux and
• Barbara Lonetti

Beilstein J. Nanotechnol. 2020, 11, 180–212, doi:10.3762/bjnano.11.15

• hypoxia which acted on the azobenzene link between the hydrophobic and hydrophilic blocks. Imidazole groups are ROS-sensitive and can be oxidized into urea thus guaranteeing photosensitizer release in intracellular environment (Figure 5b) [75]. Covalent conjugation of photosensitizers As mentioned above

• chlorin-e6, an azobenzene group that can be cleaved at very low oxygen concentrations links the hydrophobic and the hydrophilic block. Upon irradiation and depletion of oxygen due to the PDT activity of chlorin-e6, the block copolymer nanovector disassembled and the anticancer drug, doxorubicin, was

• strong drawback for PDT but could be reversed towards an asset if the vector can be rendered sensitive to this. The study published by Zhao from 2018 is a typical example [75]. The vector consisted of PEO and PAsp (modified with imidazole moieties) blocks linked via an azobenzene group. Because this

Review of advanced sensor devices employing nanoarchitectonics concepts

• Katsuhiko Ariga,
• Tatsuyuki Makita,
• Masato Ito,
• Taizo Mori,
• Shun Watanabe and
• Jun Takeya

Beilstein J. Nanotechnol. 2019, 10, 2014–2030, doi:10.3762/bjnano.10.198

• stable state between the guest and host [181][182][183]. Shinkai and co-workers proposed a breakthrough approach to switch molecular recognition using photo-isomerization of an azobenzene moiety in a receptor structure (Figure 9) [184][185]. This mechanism creates two (or more) states with different

Recent highlights in nanoscale and mesoscale friction

• Andrea Vanossi,
• Dirk Dietzel,
• Andre Schirmeisen,
• Ernst Meyer,
• Rémy Pawlak,
• Thilo Glatzel,
• Marcin Kisiel,
• Shigeki Kawai and
• Nicola Manini

Beilstein J. Nanotechnol. 2018, 9, 1995–2014, doi:10.3762/bjnano.9.190

• azobenzene or spiropyran groups, should enable us to modify conformation, structure and chemical properties of the molecular layers on surfaces under photon irradiation. High-resolution force microscopy will provide detailed information about these conformation changes, and will allow us to understand this

Optical orientation of nematic liquid crystal droplets via photoisomerization of an azodendrimer dopant

• Sergey A. Shvetsov,
• Alexander V. Emelyanenko,
• Natalia I. Boiko,
• Alexander S. Zolot'ko,
• Yan-Song Zhang,
• Jui-Hsiang Liu and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2018, 9, 870–879, doi:10.3762/bjnano.9.81

• , Taiwan 10.3762/bjnano.9.81 Abstract Two sequential transformations of the orientational structure in nematic liquid crystal droplets containing a dendrimer additive (nanosized macromolecules with light-absorbing azobenzene terminal moieties) under light irradiation in the UV–blue spectral range were

• rearrangement of their azobenzene moieties, which is the key point in the explanation of the observed effects. Keywords: dendrimer; droplets; nematic liquid crystal; orientational transition; photo-orientation; Introduction Azobenzene compounds represent a very convenient tool for the development of

• returns into trans form. The anisotropic interaction of azobenzene molecules with each other, as well as with their environment, essentially depends on their shape (rod-like for trans isomers and having no distinct anisometry for cis isomers). This leads to the modification of physical properties of

Rigid multipodal platforms for metal surfaces

• Michal Valášek,
• Marcin Lindner and
• Marcel Mayor

Beilstein J. Nanotechnol. 2016, 7, 374–405, doi:10.3762/bjnano.7.34

• adamantane-based tripodal molecules have been reported by Yamakoshi and co-workers [83][90]. They designed and examined azobenzene-terminated tripodal derivatives 13 (Figure 5), which are suitable as a single-molecular tip for noncontact atomic force microscopy (NC-AFM). The reversible photoisomerisation of

• system based on an adamantane core unit with acetyl protected thiol anchoring groups and an azobenzene head-group was reported for the preparation of photochromic SAMs on gold surfaces [112]. Another type of rigid platform, based on the cyclohexyl-based tridental platform 22-Cn (Figure 10), was pioneered

Effects of electronic coupling and electrostatic potential on charge transport in carbon-based molecular electronic junctions

• Richard L. McCreery

Beilstein J. Nanotechnol. 2016, 7, 32–46, doi:10.3762/bjnano.7.4

• Figure 1, for the case of an azobenzene (AB) molecule covalently bonded to an edge site in a 9-ring graphene fragment, denoted “G9”. We described the rationale for investigating edge-bonding previously [2][34][42][43], and it is the most likely site in real devices. Since the carbon surface is disordered

• for both the strong electronic coupling and the excellent stability of carbon-based molecular junctions. The guidance provided by DFT illustrated here should prove useful for designing new MJ structures which exploit these properties. Structures of azobenzene (AB), 9-ring graphene fragment (G9), AB

• lengths from 0.2 to 5 nm. B) same data as panel A on a log scale. BTB = bis(thienyl)benzene, AN = 2-anthracene, AB = azobenzene, ethene = trans-oligoethenylenes, ethyne = oligoethynylenes, AQ = anthraquinone. A) Isolated AB and G9 molecules showing the calculated HOMO and LUMO energies relative to the

Light-powered, artificial molecular pumps: a minimalistic approach

• Giulio Ragazzon,
• Massimo Baroncini,
• Serena Silvi,
• Margherita Venturi and
• Alberto Credi

Beilstein J. Nanotechnol. 2015, 6, 2096–2104, doi:10.3762/bjnano.6.214

• nonsymmetric molecular axle, thus forming the basis for the development of artificial molecular pumps. Keywords: azobenzene; molecular machine; photochemistry; rotaxane; supramolecular chemistry; Review Introduction Since ancient times, man has tried to construct devices that facilitate life. With the advent

• , photosensitive azobenzene group (A), an ammonium ion that performs as the recognition site (R) for the macrocycle, and a nonphotoactive unit (S). Azobenzene, which is stable in its trans configuration, can be temporarily converted in a photochemical manner into the metastable cis isomer, endowed with

• because it is less hindered in comparison with the S unit. At this point, light irradiation in the ultraviolet or blue regions converts azobenzene into the cis form. This transformation causes, on the one hand, the destabilization of the pseudorotaxane by weakening the ring–axle interactions (increase of

Applications of three-dimensional carbon nanotube networks

• Manuela Scarselli,
• Paola Castrucci,
• Francesco De Nicola,
• Ilaria Cacciotti,
• Francesca Nanni,
• Emanuela Gatto,
• Mariano Venanzi and
• Maurizio De Crescenzi

Beilstein J. Nanotechnol. 2015, 6, 792–798, doi:10.3762/bjnano.6.82

• surface was estimated to be about 50 mW·cm−2 by azobenzene actinometry [30]. Photograph of a dish containing CNT-sponges, and two cut pieces of few cubic mm. SEM micrographs showing the entangled structure of the network acquired at two different magnifications (a,b). The red arrows in panel (b) point to

Non-covalent and reversible functionalization of carbon nanotubes

• Antonello Di Crescenzo,
• Valeria Ettorre and
• Antonella Fontana

Beilstein J. Nanotechnol. 2014, 5, 1675–1690, doi:10.3762/bjnano.5.178

• irradiation converts the dispersant into a cation with a superhydrophilic nature and thus more prone to interact with water than with the nanotube surface. The CNTs dispersing ability of azobenzene polymers is also tunable by the light-promoted trans–cis isomerization of azobenzene units that allow to switch

Direct monitoring of opto-mechanical switching of self-assembled monolayer films containing the azobenzene group

• Einat Tirosh,
• Enrico Benassi,
• Silvio Pipolo,
• Marcel Mayor,
• Michal Valášek,
• Veronica Frydman,
• Stefano Corni and
• Sidney R. Cohen

Beilstein J. Nanotechnol. 2011, 2, 834–844, doi:10.3762/bjnano.2.93

• Support, Rehovot Israel 10.3762/bjnano.2.93 Abstract The potential for manipulation and control inherent in molecule-based motors holds great scientific and technological promise. Molecules containing the azobenzene group have been heavily studied in this context. While the effects of the cis–trans

• bonds and from intermolecular interactions in the film. These results demonstrate the power and insights gained from cutting-edge AFM technologies, and advanced computational methods. Keywords: AFM; azobenzene; elastic modulus; molecular dynamics; nanomechanics; photoswitch; quantum mechanics

• computation; self-assembled monolayer; Introduction Molecule-based motors have great appeal due to their addressability, small size, and the possibility to incorporate them into unique structures. Molecules containing the azobenzene functionality are good candidates for converting light into mechanical work

Terthiophene on Au(111): A scanning tunneling microscopy and spectroscopy study

• Berndt Koslowski,
• Anna Tschetschetkin,
• Norbert Maurer,
• Elena Mena-Osteritz,
• Peter Bäuerle and
• Paul Ziemann

Beilstein J. Nanotechnol. 2011, 2, 561–568, doi:10.3762/bjnano.2.60

• lowest unoccupied molecular orbital (LUMO) of 3T. A preferential adsorption of the aromatic molecules in the fcc regions has also been observed for azobenzene [14], 1-nitronaphthalene [15][16], tetrathiafulvalene [17], and 9-aminoanthracene [18]. The tendency of the molecules to maximize the