A new approach to unlock highly efficient polymer solar cells is presented in article number 1606729 by Chang-Zhi Li, Junsheng Yu, and co-workers, in which two bulk heterojunction layers with complementary optoelectronic properties are vertically connected via a stamp-transfer method, and sandwiched between one set of cathode and anode for enabling over 12% power conversion efficiency.
High-efficiency small-molecule-based organic photovoltaics (SM-OPVs) using two electron donors (p-DTS(FBTTh2)2 and ZnP) with distinctively different absorption and structural features are reported. Such a combination works well and synergically improves device short-circuit current density (Jsc) to 17.99 mA cm−2 and fill factor (FF) to 77.19%, yielding a milestone efficiency of 11%. To the best of our knowledge, this is the highest power conversion efficiency reported for SM-OPVs to date and the first time to combine high Jsc over 17 mA cm−2 and high FF over 77% into one SM-OPV. The strategy of using multicomponent materials, with a selecting role of balancing varied electronic and structural necessities can be an important route to further developing higher performance devices. This development is important, which broadens the dimension and versatility of existing materials without much chemistry input.
High-efficiency all-small-molecule organic solar cells using two electron donors with distinctively different absorption and structural features are reported. Such a combination works well and synergically improves device current and fill factor, yielding a milestone efficiency of 10.97%.
A fused hexacyclic electron acceptor, IHIC, based on strong electron-donating group dithienocyclopentathieno[3,2-b]thiophene flanked by strong electron-withdrawing group 1,1-dicyanomethylene-3-indanone, is designed, synthesized, and applied in semitransparent organic solar cells (ST-OSCs). IHIC exhibits strong near-infrared absorption with extinction coefficients of up to 1.6 × 105m−1 cm−1, a narrow optical bandgap of 1.38 eV, and a high electron mobility of 2.4 × 10−3 cm2 V−1 s−1. The ST-OSCs based on blends of a narrow-bandgap polymer donor PTB7-Th and narrow-bandgap IHIC acceptor exhibit a champion power conversion efficiency of 9.77% with an average visible transmittance of 36% and excellent device stability; this efficiency is much higher than any single-junction and tandem ST-OSCs reported in the literature.
A fused hexacyclic electron acceptor with strong near-infrared absorption and high electron mobility is designed, synthesized, and applied in semitransparent organic solar cells, which exhibit a champion efficiency of 9.77% with an average visible transmittance of 36% and excellent device stability.
The chirality found in living organisms is one of unsolved mysteries on Earth. It is crucial to understand the manner in which small achiral molecules evolve into helical superstructures in the absence of chiral components because this process can provide important insights regarding the origin of chirality in nature. 1) the uncommon helical assembly of an achiral trigonal chromophore into helical nanostructures with aggregation-induced emission enhancement (AIEE) characteristics and 2) the tunability of the helical pitch and fluorescence intensity in response to light is reported. The Rietveld refinement of X-ray diffraction (XRD) patterns and the growth process suggest that a striking transformation from an achiral to an asymmetric molecule can occur as a result of specific interactions with certain solvents, presumably leading to the unique helical assembly. More importantly, exposure to UV or visible light promoted not only the formation of irregular helical structures with a wide range of pitch lengths but also an increase in fluorescence intensity.
The uncommon helical assembly of an achiral chromophore into fluorescent helical nanostructures in the absence of chiral components and the tunability of the helical pitch and fluorescence intensity in response to light are reported. A marked transformation from an achiral to an asymmetric molecule can occur as a result of specific interactions with certain solvents, presumably leading to the unique helical assembly.
Anionic surfactants are widely used in daily life and industries, but their residues can cause serious damage to the environment. The current detection methods for anionic surfactants suffer from various limitations and a new detection strategy is highly desirable. Based on 2-(2-hydroxyphenyl)benzothiazole fluorogen with aggregation-induced emission characteristics, we have developed a fluorescent probe HBT-C18 for selective and sensitive detection of anionic surfactants. By in situ formation of catanionic aggregates or micelles with anionic surfactants, the emission intensity of the HBT-C18 probe can increase with increasing keto/enol emission ratio through restriction of intramolecular motion and excited-state intramolecular proton-transfer mechanisms. The probe can also be used for wash-free imaging of bacteria enveloped by a negatively charged outer membrane. The results of this study provide a new strategy for sensitive detection of anionic surfactants and wash-free bacterial imaging.
Based on 2-(2-hydroxyphenyl)benzothiazole fluorogen with aggregation-induced emission (AIE) characteristics, a fluorescent light-up probe HBT-C18 has been developed for selective and sensitive detection of anionic surfactants by in situ formation of catanionic aggregates. The AIE-active probe can also be used for monitoring catanionic micelle formation process and wash-free bacterial imaging.
Conjugates between oligoprolines and sterically demanding perylene monoimides (PMIs) form hierarchical supramolecular self-assemblies. The influence of the length and stereochemistry at the attachment site between the peptide backbone and the chromophore on the self-assembly properties of the conjugates was explored. Comparison between oligoprolines bearing 4R- or 4S-configured azidoprolines (Azp) for the conjugation with the PMIs revealed that diastereoisomers with 4R configuration guide the self-assembly consistently better than conjugates with 4S configuration. Elongating the peptide chain beyond nine proline residues or introducing structural “errors”, by altering the absolute configuration of one stereogenic center at the outside of the functionalizable oligoproline helix, lowered the efficacy of self-assembly significantly, both in solution phase and in the solid state. The results showed how subtle structural modifications allow for tuning the self-assembly of chromophores and provided further design principles for the development of peptide–chromophore conjugates into nanostructured materials.
Length and orientation matters: The length and stereochemistry of conjugates between oligoprolines and sterically demanding perylene monoimides can be used to tune their supramolecular assembly properties (see figure). Structural errors are tolerated in the best performing conjugates.
We introduce monosaccharides as versatile water-soluble units to compatibilise supramolecular polymers based on the benzene-1,3,5-tricarboxamide (BTA) moiety with water. A library of monosaccharide-based BTAs is evaluated, varying the length of the alkyl chain (hexyl, octyl, decyl and dodecyl) separating the BTA and saccharide units, as well as the saccharide units (α-glucose, β-glucose, α-mannose and α-galactose). In all cases, the monosaccharides impart excellent water compatibility. The length of the alkyl chain is the determining factor to obtain either long, one-dimensional supramolecular polymers (dodecyl spacer), small aggregates (decyl spacer) or molecularly dissolved (octyl and hexyl) BTAs in water. For the BTAs comprising a dodecyl spacer, our results suggest that a cooperative self-assembly process is operative and that the introduction of different monosaccharides does not significantly change the self- assembly behaviour. Finally, we investigate the potential of post-assembly functionalisation of the formed supramolecular polymers by taking advantage of dynamic covalent bond formation between the monosaccharides and benzoxaboroles. We observe that the supramolecular polymers readily react with a fluorescent benzoxaborole derivative permitting imaging of these dynamic complexes by confocal fluorescence microscopy.
Sugar-coating BTAs: Functionalising the periphery of benzene-1,3,5-tricarboxamide (BTA) with monosaccharides affords high aspect ratio supramolecular polymers in water, which are readily post-modified using benzoxaboroles by dynamic covalent chemistry (see figure).
The high-yielding synthesis of 2-substituted benzo-1,3-tellurazoles and benzo-1,3-selenazoles through a dehydrative cyclization reaction has been reported, giving access to a large variety of benzo-1,3-chalcogenazoles. Exceptionally, these aromatic heterocycles proved to be very stable and thus very handy to form controlled solid-state organizations in which wire-like polymeric structures are formed through secondary N⋅⋅⋅Y bonding interactions (SBIs) engaging the chalcogen (Y=Se or Te) and nitrogen atoms. In particular, it has been shown that the recognition properties of the chalcogen centre at the solid state could be programmed by selectively barring one of its σ-holes through a combination of electronic and steric effects exerted by the substituent at the 2-position. As predicted by the electrostatic potential surfaces calculated by quantum chemical modelling, the pyridyl groups revealed to be the stronger chalcogen bonding acceptors, and thus the best ligand candidate for programming the molecular organization at the solid state. In contrast, the thiophenyl group is an unsuitable substituent for establishing SBIs in this molecular system as it gives rise to chalcogen–chalcogen repulsion. The weaker chalcogen donor properties of the Se analogues trigger the formation of feeble N⋅⋅⋅Se contacts, which are manifested in similar solid-state polymers featuring longer nitrogen–chalcogen distances.
Building benzo-1,3-chalcogenazoles: A versatile four-step synthesis of 2-substituted benzo-1,3-selenazoles and -tellurazoles starting from 2-bromoaniline is reported (see figure; R=alkyl, alkenyl, phenyl, furanyl, thiophenyl, pyridyl and ferrocenyl groups). The solid-state arrangement shows that, depending on the electronic and geometrical properties of the substituent at the 2-position, one can control the wiring organization through two- (X⋅⋅⋅Y) or three-atoms (X⋅⋅⋅Y⋅⋅⋅X) secondary bonding interactions.
Native α-cyclodextrin- (α-CD) and permethylated α-CD (PMeCD)-based rotaxanes with various short alkylene chains as axles can be synthesized through a urea end-capping method. Native α-CD tends to form [3]- or [5]pseudorotaxanes and not [2]- or [4]pseudorotaxanes, which indicates that the coupled CDs act as a single fragment. End-capping reactions of the pseudorotaxanes with C18 and C24 axle lengths do not occur because the axle termini are covered by the densely stacked CDs. The number of PMeCDs on the pseudorotaxane is flexible and mainly depends on the axle length. Peracetylated α-CD (PAcCD)-based rotaxanes are synthesized through O-acetylation of the α-CD-based rotaxanes without any decomposition of the rotaxanated structures. The structures of PMeCD-based [3]- and [4]rotaxanes, and the molecular dynamics calculations on [3]pseudorotaxanes, indicate that the tail face of PMeCDs is regularly directed toward the axle termini. On the basis of the results obtained, it can be concluded that the directions and numbers of CDs in rotaxanes containing short alkylene chains depend on 1) the interactions between CDs, 2) the length of the alkylene axle, and 3) the interactions between the axle end and tail face of the CD.
Come on in! Native and permethylated α-cyclodextrin (CD)-based rotaxanes with various short alkylene axles are synthesized with a urea end-capping method. The directions and number of the CD wheels depend on the interactions between CDs, the axle length, and the interactions between axle ends and the tail face of the CDs (see figure).
The synthesis of boron difluoride complexes of a series of curcuminoid derivatives containing various donor end groups is described. Time-dependent (TD)-DFT calculations confirm the charge-transfer character of the second lowest-energy transition band and ascribe the lowest energy band to a “cyanine-like” transition. Photophysical studies reveal that tuning the donor strength of the end groups allows covering a broad spectral range, from the visible to the NIR region, of the UV–visible absorption and fluorescence spectra. Two-photon-excited fluorescence and Z-scan techniques prove that an increase in the donor strength or in the rigidity of the backbone results in a considerable increase in the two-photon cross section, reaching 5000 GM, with predominant two-photon absorption from the S0–S2 charge-transfer transition. Direct comparisons with the hemicurcuminoid derivatives show that the two-photon active band for the curcuminoid derivatives has the same intramolecular charge-transfer character and therefore arises from a dipolar structure. Overall, this structure–relationship study allows the optimization of the two-photon brightness (i.e., 400–900 GM) with one dye that emits in the NIR region of the spectrum. In addition, these dyes demonstrate high intracellular uptake efficiency in Cos7 cells with emission in the visible region, which is further improved by using porous silica nanoparticles as dye vehicles for the imaging of two mammalian carcinoma cells type based on NIR fluorescence emission.
Very bright: The influence of different donor (D) and acceptor (A) groups of boron difluoride complexes containing curcuminoid derivatives on the UV/Vis absorption and fluorescence behavior is investigated by using experimental and theoretical methods. Selected compounds for also investigated as cell imaging probes (see figure).
The chiral stereoisomers of new non-ionic dendritic amphiphiles self-assemble in aqueous solution towards helical ribbons with opposite handedness. However, in the case of the meso-compound, cylindrical assemblies are observed, as illustrated. Modelling suggests that they consist of right- or left-handed helical molecular strands in equal distribution. The hydrophobic core of such a cylinder is sized to accommodate the hydrophobic tails. Only the head groups and the aromatic platforms, which contribute high density in transmission electron microscopy (TEM), are shown for clarity. The paper discusses stereochemical aspects upon supramolecular assembly of these new dendritic amphiphiles. More information can be found in the Full Paper by C. Böttcher, et al. (DOI: 10.1002/chem.201504504).
Speed, resolution and sensitivity of today's fluorescence bioimaging can be drastically improved by fluorescent nanoparticles (NPs) that are many-fold brighter than organic dyes and fluorescent proteins. While the field is currently dominated by inorganic NPs, notably quantum dots (QDs), fluorescent polymer NPs encapsulating large quantities of dyes (dye-loaded NPs) have emerged recently as an attractive alternative. These new nanomaterials, inspired from the fields of polymeric drug delivery vehicles and advanced fluorophores, can combine superior brightness with biodegradability and low toxicity. Here, we describe the strategies for synthesis of dye-loaded polymer NPs by emulsion polymerization and assembly of pre-formed polymers. Superior brightness requires strong dye loading without aggregation-caused quenching (ACQ). Only recently several strategies of dye design were proposed to overcome ACQ in polymer NPs: aggregation induced emission (AIE), dye modification with bulky side groups and use of bulky hydrophobic counterions. The resulting NPs now surpass the brightness of QDs by ≈10-fold for a comparable size, and have started reaching the level of the brightest conjugated polymer NPs. Other properties, notably photostability, color, blinking, as well as particle size and surface chemistry are also systematically analyzed. Finally, major and emerging applications of dye-loaded NPs for in vitro and in vivo imaging are reviewed.
Dye-loaded polymer nanoparticles have emerged recently as an attractive alternative to quantum dots and conjugated polymer nanoparticles in fluorescence bioimaging. Design concepts of bright and small nanoparticles with minimized dye self-quenching are summarized, their properties are analyzed systematically, and their major and emerging applications in cells and small animals are described.
Efficient morphology modulation of a red AIEgen from pristine microsized rods to nanospheres is achieved via encapsula ting QM-2 (quinolinemalononitrile-2) into hybrid micelles. This novel reagent shows great potential in tumor-targeted bioimaging because of its monodispersion in aqueous systems, the uniform diameter of ≈30 nm, enhanced fluorescence brightness with a large Stokes shift of 190 nm, and strongly increased biocompatibility and photostability.
Amphiphilic Janus particles are successfully obtained via a powerful strategy combining diffusion-induced phase separation and magnetically driven dewetting. A large-area, amphiphilic monolayer is been formed via a self-assembly paradigm based on a synergy between the amphiphilicity, shape anisotropy, and external magnetic field. This functionality holds great promise for practical applications in intelligent coatings, anti-bioadhesion, and antifouling surfaces.
3D carbon superstructures are fabricated through the hierarchical assembly of polyimide nanosheets and thermal treatment. Benefiting from the ultrahigh surface area and the hierarchically porous structure, along with the well-distributed highly electroactive sites, the flower-like carbon material exhibits outstanding catalytic activity toward the oxygen reduction reaction and also serves as a highly stable electrode material in supercapacitors.
Colloidal nanocrystals have been intensively studied over the past three decades due to their unique properties that originate, in large part, from their nanometer-scale sizes. For applications in electronic and optoelectronic devices, colloidal nanoparticles are generally employed as assembled nanocrystal solids, rather than as individual particles. Consequently, tailoring 2D patterns as well as 3D architectures of assembled nanocrystals is critical for their various applications to micro- and nanoscale devices. Here, recent advances in the designed assembly, film fabrication, and printing/integration methods for colloidal nanocrystals are presented. The advantages and drawbacks of these methods are compared, and various device applications of assembled/integrated colloidal nanocrystal solids are discussed.
The preparation, formatting, and applications of colloidal nanoparticle solids have burgeoned tremendously over the last thirty years due to the remarkable crossover of ideas from many materials science fields. Here, general information on the preparation of colloidal nanocrystalline solids via thin-film formation and various printing techniques is presented. In addition, their integration into a number of advanced electronic applications is discussed.
A chiral logic circuit is proposed based on the multiple chiroptical responsiveness of a supramolecular gel material. The gel is fabricated by mixing a chiral gelator and a spiropyran derivative. Chiral responsiveness including the chiral switch and the logic gate is realized through the combined chirality transfer, photochromism, and acidichromism of the system.
The equilibrium crystal shape and shape evolution of organic crystals are found to follow the Gibbs–Curie–Wulff theorem. Organic crystals are grown by the physical vapor transport technique and exhibit exactly the same shape as predicted by the Gibbs–Curie–Wulff theorem under optimal conditions. This accordance provides concrete proof for the theorem.
Bolaamphiphilic naphthalene-diimide conjugates exhibit favourable photophysical properties and self-assemble to form vesicular structures in water. These structures encapsulate hydrophobic molecules and show disassembly in the presence of DNA. This unique morphological transformation can be utilized to carry and release guest molecules controlled by DNA stimuli. For more details, see the Full Paper by D. Ramaiah and co-workers on page 17657 ff.
One-dimensional nanostructures with aggregation-induced emission (AIE) properties have been fabricated to keep the pace with growing demand from optoelectronics applications. The compounds 2-[4-(4-methylpiperazin-1-yl)benzylidene]malononitrile (PM1), 2-{4-[4-(pyridin-2-yl)piperazin-1-yl]-benzylidene}malononitrile (PM2), and 2-{4-[4-(pyrimidin-2-yl)piperazin-1-yl]benzylidene}malononitrile (PM3) have been designed and synthesized by melding piperazine and dicyanovinylene to investigate AIE in an asymmetric donor–acceptor (D–A) construct of A′–D–π–A- topology. The synthetic route has been simplified by using phenylpiperazine as a weak donor (D), dicyanovinylene as an acceptor (A), and pyridyl/pyrimidyl groups (PM2/PM3) as auxiliary acceptors (A′). It has been established that A′ plays a vital role in triggering AIE in these compounds because the same D–A construct led to aggregation-caused quenching upon replacing A′ with an electron-donating ethyl group (PM1). Moreover, the effect of restricted intramolecular rotation and twisted intramolecular charge transfer on the mechanism of AIE has also been investigated. Furthermore, it has been clearly shown that the optical disparities of these A′–D–π–A architectures are a direct consequence of comparative A′ strength. Single-crystal X-ray analyses provided justification for role of intermolecular interactions in aggregate morphology. Electrochemical and theoretical studies affirmed the effect of the A′ strength on the overall properties of the A′–D–π–A system.
Emission conditions: Three compounds have been designed and synthesized to investigate aggregation-induced emission (AIE) in an asymmetric donor–acceptor (D–A) construct of A′–D–π–A (A′=auxiliary acceptor) topology. The occurrence of AIE and subsequent optical disparities of these A′–D–π–A architectures are a direct consequence of the comparative strength of A′ (see figure).
The work presented herein is devoted to the fabrication of large Stokes shift dyes in both organic and aqueous media by combining dark resonance energy transfer (DRET) and fluorescence resonance energy transfer (FRET) in one donor–acceptor system. In this respect, a series of donor–acceptor architectures of 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) dyes substituted by one, two, or three tetraphenylethene (TPE) luminogens were designed and synthesised. The photophysical properties of these three chromophore systems were studied to provide insight into the nature of donor–acceptor interactions in both THF and aqueous media. Because the generation of emissive TPE donor(s) is strongly polarity dependent, due to its aggregation-induced emission (AIE) feature, one might expect the formation of appreciable fluorescence emission intensity with a very large pseudo-Stokes shift in aqueous media when considering FRET process. Interestingly, similar results were also recorded in THF for the chromophore systems, although the TPE fragment(s) of the dyes are non-emissive. The explanation for this photophysical behaviour lies in the DRET. This is the first report on combining two energy-transfer processes, namely, FRET and DRET, in one polarity-sensitive donor–acceptor pair system. The accuracy of the dark-emissive donor property of the TPE luminogen is also presented for the first time as a new feature for AIE phenomena.
Don’t FRET, DRET! An approach is presented to create energy-transfer systems that generate a remarkable large pseudo-Stokes shift with high emission intensity in both organic and aqueous media by combining dark resonance energy transfer (DRET) and fluorescence resonance energy transfer (FRET) in one donor–acceptor system (see figure).
Supramolecular polymers are a class of macromolecules stabilized by weak non-covalent interactions. These self-assembled aggregates typically undergo stimuli-induced reversible assembly and disassembly. They thus hold great promise as so-called functional materials. In this work, we present the design, synthesis, and responsive behavior of a short supramolecular oligomeric system based on two hetero-complementary subunits. These “monomers” consist of a tetrathiafulvalene-functionalized calix[4]pyrrole (TTF-C[4]P) and a glycol diester-linked bis-2,5,7-trinitrodicyanomethylenefluorene-4-carboxylate (TNDCF), respectively. We show that when mixed in organic solvents, such as CHCl3, CH2ClCH2Cl, and methylcyclohexane, supramolecular aggregation takes place to produce short oligomers stabilized by hydrogen bonding and donor–acceptor charge-transfer (CT) interactions. The self-associated materials were characterized by 1H NMR and UV/Vis/NIR absorption spectroscopy, as well as by concentration- and temperature-dependent absorption spectroscopy and dynamic light scattering (DLS) analyses of both the monomeric and oligomerized species. The self-associated system produced from TTF-C[4]P and TNDCF exhibits a concentration-dependent aggregation behavior typical of supramolecular polymers. Further support for the proposed self-assembly came from theoretical calculations. The fluorescence emitting properties of TNDCF are quenched under conditions that promote the formation of supramolecular aggregates containing TTF-C[4]P and TNDCF. This quenching effect has been utilized as a probe for the detection of substrates in the form of anions (i.e., chloride) and nitroaromatic explosives (i.e., 1,3,5-trinitrobenzene). Specifically, the addition of these substrates to mixtures of TTF-C[4]P and TNDCF produced a fluorescence “turn-on” response.
Explosive fluorescence: The hetero-complementary monomeric subunits, tetrathiafulvalene–calix[4]pyrrole (TTF-C[4]P) and bis-2,5,7-trinitrodicyanomethylenefluorene-4-carboxylate (TNDCF), assemble to form oligomeric structures at higher concentrations. Dual-analyte-responsive behavior is seen, with de-aggregation of the supramolecular oligomers and a corresponding increase in the fluorescence intensity being seen in the presence of 1,3,5-trinitrobenzene (TNB) or Cl− anions.
A 1,8-naphthalimide derivative that forms a stable hydrogel with very low critical gelation concentration is reported by Y. Zhao and co-workers. By taking advantage of the host–guest interaction, the complexation of this compound with cucurbit[8]uril leads to the formation of nanovesicles on page 5901. A cytotoxicity assay with cancer cells confirms that doxorubicin-loaded hydrogel and nanovesicles are effectively endocytosed by cancer cells, showing therapeutic effects. This work provides a strategy in the development of multiple drug nanocarriers from amphiphilic assemblies.
A joint experimental and computational study is reported on the concentration-dependant self-assembly of a flat C3-symmetric molecule on a graphite surface. As a model system a tripodal molecule, 1,3,5-tris(pyridin-3-ylethynyl)benzene, has been chosen, which can adopt either C3h or Cs symmetry when planar, as a result of pyridyl rotation along the alkynyl spacers. Density functional theory (DFT) simulations of 2D nanopatterns with different surface coverage reveal that the molecule can generate different types of self-assembled motifs. The stability of fourteen 2D patterns and the influence of concentration are analyzed. It is found that ordered, densely packed monolayers and 2D porous networks are obtained at high and low concentrations, respectively. A concentration-dependent scanning tunneling microscopy (STM) investigation of this molecular self-assembly system at a solution/graphite interface reveals four supramolecular motifs, which are in perfect agreement with those predicted by simulations. Therefore, this DFT method represents a key step forward toward the atomically precise prediction of molecular self-assembly on surfaces and at interfaces.
A concentration-dependent scanning tunneling microscopy investigation of the self-assembly of C3-symmetric molecule at a graphite/solution interface, collaborated with density functional theory calculations reveals the formation of four distinct supramolecular motifs.
Ever since the discovery of graphene, increasing efforts have been devoted to the use of this stellar material as well as the development of other graphene-like materials such as thin-layer transition metal dichalcogenides and oxides (TMD/Os) for a variety of applications. Because of their large surface area and unique optical properties, these two-dimensional materials with a size ranging from the micro- to the nanoscale have been employed as the substrate to construct photoluminescence architectures for disease diagnosis as well as theranostics. These architectures are built through the simple self-assembly of labeled biomolecular probes with the substrate material, leading to signal quenching. Upon the specific interaction of the architecture with a target biomarker, the signal can be spontaneously restored in a reversible manner. Meanwhile, by co-loading therapeutic agents and employing the inherent photo-thermal properties of the material substrates, a combined disease imaging and therapy (theranostics) can be achieved. This review highlights the latest advances in the construction and application of graphene and TMD/O based thin-layer material composites for single-target and multiplexed detection of a variety of biomarkers and theranostics. These versatile material architectures, owing to their ease in preparation, low cost and flexibility in functionalization, provide promising tools for both basic biochemical research and clinical applications.
Developments in photoluminescence architectures, constructed by simple supramolecular self-assembly between graphene and graphene-like thin-layer materials and labeled biomolecular probes, are summarized. These material composites show a diverse range of diagnostic as well as theranostic applications, providing a new generation of promising tools for the clinical use.
Inspired by nature's ability to capture and release biological entities when required, P. Jonkheijm and co-workers have developed a microfluidic platform for the adhesion and light-triggered release of pathogenic E. coli. On page 6187, they achieve this using supported lipid bilayers bearing a ternary complex of methylviologen, a supramolecular host (cucurbit[8]uril), and a photo-active azobenzene glycoconjugate. The platform has the potential to be used for intricate fundamental studies dealing with the spatio-temporal characteristics of celladhesion and also the development of novel reusable biosensors.
Janus particles can self-assemble around microfabricated gears in reproducible configurations with a high degree of spatial and orientational order. The final configuration maximizes the torque applied on the rotor leading to a unidirectional and steady rotating motion. The interplay between geometry and dynamical behavior leads to the self-assembly of Janus micromotors starting from randomly distributed particles.
A novel protein recognition platform is developed using aptamer-linked polythiophene nanowires. As the aptamer functionalized poly (3-methylthiophene) nanowire is treated by the specific protein, resonance Raman and photoluminescence signals are simultaneously enhanced. Statistical analyses deliver the capability of a single conjugated polymer nanowire with phase-transition characteristics in response to selectivity and concentration.
Conventional chemotherapy shows moderate efficiency against metastatic cancer since it targets only part of the mechanisms regulating tumor growth and metastasis. Here, gold nanorod (GNR)-based host-guest nanoplatforms loaded with docetaxel (DTX) and small interfering RNA (siRNA)-p65 (referred to as DTX-loaded GNR (GDTX)/p65) for chemo-, RNA interference (RNAi), and photothermal ablation (PTA) cooperative treatment of metastatic breast cancer are reported. To prepare the nanoplatform, GNRs are first coated with cyclodextrin (CD)-grafted polyethylenimine (PEI) and then loaded with DTX and siRNA through host–guest interaction with CD and electrostatic interaction with PEI, respectively. Upon near-infrared laser irradiation, GNRs generate a significant hyperthermia effect to trigger siRNA and DTX release. DTX reduces tumor growth by inhibiting mitosis of cancer cells. Meanwhile, siRNA-p65 suppresses lung metastasis and proliferation of cancer cells by blocking the nuclear factor kappa B (NF-κB) pathway and downregulating the downstream genes matrix metalloproteinase-9 (MMP-9) and B cell lymphoma-2 (Bcl-2). It is demonstrated that GDTX/p65 in combination with laser irradiation significantly inhibits the growth and lung metastasis of 4T1 breast tumors. The antitumor results suggest promising potential of the host–guest nanoplatform for combinational treatment of metastatic cancer by using RNAi, chemotherapy, and PTA.
Novel host–guest gold nanorods (GNRs) loaded with docetaxel (DTX) and small interfering RNA (siRNA), namely GDTX/siRNA, for cooperative treatment of metastatic cancer are demonstrated. Upon near infrared laser illumination, GNRs generate a tunable hyperthermia effect to trigger cytosol release of siRNA and DTX. GDTX/siRNA hybrid nanoparticles can suppress the invasiveness of cancer cells and sensitize the latter to DTX treatment by downregulating p65 expression.