G-quartet-based nanostructure for mimicking light-harvesting antenna

Novel aerogels based on supramolecular G-quadruplex assembly with intrinsic flame retardancy and thermal insulation

The construction of supramolecular aerogels still faces great challenges. Herein, we present a novel bio-based supramolecular aerogel derived from G-Quadruplex self-assembly of guanosine (G), boric acid (B) and sodium alginate (SA) and the obtained GBS aerogels exhibit superior flame-retardant and thermal insulating properties. The entire process involves environmentally friendly aqueous solvents and freeze-drying. Benefiting from the supramolecular self-assembly and interpenetrating dual network structures, GBS aerogels exhibit unique structures and sufficient self-supporting capabilities. The resulting GBS aerogels exhibit overall low densities (36.5-52.4 mg/cm3), and high porosities (>95 %). Moreover, GBS aerogels also illustrate excellent flame retardant and thermal insulating properties. With an oxygen index of 47.0-51.1 %, it can easily achieve a V-0 rating and low heat, smoke release during combustion. This work demonstrates the preparation of intrinsic flame-retardant aerogels derived from supramolecular self-assembly and dual cross-linking strategies, and is expected to provide an idea for the realization and application of novel supramolecular aerogel materials.

Machine-Learning-Driven G-Quartet-Based Circularly Polarized Luminescence Materials

Circularly polarized luminescence (CPL) materials have garnered significant interest due to their potential applications in chiral functional devices. Synthesizing CPL materials with a high dissymmetry factor (glum ) remains a significant challenge. Inspired by efficient machine learning (ML) applications in scientific research, this work demonstrates ML-based techniques for the first time to guide the synthesis of G-quartet-based CPL gels with high glum values and multiple chiral regulation strategies. Employing an "experiment-prediction-verification" approach, this work devises a ML classification and regression model for the solvothermal synthesis of G-quartet gels in deep eutectic solvents. This process illustrates the relationship between various synthesis parameters and the glum value. The decision tree algorithm demonstrates superior performance across six ML models, with model accuracy and determination coefficients amounting to 0.97 and 0.96, respectively. The screened CPL gels exhibiting a glum value up to 0.15 are obtained through combined ML guidance and experimental verification, among the highest ones reported till now for biomolecule-based CPL systems. These findings indicate that ML can streamline the rational design of chiral nanomaterials, thereby expediting their further development.

Alkaline earth cations binding mode tailors excited-state charge transfer properties of guanine quadruplex: A TDDFT study

Quadruplexes formed by nucleic acids and their derivates tend to chelate different monovalent and bivalent cations, which simultaneously affect their excited electronic states properties. Cation binding to every and every other cavity of the central ion channel could be exploited for tuning exited-state charge transfer properties. In this work we utilize set of descriptors constructed on the basis of the one-electron transition density matrix obtained using linear-response TDDFT to study excited states properties of four crystallized tetramolecular quadruplexes that chelate alkaline earth cations (Ca²⁺, Sr²⁺ and Ba²⁺). Here, we show that alkaline earth cations situated at adjacent vacancies promote existence of the nucleobase-metal charge separation (CS) states, contrary to the structures with cations that occupy every second available vacancy. We argued that stabilization of these CS states is due to the strong electric field that stabilizes d orbitals of the cations which accept an excited-electron. Moreover, CS content is increased and redshifted below the first bright transition when number of the chelated cations is increased. Hydration effects stabilized CS states and increased their relative content. We also identified electron detachment states in the broad energy range for the Ca²⁺ containing system. These findings are valuable for understanding and development of the novel nanostructures based on the quadruplex scaffold with adjustable optical properties.

Heterocycle-modified 2'-Deoxyguanosine Nucleolipid Analogs Stabilize Guanosine Gels and Self-assemble to Form Green Fluorescent Gels

Nucleoside-lipid conjugates are very useful supramolecular building blocks to construct self-assembled architectures suited for biomedical and material applications. Such nucleoside derivatives can be further synthetically manipulated to endow additional functionalities that could augment the assembling process and impart interesting properties. Here, we report the design, synthesis and self-assembling process of multifunctional supramolecular nucleolipid synthons containing an environment-sensitive fluorescent guanine. The amphiphilic synthons are composed of an 8-(2-(benzofuran-2-yl)vinyl)-guanine core and alkyl chains attached to 3'-O and 5'-O-positions of 2'-deoxyguanosine. The 2-(benzofuran-2-yl)vinyl (BFV) moiety attached at the C8 position of the nucleobase adopted a syn conformation about the glycosidic bond, which facilitated the self-assembly process through the formation of a G-tetrad as the basic unit. While 3',5'-diacylated BFV-modified dG analog stabilized the guanosine hydrogel by hampering the crystallization process and imparted fluorescence, BFV-modified dGs containing longer alkyl chains formed a green fluorescent organogel, which transformed into a yellow fluorescent gel in the presence of a complementary non-fluorescent cytidine nucleolipid. The ability of the dG analog containing short alkyl chains to modulate the mechanical property of a gel, and interesting fluorescence properties and self-assembling behavior exhibited by the dG analogs containing long alkyl chains in response to heat and complementary base underscore the potential use of these new supramolecular synthons in material applications.

Mimicking the Energy Funnel of the Photosynthetic Unit Using a Dendrimer-Dye Supramolecular Assembly

Photosynthesis involves light-harvesting complexes where an array of antenna pigment channels the absorbed solar energy to the reaction centre of a photosystem. This work reports a supramolecular dendrimer-dye assembly that mimics the natural light-harvesting mechanism. A dendrimeric molecule based on two-fluorophores has been constructed with three coumarin units at the end of three long arms and a 7-diethylaminocoumarin unit at the interior. The molecule self-aggregates in water into spherical micelles, which can encapsulate a rose-bengal dye (RB). On excitation, peripheral coumarin units shuttled the energy to the loaded RB dye reaction center via a two-step cascade resonance energy transfer (RET). The energy absorbed in the periphery is funnelled efficiently, resulting in a strong emission from the dye that resembles an energy funnel. The energy transfer cascade has been studied with both steady-state and time-resolved fluorescence spectroscopy. Molecular dynamics simulations of the self-assembled aggregates in water were also in agreement with the experimental observations.

Recomposition and storage of sunlight with intelligent phosphors for enhanced photosynthesis

This work presents a smart solar energy regulation strategy using photon tunable long persistent phosphors as solar energy harvesting antennas to enhance overall sunlight utilization by photosynthetic organisms in multiple modes.

Molecular Rotors as Guest Fluorophores Probing the Local Environment inside Host G4 Supramolecular Hydrogels

Fluorescent molecular rotors with a high binding affinity toward the guanosine quartet (G4) were incorporated as guest fluorophores into host supramolecular hydrogels based on the self-assembly of G4 units, to probe the local environment. Torsional dynamics of the rotors were severely inhibited inside the hydrogels in comparison with aqueous solutions, although the hydrogels were composed of >95% water. Moreover, even though all the gels were rigid bodies with no spontaneous deformation or flow property at room temperature, torsional dynamics in G4 borate gels was found to be consistently several orders of magnitude slower than those in the other G4 gels, irrespective of the identity of the molecular rotor probe. This clear difference in the molecular mobilities of the guest fluorophore could be attributed to systematic differences in the internal structure between the two categories of host G4 hydrogels. In specific terms, the borate groups in G4 borate hydrogels serve as bridging units between separate G4 quadruplex strands, generating additional cross-links that reinforce the network structure of the gel. The results demonstrate that molecular rotors act as efficient fluorescent probes for the quantitative assessment of the molecular-level environment and dynamics inside the hydrogels, an aspect that is missed out by most other analytical methods that are routinely employed for studying them.

Regulation of light-harvesting antenna based on silver ion-enhanced emission of dye-doped coordination polymer nanoparticles

The design and construction of artificial light-harvesting systems for solar energy conversion to chemical energy has been an active research field. A variety of molecules and materials have been used to mimic the function of the light-harvesting antenna. However, the improvement or regulation of the antenna effect of the existing artificial light-harvesting systems is less explored. Coordination polymers have aroused extensive concern due to their applications in light-harvesting and energy conversion. Herein, it is found that silver ion can dramatically enhance the emission of dye encapsulated in the coordination polymer nanoparticles (CPNs). The mechanism of Ag⁺-induced fluorescence enhancement is elucidated. Taking advantage of the effect of Ag⁺ ions, the regulation of CPN-based light-harvesting system by Ag⁺ is achieved for the first time. The antenna effect could be up to 2.3 times the original value by adding Ag⁺ ions. The present work provides a new approach to regulate the antenna effect of the light-harvesting system with the advantages of convenience, rapidity, low cost, and flexibility.

Ratiometric Fluorescent Mapping of pH and Glutathione Dictates Intracellular Transport Pathways of Micellar Nanoparticles

Visualization of intracellular transport pathways is crucial to investigate the internalization mechanism and understand the intracellular behavior of nanomaterials. Herein, we rationalized the design of micellar nanoparticles (NPs) for ratiometric fluorescent mapping of intracellular pH and glutathione (GSH), two essential parameters for maintaining normal cellular functions. Specifically, pH-sensitive naphthalimide-based probe (NPI) and pH-inert rhodamine B (RhB) were covalently labeled to double hydrophilic block copolymers (DHBCs) using the thiolactone chemistry, enabling the covalent attachment of NPI and RhB to one molecule with a redox-responsive disulfide linkage. The dually labeled DHBCs exhibited blue/orange dual emissions in acidic pH, which was further converted into green/orange dual emissions in neutral pH because of the deprotonation of NPI moieties and the sole green emission in the presence of GSH at neutral pH because of the decreased Förster resonance energy transfer efficiency between an NPI donor and an RhB acceptor as a result of GSH-mediated cleavage of disulfide bonds. These remarkable ratiometric fluorescence changes allowed for not only the simultaneous mapping of the intracellular pH and GSH but also the intracellular transport pathways of internalized NPs.

Right-/left-handed helical G-quartet nanostructures with full-color and energy transfer circularly polarized luminescence

Right (R)- and left (L)-handed helical G-quartet nanostructures were synthesized for the first time simultaneously via the self-assembly of 5'-guanosine monophosphate (GMP), the helical handedness of which is well regulated by metal ions. These g-nanostructures were further applied as circularly polarized luminescence (CPL) templates to realize full-color R-/L-CPL and Förster resonance energy transfer CPL. The glum value reached 10-2, indicating their excellent template function for CPL materials design and application.

A new approach to construct and modulate G-quadruplex by cationic surfactant

HYPOTHESIS

G-quadruplex structure has raised increasing attention in supramolecular chemistry as an effective template for ordered functional materials. Thus, it is of practical significance to advance our understanding regarding G-quadruplex structures. Typically, G-quadruplex structures are formed in the presence of suitable metal ions. New methods to construct such structures need to be explored.

EXPERIMENTS

The supramolecular assembly between CTAB and a guanosine derivative at different molar ratios was systematically studied, including assembly mechanisms, morphology, and macroscopic properties. Cationic surfactants with different alkyl chains were studied as control experiments.

FINDINGS

A novel strategy to construct G-quadruplex with the promotion of the cationic surfactant CTAB is presented in this work. The structure-property relationships of G-quadruplex gels are characterized by rheology and shrinkage ratio experiments. MacKintosh's theory was used to rationalize the relationship between gel elasticity and water content. The transition of G-quadruplex structures could be easily enabled by modulating CTAB concentration, which promotes the phase transition from gel/sol biphase to homogeneous sol phase. This work will provide a new viewpoint for the construction and modulation of G-quadruplex structures.

Fabricating a fluorescence resonance energy transfer system with AIE molecular for sensitive detection of Cu(II) ions

The aggregation-induced emission (AIE) luminogens has exhibited strong potential in fabricating the fluorescence resonance energy transfer (FRET) system. In this paper one efficient FRET system was fabricated in aqueous solution based on an AIE molecular (T) and Nile Red (NiR) dyes: T acts as the energy donor and NiR acts as the energy acceptor with a ratio of 250:1. The energy-transfer efficiency from the donor to acceptor is 82.52%, and the antenna effect is 24.9. Base on this data, a very low detection limit for Cu²⁺ was calculated to be 35.5 pM. This method displays penitential application on fluorescence probe for small ions or molecular detection by light-harvesting system based on a simple AIE donor under physiological conditions.

Studying the excited electronic states of guanine rich DNA quadruplexes by quantum mechanical methods: main achievements and perspectives

Calculations are providing more and more useful insights into the interaction between light and DNA quadruplexes.

Photoswitchable Fluorescent Crystals Obtained by the Photoreversible Coassembly of a Nucleobase and an Azobenzene Intercalator

Self-assembled nucleobases, such as G-quartets or quadruplexes, have numerous applications, but light-responsive structures are limited to small, noncrystalline motifs. In addition, the assembly of the widely exploited azobenzene photochromic compounds can produce fluorescent crystals of extended dimensions but at the prize of sacrificing their photoswitchability. Here, we overcome inherent limitations of self-assembly with a new concept of supramolecular coassembly leading to materials with unprecedented properties. We show that the coassembly of guanosine monophosphate (GMP) with an azobenzene-containing DNA intercalator produces supramolecular crystals arranged through a combination of π-π, electrostatic, and hydrogen-bond interactions. The resulting crystals are 100 μm long, pH-sensitive, fluorescent, and can be photoreversibly disassembled/reassembled upon UV/blue irradiation. This allows us to perform operations such as dynamic photocontrol of a single-crystal growth, light-gated permeability in membrane-like materials, and photoswitchable fluorescence. We believe this concept critically expands the breadth of multifunctional materials attainable by self-assembly.

G-Quadruplex based hydrogels stabilized by a cationic polymer as an efficient adsorbent of picric acid

Hydrogels based on G-quadruplexes (G-hydrogels) were prepared using guanosine 5′-monophosphate disodium salt, GMP, with a hyperbranched poly(ethylenimine), PEI, containing abundant –NH₂ groups.

Understanding complex supramolecular landscapes: non-covalent macrocyclization equilibria examined by fluorescence resonance energy transfer

As molecular self-assembled systems increase in complexity, due to a large number of participating entities and/or the establishment of multiple competing equilibria, their full understanding becomes likewise more complicated, and the use of diverse analytical techniques that can afford complementary information is required. We demonstrate in this work that resonance excitation energy transfer phenomena, measured by fluorescence spectroscopy in combination with other optical spectroscopies, can be a valuable tool to obtain supplementary thermodynamic data about complex supramolecular landscapes that other methods fail to provide. In particular, noncovalent macrocyclization processes of lipophilic dinucleosides are studied here by setting up a competition between intra- and intermolecular association processes of Watson-Crick H-bonding pairs. Multiwavelength analysis of the monomer emission changes allowed us to determine cyclotetramerization constants and to quantify chelate cooperativity, which was confirmed to be substantially larger for the G-C than for the A-U pair. Furthermore, when bithiophene-BODIPY donor-acceptor energy transfer probes are employed in these competition experiments, fluorescence and circular dichroism spectroscopy measurements in different regions of the visible spectrum additionally reveal intermolecular interactions occurring simultaneously at both sides of the macrocyclization reaction: the cyclic product, acting as a host for the competitor, and the monomer reactant, ultimately leading to macrocycle denaturation.

Allosteric Self-Assembly of Coordinating Terthiophene Amphiphile for Triggered Light Harvesting

Allosteric regulation is extensively employed by nature to achieve functional control of protein or deoxyribonucleic acid through triggered conformational change at a remote site. We report that a similar strategy can be utilized in artificial self-assembly to control the self-assembled structure and its function. We show that on binding of metal ions to the headgroup of an amphiphile TTC4L, the conformational change may lead to change of the dipole orientation of the energy donor at the chain end. This on the one hand leads to a drastically different self-assembled structure; on the other hand, it enables light harvesting between the donor-acceptor. Because the Forster resonance fluorescence transfer efficiency is gated by metal ions, controlling the feeding of metal ions allows switching on and off of light harvesting. We expect that using allosteric self-assembly, we will be able to create abundant structures with distinct function from limited molecules, which show prominent potential for the postorganic modification of the structure and function of self-assembled materials.

Nucleotide-Based Assemblies for Green Synthesis of Silver Nanoparticles with Controlled Localized Surface Plasmon Resonances and Their Applications

The sizes, shapes, and surface characteristics of nanomaterials determine their unique physical, chemical, and biological properties. Localized surface plasmon resonance (LSPR) is one of the unique optical properties of noble-metal nanoparticles. The synthesis of nanomaterials using biomolecules as templates offers an excellent strategy to control and regulate their features. Herein, for the first time, we demonstrate a green synthesis approach of silver nanoparticles (AgNPs) using nucleotide-based assemblies as templates. Moreover, we investigate the influence of different nucleotide-based assemblies and metal ions on the preparation of AgNPs, implying that AgNPs with different LSPR absorptions originating from their surrounding and size could be synthesized. The synthetic route is green, energy-effective, and feasible. On the basis of the unique LSPR-controlled property, the AgNP composites were applied for cryptography, biothiol detection, and designing logic gates. This work offers a promising method for the synthesis of nanomaterials with multiapplications.

Artificial light-harvesting supramolecular polymeric nanoparticles formed by pillar[5]arene-based host-guest interaction

Artificial light-harvesting nanoparticles were prepared from supramolecular polymers comprised of pillar[5]arene with anthracene-derived donors and acceptors through host-guest interactions. The resulting water-dispersible nanoparticles displayed efficient energy transfer and excellent light harvesting ability in part because the steric bulk of pillar[5]arene suppressed the self-quenching of the chromophores.

A self-assembled peroxidase from 5'-GMP and heme

Guanosine 5'-monophosphate (5'-GMP) and Fe(iii)-heme form a supramolecular catalyst with peroxidase activity. Catalysis, which depends on self-assembly of 5'-GMP into a G-quadruplex that binds hemin, can be modulated by nucleotide concentration, temperature and the identity of the nucleotide's sugar.

Nucleobases, nucleosides, and nucleotides: versatile biomolecules for generating functional nanomaterials

The incorporation of biomolecules into nanomaterials generates functional nanosystems with novel and advanced properties, presenting great potential for applications in various fields. Nucleobases, nucleosides and nucleotides, as building blocks of nucleic acids and biological coenzymes, constitute necessary components of the foundation of life. In recent years, as versatile biomolecules for the construction or regulation of functional nanomaterials, they have stimulated interest in researchers, due to their unique properties such as structural diversity, multiplex binding sites, self-assembly ability, stability, biocompatibility, and chirality. In this review, strategies for the synthesis of nanomaterials and the regulation of their morphologies and functions using nucleobases, nucleosides, and nucleotides as building blocks, templates or modulators are summarized alongside selected applications. The diverse applications range from sensing, bioimaging, and drug delivery to mimicking light-harvesting antenna, the construction of logic gates, and beyond. Furthermore, some perspectives and challenges in this emerging field are proposed. This review is directed toward the broader scientific community interested in biomolecule-based functional nanomaterials.

Structure-Property Relationships in CuII -Binding Tetramolecular G-Quadruplex DNA

A series of artificial metal-base tetrads composed of a Cu^II cation coordinating to four pyridines, covalently attached to the ends of tetramolecular G-quadruplex DNA strands [L^A-D d(G₄ )]₄ (L^A-D =ligand derivatives), was systematically studied. Structurally, the square-planar [Cu(pyridine)₄ ] complex behaves analogously to the canonical guanine quartet. Copper coordination to all studied ligand derivatives was found to increase G-quadruplex thermodynamic stability, tolerating a great variety of ligand linker lengths (1-5 atoms) and thus demonstrating the robustness of the chosen ligand design. Only at long linker lengths, the stabilizing effect of copper binding is compensated by the loss of conformational freedom. A previously reported ligand L^E with chiral backbone enables incorporation at any oligonucleotide position. We show that ligand chirality distinctly steers Cu^II -induced G-quadruplex stabilization. 5'-End formation of two metal-base tetrads by tetramolecular G-quadruplex [L^E₂ d(G)₄ ]₄ shows that stabilization in the presence of Cu^II is not additive. All results are based on UV/Vis thermal denaturation, thermal difference, circular dichroism experiments and molecular dynamics simulations.

Coordination polymer nanoparticles from nucleotide and lanthanide ions as a versatile platform for color-tunable luminescence and integrating Boolean logic operations

Novel supramolecular coordination polymer nanoparticles (CPNs) were synthesized via the self-assembly of guanosine monophosphate (GMP) and lanthanide ions (Ln³⁺, including Tb³⁺, Eu³⁺ and Ce³⁺) in aqueous solution. These CPNs (GMP/Tb³⁺, GMP/Eu³⁺ and GMP/Ce³⁺) have an identical coordination environment but exhibit completely different luminescence properties responding to external stimuli such as dipicolinic acid (DPA), ethylene diamine tetraacetic acid (EDTA), pH and metal ions, which has inspired us to tune the emission color of the CPNs and perform multiple logic operations. Firstly, color-tunable luminescence from red to green can be easily achieved by modulating the doping ratio of Tb³⁺ and Eu³⁺ into GMP. Notably, trichromatic white light emitting CPNs can be successfully realized by simultaneously doping Tb³⁺, Eu³⁺ and Ce³⁺ into the host or just adjusting the pH of the solution. What's more, by employing GMP/Tb³⁺ CPNs as a logic operator, we have achieved the implementation of multilayered gate cascades (INH-INH, NOR-OR). When GMP/Eu³⁺ CPNs served as a logic operator, the logic elements can be integrated as another combinatorial gate (AND-INH). Moreover, by employing the red emission of Eu³⁺ and blue emission of GMP as the dual-output signal transducer, a set of parallel logic gates was established successfully. These results help elucidate the design rules by which simple logic can be integrated to construct cascaded logic gates and expand the applications of CPNs in light-emitting diode (LED) lamps and biological systems.

Dye-conjugated complementary lipophilic nucleosides as useful probes to study association processes by fluorescence resonance energy transfer

Resonance energy transfer is used here to study the association and self-sorting events between lipophilic nucleosides in apolar aromatic solvents.

FRET efficiency and antenna effect in multi-color DNA origami-based light harvesting systems

Artificial light harvesting complexes find applications in photosynthesis, photovoltaics and chemical sensors. Here, we present the characterization and optimization of a multi-color artificial light harvesting system on DNA origami structures.

Light-Harvesting Antennae Based on Silicon Nanocrystals

Silicon (Si) nanocrystals are relatively strong light emitters, but are weak light absorbers as a result of their indirect band gap. One way to enhance light absorption is to functionalize the nanocrystals with chromophores that are strong light absorbers. By designing systems that enable efficient energy transfer from the chromophore to the Si nanocrystal, the brightness of the nanocrystals can be significantly increased. There have now been a few experimental systems in which covalent attachment of chromophores, efficient energy transfer and significantly increased brightness have been demonstrated. This review discusses progress on these systems and the remaining challenges.

Light-harvesting antennae based on photoactive silicon nanocrystals functionalized with porphyrin chromophores

Silicon nanocrystals functionalized with tetraphenylporphyrin Zn(II) chromophores at the periphery perform as light harvesting antennae: excitation of the porphyrin units in the visible spectral region yields sensitized emission of the silicon nanocrystal core in the near infrared with a long lifetime (λ(max) = 905 nm, τ = 130 μs). This result demonstrates that this hybrid material has a potential application as a luminescent probe for bioimaging.

Transcription of G-quartet supramolecular aggregates into hierarchical mesoporous silica nanotubes

Hierarchical porous silica nanotubes or porous silica hollow spheres were prepared employing a low concentration of G-quartet supramolecular aggregates as a template.

Molecularly Defined Nanostructures Based on a Novel AAA-DDD Triple Hydrogen-Bonding Motif

A facile and flexible method for the synthesis of a new AAA-DDD triple hydrogen-bonding motif is described. Polytopic supramolecular building blocks with precisely oriented AAA and DDD groups are thus accessible in few steps. These building blocks were used for the assembly of large macrocycles featuring four AAA-DDD interactions and a macrobicyclic complex with a total of six AAA-DDD interactions.

DNA-Based Oligochromophores as Light-Harvesting Systems

The chromophores ethynyl pyrene as blue, ethynyl perylene as green and ethynyl Nile red as red emitter were conjugated to the 5-position of 2'-deoxyuridine via an acetylene bridge. Using phosphoramidite chemistry on solid phase labelled DNA duplexes were prepared that bear single chromophore modifications, and binary and ternary combinations of these chromophore modifications. The steady-state and time-resolved fluorescence spectra of all three chromophores were studied in these modified DNA duplexes. An energy-transfer cascade occurs from ethynyl pyrene over ethynyl perylene to ethynyl Nile red and subsequently an electron-transfer cascade in the opposite direction (from ethynyl Nile red to ethynyl perylene or ethynyl pyrene, but not from ethynyl perylene to ethynyl pyrene). The electron-transfer processes finally provide charge separation. The efficiencies by these energy and electron-transfer processes can be tuned by the distances between the chromophores and the sequences. Most importantly, excitation at any wavelength between 350 and 700 nm finally leads to charge separated states which make these DNA samples promising candidates for light-harvesting systems.

Targeting G-quadruplex structures with extrinsic fluorogenic dyes: promising fluorescence sensors

This article provides a brief account of the recent reports on the fluorescence properties of some of the fluorogenic dyes towards G-quadruplex DNAs, which have been turned into promising bio-analytical methods.