A DNA/metal cluster-based nano-lantern as an intelligent theranostic device

We constructed a DNA/metal cluster-based nano-lantern as a multifunctional theranostic system by combining various properties into one ingenious DNA device.

DNA metallization: principles, methods, structures, and applications

This review summarizes the research activities on DNA metallization since the concept was first proposed in 1998, covering the principles, methods, structures, and applications.

The fluorescence quenching and aggregation induced emission behaviour of silver nanoclusters labelled on poly(acrylic acid-co-maleic acid)

The P(AA-co-MA) AgNCs reveals fluorescence quenching and enhancement in the presence of GSH and DMSO, respectively.

DNA-templated silver nanoclusters: structural correlation and fluorescence modulation

12 years after the introduction of DNA-templated silver nanoclusters (DNA-AgNCs), exciting progress has been made and yet we are still in the midst of trying to fully understand this nanomaterial. The prominent excellence of DNA-AgNCs is undoubtedly its modulatable emission property, of which how variation in DNA templates causes emission tuning remains elusive. Based on the up-to-date DNA-AgNCs, we aim to establish the correlation between the structure/sequence of DNA templates and emission behaviour of AgNCs. Herein, we systematically present a wide-range of DNA-AgNCs based on the structural complexity of the DNA templates, including single-stranded DNA (ssDNA), double-stranded DNA (dsDNA), triple-stranded DNA (tsDNA) and DNA nanostructures. For each DNA category, we discuss the emission property, quantum yield and synthesis condition of the respective AgNCs, before cross-comparing the impact of different DNA scaffolds on the properties of AgNCs. A future outlook for this area is given as a conclusion. By putting the information together, this review may shed new light on understanding DNA-AgNCs while we are expecting continuous breakthroughs in this field.

Metal nanoclusters: novel probes for diagnostic and therapeutic applications

Metal nanoclusters, composed of several to a few hundred metal atoms, have received worldwide attention due to their extraordinary physical and chemical characteristics. Recently, great efforts have been devoted to the exploration of the potential diagnostic and therapeutic applications of metal nanoclusters. Here we focus on the recent advances and new horizons in this area, and introduce the rising progress on the use of metal nanoclusters for biological analysis, biological imaging, therapeutic applications, DNA assembly and logic gate construction, enzyme mimic catalysis, as well as thermometers and pH meters. Furthermore, the future challenges in the construction of biofunctional metal nanoclusters for diagnostic and therapeutic applications are also discussed. We expect that the rapidly growing interest in metal nanocluster-based theranostic applications will certainly not only fuel the excitement and stimulate research in this highly active field, but also inspire broader concerns across various disciplines.

A dual input DNA-based molecular switch

We have designed and characterized a DNA-based molecular switch which processes two physiologically relevant inputs: pH (i.e. alkalinisation) and enzymatic activity, and generates a chemical output (in situ synthesized oligonucleotide). The design, based on allosteric interactions between i-motif and hairpin stem within the DNA molecule, addresses such critical physiological system parameters as molecular simplicity, tunability, orthogonality of the two input sensing domains, and compatibility with intracellular operation/delivery.

Spectroscopic study on the formation of DNA-Ag clusters and its application in temperature sensitive vehicles of DOX

DNA silver nanoclusters (DNA-AgNCs) with a fluorescence emission at 610 nm were synthesized using a special hairpin DNA sequence (5'-AGCACGTAG-C3AC3AC3GC3A-CTACGTGCT-3'). Spectroscopic data demonstrate that the DNA changed from an i-motif structure containing C-quadruplexes to anti-parallel four strands structure during the formation of DNA-AgNCs. Importantly, the loose and compact four strand structure caused by the melting and hybridization of stem duplex was confirmed by the reversible fluorescence change of DNA-AgNCs in the range of 25-66°C. Herein, DNA-AgNCs were used as temperature sensitive vehicles of drug loading. The drug loading capacity is 1 Doxorubicin (Dox) molecules per CG pairs on stem-duplexes. The loaded Dox can be released by raising temperature with the melt of stem duplex. Moreover, the special DNA sequence makes it sensitive to the HepG-2 cells.

Fluorescence modulation of a pyrazolone dye in the solid state based on energy transfer

A photochromic pyrazolone is exploited as a modulator to toggle the fluorescence of a dye “on” and “off” based on energy transfer.

Nucleic acids and smart materials: advanced building blocks for logic systems

Logic gates can convert input signals into a defined output signal, which is the fundamental basis of computing. Inspired by molecular switching from one state to another under an external stimulus, molecular logic gates are explored extensively and recognized as an alternative to traditional silicon-based computing. Among various building blocks of molecular logic gates, nucleic acid attracts special attention owing to its specific recognition abilities and structural features. Functional materials with unique physical and chemical properties offer significant advantages and are used in many fields. The integration of nucleic acids and functional materials is expected to bring about several new phenomena. In this Progress Report, recent progress in the construction of logic gates by combining the properties of a range of smart materials with nucleic acids is introduced. According to the structural characteristics and composition, functional materials are categorized into three classes: polymers, noble-metal nanomaterials, and inorganic nanomaterials. Furthermore, the unsolved problems and future challenges in the construction of logic gates are discussed. It is hoped that broader interests in introducing new smart materials into the field are inspired and tangible applications for these constructs are found.

Individual inorganic nanoparticles: preparation, functionalization and in vitro biomedical diagnostic applications

Inorganic nanoparticles have become the focus of modern materials science due to their potential technological importance, particularly in bionanotechnology, which stems from their unique physical properties including size-dependent optical, magnetic, electronic, and catalytic properties. The present article provides an overview on the currently used individual inorganic nanoparticles for in vitro biomedical domains. These inorganic nanoparticles include iron oxides, gold, silver, silica, quantum dots (QDs) and second harmonic generation (SHG) particles. For each of these interesting nanoparticles, the main issues starting from preparation up to bio-related applications are presented.