Luminescent Ag6Au6 heterometallic ethisterone cluster and probe for estrogen receptor α.

A heterometallic cluster [Ag6Au6(ethisterone)12] of an unprecedented topology was synthesized and characterized. A sensitive and specific probe for estrogen receptor α (ERα) has been developed for the first time based on the enhancement of the Ag6Au6 luminescence.

Ultrasensitive colorimetric carcinoembryonic antigen biosensor based on hyperbranched rolling circle amplification.

In this study, a hyperbranched rolling circle amplification (HRCA)-based colorimetric biosensor for carcinoembryonic antigen (CEA) is developed with high sensitivity and specificity. A CEA aptamer can bind with its target (CEA) to form a complex due to their high affinity, and the introduced CDNA cannot hybridize with the aptamer. Thus, free CDNA can propagate the HRCA reaction to form a large number of single-stranded DNA (ss-DNA).

Pt2Ag acetylide-doped silica nanoparticles: enabling luminescence of Pt2Ag complexes in water and sensors for highly sensitive detection of cyanide anions.

Two novel luminescent hetero-trinuclear complexes [Pt2Ag(μ-dpppy)2(C≡CC6H4R-4)4](ClO4) (R = H, 1; R = CH3, 2; dpppy = 2,6-bis(diphenylphosphino)pyridine) were synthesized by the self-assembly reaction between [Pt(C[triple bond, length as m-dash]CC6H4R-4)4](2-) and [Ag2(μ-dpppy)3](2+) and characterized by elemental analyses, electrospray ionization mass spectrometry, and (1)H NMR and (31)P{(1)H} NMR spectroscopy and by X-ray crystallography for complex 2. Two Pt2Ag complexes show strong luminescence in the solid state, but exhibit weak emission in CH2Cl2 solution and in acetonitrile-water (1 : 1, v : v) solution at room temperature. To overcome the limitations of low water solubility and weak emission in solutions, a new kind of luminescent Pt2Ag@SiO2 nanoparticles was prepared by incorporating the new Pt2Ag acetylides into monodisperse silica nanoparticles.

Graphitic-phase CN nanosheets as efficient photosensitizers and pH-responsive drug nanocarriers for cancer imaging and therapy.

Graphitic-phase carbon nitride (g-CN) nanosheets, the newly emerging two-dimensional (2D) layered nanomaterials, have been demonstrated to be promising bioimaging agents due to their high photoluminescence (PL) quantum yields, good biocompatibility and low toxicity. However, the therapeutic applications of g-CN nanosheets have not been explored until now. In this study, we have proven for the first time that g-CN nanosheets can be used as efficient photosensitizers for photodynamic tumor therapy and as pH-responsive nanocarriers for drug delivery.

Synthesis, characterization, DNA binding, cleavage activity and cytotoxicity of copper(II) complexes.

Three new mononuclear copper(II) complexes, [Cu(L2)](2+) (1), [Cu(acac)(L)](+) (2), and [Cu(acac-Cl)(L)](+) (3) (L = 2-(4-pyridine)oxazo[4,5-f]1,10-phenanthroline (4-PDOP); acac = acetylacetone; acac-Cl = 3-chloroacetylacetone), have been synthesized and characterized by elemental analysis, high resolution mass spectrometry (Q-TOF), and IR spectroscopy. Two of the complexes were structurally characterized by single-crystal X-ray diffraction techniques. Their interactions with DNA were studied by UV-vis absorption and emission spectra, viscosity, thermal melting, DNA unwinding assay and CD spectroscopy.

Dye-enhanced graphene oxide for photothermal therapy and photoacoustic imaging.

Graphene oxide (GO) has many exciting advantages such as easy preparation, low toxicity, good solubility and stability in aqueous solution. However, GO itself has a low near-infrared (NIR) absorption, and thus is not suitable for photothermal therapy and photoacoustic imaging. To overcome this limitation, a novel dye-enhanced GO is prepared utilizing the π-π stacking interactions between GO and indocyanine green (ICG).

Synthesis, characterization, and DNA binding of a novel ligand and its Cu (II) complex.

A novel naphthalene-2,3-diamine-2-salicylaldehyde (NS) ligand and its mononuclear copper(II) complex (CuNS) have been synthesized and structurally characterized. The UV–vis absorption and emission spectra of NS showed obvious changes on addition of Cu2+ solution. The interaction of the compounds with calf thymus DNA and G-quadruplex DNA were investigated by spectroscopic methods and thermal melting assay.

A selective artificial enzyme inhibitor based on nanoparticle-enzyme interactions and molecular imprinting.

A novel and general strategy is developed to design selective artificial enzyme inhibitor based on nanoparticleenzyme inter actions and molecular imprinting. Due to the creation of specific binding cavities, the resulting artificial inhibitor has high inhibition efficiency for the target enzyme, and shows great target-selectivity over other enzymes of similar function and proteins of compaable mole cular weight.

Ultrasensitive electrochemical detection of cancer-associated circulating microRNA in serum samples based on DNA concatamers.

MicroRNAs (miRNAs), a kind of endogenous, noncoding RNAs (19-24 nucleotides), play vital roles in regulating gene expression and cellular processes. In recent years, it has been found that circulating miRNAs are differentially expressed in patients and healthy controls. This leads to the suggestion that circulating miRNAs are promising biomarkers for cancer classification and prognosis.

Highly-efficient peroxidase-like catalytic activity of graphene dots for biosensing.

In recent years, considerable efforts have been devoted to the construction of efficient enzyme mimetics, which have significant advantages of simple synthesis, good stability and design flexibility. In this paper, we described that graphene dots (GDs) possess highly-efficient peroxidase-like catalytic activity, and its activity is much higher than graphene oxide (GO) with large size. They can catalyze the oxidation of peroxidase substrate 3,3,5,5-tetramethylbenzidine (TMB) in the presence of H2O2 to produce a blue product, which can be used for H2O2 detection by measuring the absorbance change.

Topological insulator bismuth selenide as a theranostic platform for simultaneous cancer imaging and therapy.

Employing theranostic nanoparticles, which combine both therapeutic and diagnostic capabilities in one dose, has promise to propel the biomedical field toward personalized medicine. Here we investigate the theranostic properties of topological insulator bismuth selenide (Bi2Se3) in in vivo and in vitro system for the first time. We show that Bi2Se3 nanoplates can absorb near-infrared (NIR) laser light and effectively convert laser energy into heat.

Targeted photothermal ablation of pathogenic bacterium, Staphylococcus aureus, with nanoscale reduced graphene oxide.

Nowadays, bacterial infection is very common in the world. As a result of overusing antibiotics, several human pathogenic bacteria have become resistant to most of the clinically approved antibiotics. This has created an urgent need for the development of new methods to kill pathogenic bacteria.

Study on the electrochemical catalytic properties of the topological insulator Bi₂Se₃.

In this work, the electrochemical catalytic properties of the topological insulator bismuth selenide (Bi₂Se₃) were first studied. In the presence of Bi₂Se₃ the reduction current of dissolved O₂ could be significantly enhanced. The electron transfer resistivity (Rct) was greatly reduced at the Bi₂Se₃-PVP modified electrode as evidenced by the electrochemical impedance spectrometry, implying that the topological insulator Bi₂Se₃ could facilitate the electron transfer at the interface due to the excellent surface conductivity.

Glutathione-functionalized graphene quantum dots as selective fluorescent probes for phosphate-containing metabolites.

Bright blue fluorescent glutathione-functionalized graphene quantum dots (GQDs@GSH) were prepared by a one-step pyrolysis method with a fluorescence quantum yield as high as 33.6%. Futhermore, the obtained GQDs@GSH can be used as a probe to estimate the ATP level in cell lysates and human blood serum.

Simple colorimetric bacterial detection and high-throughput drug screening based on a graphene-enzyme complex.

A simple, colorimetric, sensitive, cost-effective and high-throughput system based on a positively charged graphene oxide-enzyme complex was developed for bacterial detection and drug screening.

The early diagnosis and fast detection of blast fungus, Magnaporthe grisea, in rice plant by using its chitinase as biochemical marker and a rice cDNA encoding mannose-binding lectin as recognition probe.

As one of the most destructive and widespread disease of rice, Magnaporthe grisea (M. grisea) has a significant negative impact on rice production. Therefore, it is significant to develop a method for sensitive and high-throughput detection of M.

Label-free and fluorescence turn-on aptasensor for protein detection via target-induced silver nanoclusters formation.

A simple turn-on and homogeneous aptasensor, which relies on target induced formation of silver nanoclusters (Ag NCs), was developed for the determination of platelet-derived growth factor B-chain homodimer (PDGF-BB). The aptasensor contains two hairpin DNA probes termed as P1 and P2. P1 consists of the aptamer sequence of PDGF-BB.

Electrochemiluminescence properties of [Pt2Ag4(C≡CC6H4R)8]n (R = CH3, n = 1; R = H, n = 1 and 2) with amine (TPrA and DBAE) as the coreactant and determination of Sudan I.

Two hexanuclear clusters, [Pt(2)Ag(4)(C≡CC(6)H(4)R)(8)] (R = CH(3), 1; R = H, 2), together with dimer [Pt(2)Ag(4)(C≡CC(6)H(5))(8)](2) (3), have been synthesized and characterized by elemental analyses, electrospray ionization mass spectrometry, and (1)H NMR spectroscopy and by X-ray crystallography for 1 and 3. A considerable enhancement of photoluminescence (PL) and a notable red shift in the emission maximum of 1 (λ(max) 600 nm) relative to 2 (λ(max) 545 nm) are observed. Electrogenerated chemiluminescence (ECL) of 1 and 2 in the absence or presence of coreactant tri-n-propylamine (TPrA) or 2-(dibutylamino)ethanol (DBAE) at different working electrodes in different solvents (CH(2)Cl(2), CH(2)ClCH(2)Cl, or CH(3)CN) has been studied.

A novel fluorescent biosensor for detection of target DNA fragment from the transgene cauliflower mosaic virus 35S promoter.

In this paper, we reported a convenient fluorescence method for the detection of genetically modified organisms (GMOs). As it is known that the cauliflower mosaic virus (CaMV) 35S promoter is widely used in most transgenic plants (Schnurr and Guerra, 2000), we thus design a simple method based on the detection of a section target DNA (DNA-T) from the transgene CaMV 35S promoter. In this method, the full-length guanine-rich single-strand sequences were split into fragments (Probe 1 and 2) and each part of the fragment possesses two GGG repeats.

Ru(II) sensitized lanthanide luminescence: synthesis, photophysical properties, and near-infrared luminescent determination of alpha-fetal protein (AFP).

A series of dinuclear compounds of [Ru(bpy)(2)(tpphz)Ln(TTA)(3)](PF(6))(2) (tpphz = tetrapyrido[3,2-a:2',3'-c:3'',2''-h:3''',4'''-j]phenazine; Ln = Er(III), Nd(III), Yb(III) and Gd(III); TTA = 2-thenoyltrifluoroacetone) have been prepared by attachment of a [Ln(TTA)(3)] fragment at the vacant diimine site of the luminescent mononuclear complex [Ru(bpy)(2)(tpphz)](PF(6))(2). In the solid state, in CH(2)Cl(2) solution and in Tris-HCl buffer solution of these dinuclear complexes Ru-Ln, sensitized near-infrared (NIR) luminescence is observed from Nd and Yb centres following excitation of the d-block unit, which results from the effective Ru → Ln (Ln = Nd, Yb) energy transfer, but no Er-based NIR luminescence is produced. The (3)MLCT (MLCT = metal to ligand charge transfer) emission is partly quenched in the Ru-Nd complex, slightly increased in the Ru-Yb complex, and is not changed in the Ru-Ercomplex.

Synthesis, structure, photophysics and electrochemiluminescence of Re(I) tricarbonyl complexes with cationic 2,2-bipyridyl ligands.

Two water soluble Re(I) tricarbonyl diimine complexes containing cationic 2,2'-bipyridyl ligands [Re(L1)(CO)(3)(AN)](2+) (1) and [Re(L2)(CO)(3)(AN)](3+) (2) (L1 and L2: a cationic 2,2'-bipyridyl ligand, AN: acetonitrile) were synthesized and characterized. Their photophysical, electrochemical and electrochemiluminescent properties were investigated. The crystal structures of the two complexes have also been determined.

General colorimetric detection of proteins and small molecules based on cyclic enzymatic signal amplification and hairpin aptamer probe.

In this work, we developed a simple and general method for highly sensitive detection of proteins and small molecules based on cyclic enzymatic signal amplification (CESA) and hairpin aptamer probe. Our detection system consists of a hairpin aptamer probe, a linker DNA, two sets of DNA-modified AuNPs, and nicking endonuclease (NEase). In the absence of a target, the hairpin aptamer probe and linker DNA can stably coexist in solution.

A graphene oxide (GO)-based molecular beacon for DNA-binding transcription factor detection.

A GO-based molecular beacon assay was developed for rapid, sensitive and cost-efficient detection of transcription factor proteins. Furthermore, this assay can be employed for screening inhibitors of transcription factor proteins.

Efficient detection of secondary structure folded nucleic acids related to Alzheimer's disease based on junction probes.

Single stranded DNA often forms stable secondary structures under physiological conditions. These DNA secondary structures play important physiological roles. However, the analysis of such secondary structure folded DNA is often complicated because of its high thermodynamic stability and slow hybridization kinetics.