Core-shell gold nanocubes for point mutation detection based on plasmon-enhanced fluorescence.

Point mutation, with a permanent change in nucleic acid sequences, can affect the expression of genetic information forming the basis for numerous human genetic diseases, which makes its detection crucially important. Here, we reported a simple and sensitive method for point mutation detection, which employs a core-shell gold nanocube (Au NC) based on plasmon-enhanced fluorescence (PEF). For the generation of PEF, a Au NC was chosen as a core and silica as a spacer layer to adjust the distance between the Au NC and the dye of 5-carboxyfluorescein.

A comparative study of plasmonic-enhanced single-molecule fluorescence induced by gold nanoantennas and its application for illuminating telomerase.

A comparative study of plasmonic-enhanced single-molecule fluorescence (PESMF) induced by four gold nanoantennas is reported. The gold triangular nanoplate (Au TNP) is the optimal PESMF substrate for Cy5.5 owing to its sharpest point and strongest electric fields.

Silica-coated triangular gold nanoprisms as distance-dependent plasmon-enhanced fluorescence-based probes for biochemical applications.

Plasmon-enhanced fluorescence (PEF)-based anisotropic nanostructures are considered extremely promising tools for improving the inherent problems of traditional fluorophores and for detecting important biomolecules with high sensitivity. Herein, a novel triangular gold nanoprism (AuNPR)-based fluorescence probe, AuNPR@SiO@12,17-tetramethyl-3-dihydro-(2s-trans)-thyl-7(Ce6), was developed for PEF by virtue of multiple "hot spots" of AuNPRs. Fluorescence enhancement of fluorophores can be realized owing to the larger and stronger electromagnetic fields located at the sharp tips of AuNPRs than those on spherical particles and nanorods.

Near-Infrared-Fluorescent Probes for Bioapplications Based on Silica-Coated Gold Nanobipyramids with Distance-Dependent Plasmon-Enhanced Fluorescence.

Optical antennas with anisotropic metal nanostructures are widely used in the field of fluorescence enhancement based on localized surface plasmons (LSPs). They overcome the intrinsic defects of low brightness of near-infrared (NIR) dyes and can be used to develop sensitive NIR sensors for bioapplications. Here, we demonstrate a novel NIR plasmon-enhanced fluorescence (PEF) system consisting of elongated gold nanobipyramids (Au NBPs) antennas, silica, and NIR dyes.

Solvatochromism, Reversible Chromism and Self-Assembly Effects of Heteroatom-Assisted Aggregation-Induced Enhanced Emission (AIEE) Compounds.

Two compounds, 9,10-bis[2-(quinolyl)vinyl]anthracene (BQVA) and 9,10-bis[2-(naphthalen-2-yl)vinyl]anthracene (BNVA), have been synthesised and investigated. Both of them have aggregation-induced enhanced emission (AIEE) properties. Heteroatom-assisted BQVA shows solvatochromism, reversible chromism properties and self-assembly effects.

Dual-emission fluorescent sensor based on AIE organic nanoparticles and Au nanoclusters for the detection of mercury and melamine.

A novel dual-emission ratiometric fluorescence probe is designed and developed by linking two parts, positively charged aggregation-induced emission (AIE) organic fluorescence nanoparticles (OFNs) as the reference and negatively charged Au nanoclusters (Au NCs) as the response, by electrostatic attraction for the first time. This probe can be used for not only visual but quantitative determination of Hg(2+) as well as melamine, because red fluorescence of Au NCs can be quenched by mercury ions and recovered by melamine, due to the strong affinity metallophilic Hg(2+)-Au interaction and stronger affinity Hg(2+)-N. During this process, the green fluorescence of AIE-OFNs remains constant owing to the protection of ε-polylysine (ε-Ply).

Aggregation-induced emission compounds as new assisted matrices for laser desorption/ionization time-of-flight mass spectrometry.

Here, N,N'-bis(4-hydroxylsalicylidene)-p-phenylenediamine (BSPD-OH), N,N'-bis(4-methoxylsalicylidene)-p-phenylenediamine (BSPD-OMe) and N,N'-bis(salicylidene)-p-phenylenediamine (BSPD), which belong to the same category of aggregation-induced emission (AIE) compounds based on Schiff base reactions, were synthesized and applied as new matrices in the analysis of small molecules by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). This type of AIE compounds can be good MALDI matrices. Conventional organic matrices often produce large amounts of matrix ions, hindering the analysis of low molecular weight (LMW) compounds.

Distinguish cancer cells based on targeting turn-on fluorescence imaging by folate functionalized green emitting carbon dots.

Developing efficient methods for visual detection of cancer cells has the potential to contribute greatly to basic biological research and early diagnosis of cancer. Here, we report facile and one-step synthesis of green fluorescence carbon dots (CDs) with the help of a new passivating agent--poly(acrylate sodium) (PAAS). Based on the as-prepared CDs, a novel turn-on fluorescence probe was designed for targeting imaging of cancer cells via hydrogen-bond interaction between folic acid and CDs (FA-CDs).

Color- and morphology-controlled self-assembly of new electron-donor-substituted aggregation-induced emission compounds.

Four electron-donor-substituted aggregation-induced emission (AIE) compounds, N,N'-bis(4-methoxylsalicylidene)-p-phenylenediamine (BSPD-OMe), N,N'-bis(4-methylsalicylidene)-p-phenylenediamine (BSPD-Me), N,N'-bis(salicylidene)-p-phenylenediamine (BSPD), and N,N'-bis(4-hydroxylsalicylidene)-p-phenylenediamine (BSPD-OH), are designed and synthesized. They are all found to exhibit controlled self-assembly behaviors and good thermal properties. By changing the terminal electron-donor groups, they are controlled to self-assemble into three emission colors (green, yellow, and orange) and four morphologies (microblocks, microparticles, microrods, and nanowires) in THF/water mixtures.

Multifunctional core-shell upconversion nanoparticles for targeted tumor cells induced by near-infrared light.

Here we synthesize silica-coated NaYF:Yb/Er nanocomposites with a photosensitizer hypericin covalently bound to silica shells (UCNPs@SiO@hypericin) successfully, exhibiting precise size-control, good water dispersity and excellent biocompatibility. Under near-infrared light (NIR) irradiation, UCNPs convert NIR light to strong green light which agrees well with the absorbance peak of the photosensitizer hypericin, and triggers hypericin to generate singlet oxygen effectively. The cell apoptosis studies by flow cytometry, fluorescence microscope imaging with Annexin V-FITC/PI and caspase-3 western blotting demonstrate that UCNPs@SiO@hypericin-FA displays outstanding performance in the induction of apoptosis of Hela cells and HepG2 cells under NIR light irradiation for a short time.

Design and application of anthracene derivative with aggregation-induced emission charateristics for visualization and monitoring of erythropoietin unfolding.

Erythropoietin (EPO) is an attractive protein-unfolding/folding model because of its high degree of unfolding and folding reversibility and intermediate size. Due to its function for regulating red blood cell production by stimulating late erythroid precursor cells, EPO presents obvious values to biological research. A nonemissive anthracene derivative, that is 9,10-bis[4-(3-sulfonatopropoxyl)-styryl]anthracene sodium salt (BSPSA), with aggregation-induced emission (AIE) charateristics shows a novel phenomenon of AIE when EPO is added.

[Effects of two kinds of allelochemicals on photosynthesis and chlorophyll fluorescence parameters of Solanum melongena L. seedlings].

In a culture experiment, the effects of different concentration 2,6-bis (1, 1-dimethylethyl) phenol and 1,2-benzodicarboxylic dimethyl ester on the photosynthesis and chlorophyll fluorescence characteristics of eggplant seedlings were studied, and the results showed that these two allelochemicals were the barriers of chlorophyll content, net photosynthetic rate (Pn), and stomatal conductance (Gs). The intercellular CO2 concentration (Ci) decreased in the former period, and then increased. The allelochemicals increased initial fluorescence (Fo), but decreased maximum photochemical efficiency of PS II (Fv/Fm), quantum efficiency of non-cyclic electron transport of PS II (phi(PSII)), photochemical quenching ((qP) and antenna conversion efficiency (Fv'/Fm' ).