Microwave-assisted one-pot synthesis of water-soluble rare-earth doped fluoride luminescent nanoparticles with tunable colors.

Polyethyleneimine (PEI) functionalized multicolor luminescent LaF(3) nanoparticles were synthesized via a novel microwave-assisted method, which can achieve fast and uniform heating under eco-friendly and energy efficient conditions. The as-prepared nanoparticles possess a pure hexagonal structure with an average size of about 12 nm. When doped with different ions (Tb(3+) and Eu(3+)), the morphology and structure of the nanoparticles were not changed, whereas the optical properties varied with doped ions and their molar ratio, and as a result emission of four different colors (green, yellow, orange and red) were achieved by simply switching the types of doping ions (Eu(3+) versus Tb(3) +) and the molar ratio of the two doping ions.

[Biosynthesis of CdS quantum dots in Saccharomyces cerevisiae and spectroscopic characterization].

In the present work, CdS quantum dots (QDs) were successfully biosynthesized at room temperature by using saccharomyces cerevisiae yeast as a carrier. Fluorescence emission spectra, ultraviolet-visible (UV/Vis) absorption spectra, and inverted fluorescence microscope images confirmed that saccharomyces cerevisiae can be used to biosynthesize CdS QDs. The as-prepared CdS QDs show the fluorescence emission peak at 443 nm and emit blue-green fluorescence under UV light (with excitation at 365 nm).

Study on the sonodynamic activity and mechanism of promethazine hydrochloride by multi-spectroscopic techniques.

In this paper, the bovine serum albumin (BSA) was selected as a target molecule, the sonodynamic damage to protein in the presence of promethazine hydrochloride (PMT) and its mechanism were studied by the means of absorption, fluorescence and circular dichroism (CD) spectra. The results of hyperchromic effect of absorption spectra and quenching of intrinsic fluorescence spectra indicate that the ultrasound-induced BSA molecules damage is enhanced by PMT. The damage degree of BSA molecules increases with the increase of ultrasonic irradiation time and PMT concentration.

Spectroscopic investigation on the synergistic effects of ultrasound and dioxopromethazine hydrochloride on protein.

The bovine serum albumin (BSA) was selected as a target molecule, the sonodynamic damage to protein in the presence of dioxopromethazine hydrochloride (DPZ) and its mechanism were studied by means of absorption and fluorescence spectra. The results of hyperchromic effect of absorption spectra and quenching of intrinsic fluorescence spectra indicated that the synergistic effects of ultrasound and DPZ could induce the damage of BSA molecules. The damage degree of BSA molecules increased with the increase of ultrasonic irradiation time and DPZ concentration.

The influence of ultrasound on the fluoroquinolones antibacterial activity.

In this work, the antibacterial effect of fluoroquinolones (FQs) upon Escherichia coli (E.coli) was measured with and without application of 40 kHz ultrasound (US) stimulation. The research results demonstrated that simultaneous application of 40 kHz US apparently enhanced the antibacterial effectiveness of FQs.

Spectroscopic investigation on protein damage by ciprofloxacin under ultrasonic irradiation.

In recent years, sonodynamic activities of many drugs have attracted more and more attention of researchers. The correlative study will promote the development of sonodynamic therapy (SDT) in anti-tumor treatment. In this work, bovine serum albumin (BSA) was used as a protein model to investigate the intensifying effects of ciprofloxacin (CPFX) ultrasonically induced protein damage by UV-vis and fluorescence spectra.

Synthesis and characterization of polymer eight-coordinate (enH2)[YIII(pdta)(H2O)](2)·10H2O as well as the interaction of [YIII(pdta)(H2O)]2(2-) with BSA.

The eight-coordinate (enH2)[YIII(pdta)(H2O)](2)·10H2O (en=ethylenediamine and H4pdta=1,3-propylenediamine-N,N,N',N'-tetraacetic acid) was synthesized, meanwhile its molecular and crystal structures were determined by single-crystal X-ray diffraction technology. The interaction between [Y(III)(pdta)(H2O)]2(2-) and bovine serum albumin (BSA) was investigated by UV-vis and fluorescence spectra. The results indicate that [YIII(pdta)(H2O)]2(2-) quenched effectively the intrinsic fluorescence of BSA via a static quenching process with the binding constant (Ka) of the order of 10(4).

Spectrometric studies on the sonodynamic damage of protein in the presence of levofloxacin.

Taking bovine serum albumin (BSA) as typical molecules, the sonodynamic damage of protein in the presence of Levofloxacin (LVFX) and its mechanism were studied by fluorescence and UV-vis spectra. Various influencing factors such as ultrasonic irradiation time, pH value, ionic strength and solution temperature on the damage of BSA were also discussed. The results showed that ultrasound can enhance the damage of LVFX on BSA.

[Preparation of GSH capped CdSe/CdS core-shell QDs and labeling of human T-lymphocyte].

Two kinds of L-glutathione capped highly fluorescent CdSe/CdS core-shell quantum dots (QDs) emitting green and orange fluorescence at 350 nm excitation were firstly prepared by an aqueous approach and used as fluorescent labels, to link mouse anti-human CD3 which was expressed on human T-lymphocyte. UV-Vis absorption and fluorescence emission spectra of the as-prepared CdSe/CdS core-shell QDs were studied. Compared with the CdSe QDs, a remarkable enhancement in the emission intensity and a red shift of emission wavelength of CdSe/CdS core-shell QDs was observed for the two kinds of QDs emitting green and orange fluorescence.

[Synthesis and characterization of NaYF4 : Yb, Er upconversion fluorescent nanoparticles via a co-precipitation method].

Monodisperse NaYF4 : Yb, Er upconversion fluorescent nanoparticles were firstly synthesized via a co-precipitation method in the presence of diethylenetriamine pentoacetic acid (DTPA). The nanoparticles were characterized by using of X-ray diffraction (XRD), transmission electron microscope (TEM), fluorescence (FL) spectrum, and thermogravimetry-differential scanning calorimetry (TG-DSC) analysis. The as-prepared nanoparticles were uniform, and their size could be controlled in a range of 20 to 120 nm by varying the amount of DTPA.

[Determination of trace copper (II) based on fluorescence quenching of NaGdF4 : Eu nanoparticles].

Water-soluble NaGdF4 : Eu fluorescent nanoparticles modified by citrate were synthesized by hydrothermal method with stable fluorescent properties. It was found that the fluorescence of the solution of as-prepared particles could be quenched by Cu2+, and thus a new mathod to determine trace Cu2+ using NaGdF4 : Eu as fluorescent probe was established. A pH 10.

[Determination of DNA using Eu-PPA as fluorescence probe by time-resolved fluorescence].

In the Tris-HCl buffer solution, europium ion combined with pipemidic acid (PPA) to form a Eu-PPA complex. The fluorescence intensity was dramatically enhanced when herring sperm DNA was added in the Eu-PPA system. Furthermore, the fluorescence intensity was increased linearly with the concentrations of added DNA within a proper range.

Immunoassay of goat antihuman immunoglobulin G antibody based on luminescence resonance energy transfer between near-infrared responsive NaYF4:Yb, Er upconversion fluorescent nanoparticles and gold nanoparticles.

Near-infrared (NIR) light can penetrate biological samples and even tissues without causing sample damage and avoid autofluorescence from biological samples in fluorescence detection. Thus, a luminescence resonance energy transfer (LRET)-based immunoassay that can be excited by NIR irradiation is a promising approach to the analysis of biological samples. Here we demonstrate the use of NIR-to-visible upconversion nanoparticles (UCNPs) as an energy donor, which can emit a visible light upon the NIR irradiation, and gold nanoparticles (Au NPs) as an energy acceptor, which can absorb the visible light emitted from the donor, to develop a sandwich-type LRET-based immunoassay for the detection of goat antihuman immunoglobulin G (IgG).

Immunolabeling and NIR-excited fluorescent imaging of HeLa cells by using NaYF(4):Yb,Er upconversion nanoparticles.

Upconversion fluorescent nanoparticles can convert a longer wavelength radiation (e.g., near-infrared light) into a shorter wavelength fluorescence (e.

[Synthesis and absorption spectra properties of Au-Ag alloy nanoparticles using gallic acid as reductant].

Gold-silver alloy nanoparticles with a homogeneous size distribution and good stability were synthesized in aqueous solution by one-step reduction with gallic acid as reductant in the absence of other stabilizers for the first time. The absorption spectra of as prepared gold-silver alloy nanoparticles under different reaction temperatures and with various gold-silver mole ratios were studied. The absorption spectra exhibit only one single peak with the maximum wavelength located between the absorption peaks of Au nanoparticles and Ag nanoparticles, however, the absorption spectrum of the physical mixtures of Au nanoparticles and Ag nanoparticles exhibits two absorption peaks coming from their corresponding monometallic metal nanoparticles, suggesting primarily the formation of the alloy nanoparticles.

A glass microfluidic chip for continuous blood cell sorting by a magnetic gradient without labeling.

This paper presents a microfluidic chip for highly efficient separation of red blood cells (RBCs) from whole blood on the basis of their native magnetic properties. The glass chip was fabricated by photolithography and thermal bonding. It consisted of one inlet and three outlets, and a nickel wire of 69-microm diameter was positioned in the center of a separation channel with 149-microm top width and 73-microm depth by two parallel ridges (about 10 microm high).

[Applications of quantum dots to biological probes].

Quantum dots (QDs) have shown unique optical properties compared with traditional organic dyes. Now, more and more attention has been paid to them, especially in the fields of biological medicine and materials. Much work about QDs application in biology has been done by many researchers.

[Study of autofluorescence spectra of protoporphyrin IX in human serum].

The fluorescence spectra of protoporphyrin IX (PPIX) solutions and human serum samples were measured and analyzed under physiological conditions. The experimental results showed that the fluorescence of PPIX in human serum was mainly derived from PPIX-serum albumin complex. Moreover, the effects of serum albumin and PPIX on the PPIX emission fluorescence were also investigated.

[Spectroscopy study of aqueous CdTe quantum dots synthesized by microwave irradiation method].

Water-soluble CdTe nanocrystals capped with cysteamine were synthesized rapidly in aqueous solution by microwave irradiation with controllable temperature. Absorption and fluorescence spectra showed that these prepared CdTe quantum dots had good optical properties. The structure and diameter were characterized by the transmission electron microscopy (TEM) and X-ray powder diffraction (XRD).

[Determination of As, Pb, Sn, Sb and Bi in high temperature iron and nickel-based alloy by graphite furnace atomic absorption spectrometry combined with liquid-liquid extraction].

A method was developed for the determination of As, Pb, Sn, Sb and Bi in high temperature iron and nickel-based alloy by graphite furnace atomic absorption spectrometry combined with liquid-liquid extraction. These elements formed complexes with I- ions and were subsequently extracted into MIBK to be separated from matrix elements. The effects of remnant matrix elements were studied in detail.