Heavy metals detection using biosensor cells of a novel marine luminescent bacterium Vibrio sp. MM1 isolated from the Caspian Sea.

Monitoring and assessing toxic materials which are being released into the environment along with wastewater is a growing concern in many industries. The current research describes a highly sensitive and rapid method for the detection of toxic concentrations of heavy metals in aquatic environments. Water samples were collected from southern coasts of the Caspian Sea followed by screening of luminescent bacteria. Phylogenetic analysis, including gene sequence of 16S rRNA, and biochemical tests were performed for identification of the isolate. Luminescence activity was tested and measured after treatment of the isolate with different concentrations of heavy metals and reported as EC50 value for each metal. A luminous, gram negative bacterium with the shape of a curved rod was isolated from the Caspian Sea. Biochemical tests and 16S rRNA gene sequence analysis indicated that the isolate MM1 had more than 99% similarity to Vibrio campbellii. The novel isolate is able to emit high levels of light. Bioluminescence inhibitory assay showed that the Vibrio sp. MM1 had the highest sensitivity to zinc and the lowest sensitivity to cadmium; EC50 values were 0.97mgl-1 and 14.54mgl-1, respectively. The current research shows that even low concentrations of heavy metals can cause a detectable decline in luminescence activity of the novel bacterium Vibrio sp. MM1; hence, it makes a good choice for commercial kits for the purpose of monitoring toxic materials.

The role of fatty acids on ICSI outcomes: a prospective cohort study.

BACKGROUND: Our objective was to determine the effect of fatty acids (FAs) in serum and follicular fluid (FF) on fertilization and intracytoplasmic sperm injection (ICSI) outcomes. METHODS: One hundred five women aged 18-38 years undergoing ICSI were recruited in this prospective cohort study. oocyte and emberyo quality was morphologically assessed. FAs in serum and FF were analyzed, using gas chromatography-mass spectrometry (GC-MS). RESULTS: The mean number of mature oocytes was associated with serum levels of oleic acid (r = 0.58; P = 0.002). There were negative correlations between metaphase II oocytes and FF levels of stearic acid (r = -0.19; P = 0.04) and linolenic acid (r = -0.37; P = 0.004). According to the obtained Spearman's correlation coefficients, serum levels of stearic, palmitoleic and tricosanoic acids were positively correlated with the percent of germinal vesicle (GV) stage oocyte. The mean serum level of eicosapentaenoic acid was significantly higher in pregnant women than in non-pregnant patients (P = 0.006). Good quality embryos' percentages were negatively correlated with the concentrations of palmitic acid (r = -0.22; P = 0.02). After adjusting the effects of body mass index and age, total FAs were found to have a significant effect on the odds of having high-quality oocytes (percentage of oocytes > 80%; odds ratio =2.55; P = 0.054). CONCLUSION: Particular FAs affect oocyte maturation and implantation. Apparently, while higher FF levels of saturated FAs, especially palmitic and stearic acids, observed in some metabolic contexts have harmful effects on oocyte maturation and implantation, such effects can be counteracted and developmental competence can be enhanced (at least in vitro) by the presence of unsaturated FAs, e.g. oleic and eicosapentaenoic acids.

Determination of Glucose and Cholesterol Using a Novel Optimized Luminol- CuO Nanoparticles-H2O 2 Chemiluminescence Method by Box-Behnken Design.

In this study, a simple, rapid and sensitive luminol-CuO nanoparticles-H2O2 chemiluminescence (CL) method has been proposed for determination of glucose and cholesterol in plasma. Response surface methodology (RSM) based on Box-Behnken design (BBD) was used to optimize the most important operating variables (solution pH effect and the CL reagents concentration) of luminol CL system. In optimum conditions, it was found that CuO nanoparticles (NPs) could enhance the CL intensity and the method sensitivity towards evaluation of trace amount of glucose and cholesterol. Under the optimal conditions, there is a good linear relationship between the luminol-CuO NPs - H2O2 relative CL intensity and the concentration over the range of 1.2 × 10(-6)-1.0 × 10(-3) M (R (2) = 0.9991) for glucose and 2.5 × 10(-5)-CuO NPs7.17 × 10(-3) M (R (2) = 0.9968) for cholesterol and with a 3σ detection limit of 7.1 × 10(-7) and 6.4 × 10(-6) M, respectively. The relative standard deviations (RSD) < 3.3% were obtained.

Imidazolium-based ionic liquid derivative/Cu(II) complexes as efficient catalysts of the lucigenin chemiluminescence system and its application to H2O 2 and glucose detection.

The effects of six synthetic imidazolium-based ionic liquids (ILs) on the Cu(II)-catalyzed chemiluminescence of lucigenin (Luc-CL) in the pH range 6.0-11 were investigated. Preliminary experiments found that the CL emission was strongly enhanced or inhibited in the presence of the ILs. The degree of enhancement or inhibition of the CL intensity in the presence of each IL was related to the molecular structure of the IL, the medium used, and the pH. The maximum enhancement of the CL intensity was observed at pH 9.0 (amplification factor = 443). This decrease in the pH at which maximum CL enhancement occurred and the substantial signal amplification of the Luc-CL may be related to a strong interaction between Cu(II) and the imidazolium ring of superior ILs at this pH. Additionally, the formation of IL microdomains in semi-aqueous media permitted more solubility of the product yielded by the Luc-CL reaction (N-methylacridone), which could increase the CL intensity. To obtain consistent data on the catalytic efficiency of Cu(II) in the presence of various ILs as well as the corresponding CL emission intensities, fluorescence quantum yields (Φ F) of lucigenin were measured under the same conditions. Comparison of the data pointed to the mechanism that controls the properties of Luc-CL in the presence of the Cu(II)/IL complexes. Based on the catalytic effect of the Cu(II)/IL complex and the measurement of the enzymatically generated H2O2, a novel, simple, and sensitive CL method for determining glucose with a detection limit (LoD) of 6.5 µM was developed. Moreover, this method was satisfactorily applied to the determination of glucose in human serum and urine samples. Graphical Abstract The lucigenin chemiluminescence assay for H2O2 and glucose using imidazolium-based ionic liquid derivatives/Cu(II) complexes as efficient catalysts at pH 9.0.

Nanostructured rhodamine B/aluminosilicate extracted sugarcane bagasse modified with tobacco-derived carbon quantum dot as ratiometric fluorescence probe for determination of tetracycline.

Tetracycline (TC), as a widely used antibiotic, is very useful in treating bacterial infections. However, its residues in animal foodstuffs can enter the human body through the food cycle and causes severe and chronic diseases. On the other hand, due to its weak non-biodegradability, it is considered a threat to the environment. In this regard, the development of sensing methods to detect and measure TC is need of the hour. Herein, a dual-emission fluorescence sensor based on porous aluminosilicate structure (ASS) with rough surface hexagonal shape morphology and pore diameter less than 2 nm was prepared. The porous AAS was modified by post-modification method with blue carbon dots (CDT) and rhodamine B (RB) as two fluorophores to develop the ratiometric fluorescence (RF) sensor (CDT-AAS/RB). Nanostructured CDT-AAS/RB emitted two resolved peaks at 445 and 585 nm , which were dramatically quenched in the presence of TC. The RF sensor, with excellent sensitivity, was able to measure TC over the linear range of 0.001-150 µM with a limit of detection of 5.4 nM in the aqueous phosphate buffer. Moreover, the AAS component granted high selectivity and anti-interference ability to the sensor. In addition, the stability of the sensor was greatly improved due to the non-accumulation of CDT nanoparticles and RB molecules in the presence of the AAS. The proposed method was able to determine TC in complex real samples with satisfactory recovery, and the obtained results were validated with standard high-performance liquid chromatography technique.

A liter scale synthesis of hierarchically mesoporous UiO-66 for removal of large antibiotics from wastewater.

The presence of antibiotics in water sources is a significant concern due to their potential environmental impact and the risks to human health. In the present research, hierarchically mesoporous UiO-66 (HP-UiO-66) with a high surface area (1011 m2/g) and large pore volume was synthesized using the reflux method on the liter scale. The successful synthesis was confirmed by FT-IR, XRD, FESEM/EDS, N2-adsorption/desorption, and zeta potential techniques. The HP-UiO-66 was utilized to remove two large structure antibiotics, chlortetracycline hydrochloride (CTC), and oxytetracycline (OTC). Box Behnken design was used to investigate the factors affecting the removal process and the interactions between them. The maximum adsorption capacities for OTC and CTC antibiotics were 252.9 mg/g and 234.2 mg/g at 35 °C, respectively. The sum of the normalized error method was applied to the analysis of various error functions in the nonlinear fitting of equilibrium and kinetic data. The CTC and OTC adsorption kinetic followed a fractal-like pseudo-second-order model. The Langmuir isotherm fitted well to adsorption data. The results demonstrate that HP-UiO-66 can be used as a recyclable and efficient adsorbent for large molecule antibiotics removal.

The study of kinetic of silver catalytic degradation of phoxim.

In this study, we scrutinized the degradation process of phoxim in the presence of Ag+ ions, maintaining a 1:1 molar ratio under diverse temperature conditions. Phoxim was chosen as the model compound to devise experimental methodologies that would shed light on the kinetic and degradation pathways within a time span of 0 to 184 min across varying temperatures. The Arrhenius equation was harnessed to ascertain the activation energies linked with the degradation of phoxim. The application of the Arrhenius equation enables the computation of the reaction constant at a given temperature, thereby paving the way for the prediction of phoxim concentrations at different temperatures. The second-order rate constant for the reaction was observed to lie within the range of 0.035 to 0.128 L mol-1min-1, and the half-life of the reaction fluctuated between 5.2 and 17 min across different temperatures.•The study investigates the degradation of phoxim in the presence of Ag+ ions at various temperatures.•The Arrhenius equation was used to calculate the activation energies and predict phoxim concentrations at different temperatures.•The second-order rate constant for the reaction ranged from 0.035 to 0.128 L mol-1min-1, with the half-life varying between 5.2 and 17 min.

Determination of epinephrine in pharmaceutical formulation by an optimized novel luminescence method using CdS quantum dots as sensitizer.

In this article, a novel chemiluminescence method using water-soluble CdS quantum dots (QDs) as sensitizers is proposed for the chemiluminometric determination of epinephrine. The method is based on the quenching effect of epinephrine on the chemiluminescence emission generated by the mixing of CdS quantum dots (QDs) with hydrogen carbonate (HCO3(-)) in the presence of hydrogen peroxide (H2O2) in an alkaline medium. The optimization of variables influencing the chemiluminescence response of the method has been carried out by using experimental design. Under the optimal conditions, there is good linear relationship between the relative chemiluminescence intensity and the concentration of epinephrine over the range of 5 × 10(-9)-1 × 10(-6) molL(-1) with a 3σ detection limit of 5 × 10(-11) molL(-1). The method has been successfully applied to the determination of epinephrine in pharmaceutical formulation and the recovery test was done in human urine.

New strategy to enhance heavy metal ions removal from synthetic wastewater by mercapto-functionalized hydrous manganese oxide via adsorption and membrane separation.

The development of efficient materials and methods for the elimination of heavy metals contamination from water bodies is increasingly demanded as these toxic cations can acute diseases to humans or make serious threat to the environment. The aim of this research is to evaluate the effectiveness of the organosilane coupling agent for the modification of hydrous manganese oxide and the application of the functionalized nanoadsorbent for the removal of nickel and copper ions from synthetic wastewater samples. The synthesized thiol-functionalized hydrous manganese oxide was characterized in terms of their morphology, surface area, functional groups, surface elemental compositions, and the structural properties. In the adsorption process of Ni(II) and Cu(II), the effective parameters including the initial metal cation concentration (20-150 mg/L), operation temperature (298-318 K), and the contact time at the optimum pH were investigated. The uptake of Ni(II) and Cu(II) ions on the prepared adsorbents followed by the Freundlich isotherm model reveals the heterogeneous adsorption, with the adsorption capacities of 24.96 mg/g and 31.2 mg/g for the modified adsorbent and 23.92 mg/g and 29.6 mg/g for the virgin adsorbent, respectively. Based on the results, both the virgin and the functionalized adsorbents exhibited high affinity to copper ions than nickel in the single-component system. Kinetic experiments of both metal ions clarified that the experimental data was well predicted by pseudo-second-order model and the equilibrium was achieved after 10 min of contact time. Additionally, the incorporation of the as-prepared adsorbents in the electrospun nanofibers membrane matrix showed the promising potential for the removal of metal cations. The nickel and copper removal efficiency by the membranes containing 1.5 wt% of the modified adsorbent was 80% and 89%, respectively which implying that the modified adsorbent could be employed more efficiently in other treatment techniques for the removal of metallic pollutants. The modification of hydrous manganese oxide by the functional mercaptosilane increases the adsorption sites for trapping the metal ions and improves the adsorption capacity, making high capability for the removal of metal ions from the effluent.

Studies of new peroxyoxalate-H2O2 chemiluminescence system using quinoxaline derivatives as green fluorophores.

Quinoxaline derivatives are a great interest as fluorescent emitters for peroxyoxalate chemiluminescence. Reaction of peroxyoxalates such as bis-(2,4,6-trichlorophenyl) oxalate with H(2)O(2) can transfer energy to fluorophore via formation of dioxetanedione intermediate. Two quinoxaline derivatives used as a fluorophore in this study which produce a green light in the chemiluminescence systems. The relationship between the chemiluminescence intensity and concentrations of fluorophore, peroxyoxalate, sodium salicylate and hydrogen peroxide was investigated. Kinetic parameters for the peroxyoxalate-chemiluminescence were also calculated from the computer fitting of the corresponding chemiluminescence intensity/time profiles. It was found that the biphenylquinoxaline can be used as an efficient green fluorescent emitter.

Synthesis of zeolite NaY supported Mn-doped ZnS quantum dots and investigation of their photodegradation ability towards organic dyes.

In this work, Mn-doped ZnS quantum dots capped by L-cysteine (Mn@ZnS/L-cyst) and polyethylene glycol (Mn@ZnS/PEG) and also Mn-doped ZnS on zeolite NaY (Mn@ZnS/Y) were synthesized. These compounds were characterized by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and ultraviolet-visible and fluorescence spectroscopy. Then, the photodegradation ability of these three photocatalysts was investigated for degradation of 4',5'-dibromofluorescein dye under ultraviolet irradiation. In the next stage, the different effective parameters on degradation performance, such as pH, catalyst dosage, and initial dye concentration, were studied. Results demonstrated that the optimum initial concentration was 40 mg L-1 for all three catalysts. The optimum catalyst dosage for both Mn-doped ZnS quantum dots capped by L-cysteine and Mn-doped ZnS on zeolite NaY was 0.017 g L-1 and for Mn-doped ZnS quantum dots capped by polyethylene glycol was 0.033 g L-1. The degradation efficiency of 97% for all three photocatalysts was achieved; therefore, by considering the higher production yield of quantum dots onto zeolite and also the more convenient recovery of the Mn-doped ZnS on zeolite NaY from the solution, it seems synthesis of quantum dots onto the zeolites is a reasonable strategy.

A study of quenching and enhancing effects of some amino acids on peroxyoxalate chemiluminescence of rhodamine 6G.

The quenching effect of l-cysteine, l-methionine on strong chemiluminescence of bis(2,4,6-trichlorophenyl)oxalate-H(2)O(2) system in the presence of rhodamine 6G was studied. The chemiluminescence parameters were evaluated from computer fitting of the resulting intensity-time plots. These systems resulted in Stern-Volmer plots in the quencher concentration range of 4.0 x 10(-6) to 4.0 x 10(-5)M, with K(Q) values of 1.64 x 10(4) and 8.0 x 10(4)M(-1) for l-metionine and l-cysteine, respectively. Also, this study describes the employment of l-histidine as a highly potent signal enhancer in peroxyoxalate chemiluminescence in the presence of rhodamine 6G.

Green synthesis of fluorescent PEG-ZnS QDs encapsulated into Co-MOFs as an effective sensor for ultrasensitive detection of copper ions in tap water.

In this work, a novel and highly fluorescent (FL) metal-organic framework (MOF)-based host-guest hybrid system was developed through encapsulation of polyethylene glycol (PEG)-capped ZnS quantum dots (QDs) into zeolitic imidazolate framework (ZIF)-67 at ambient temperature. This new composite material was characterized by FT-IR, XRD, TEM, UV-Vis absorption and FL spectroscopy, and then exploited as fluorescence sensor for highly sensitive and selective detection of Cu (II) ions in water samples. The as-prepared PEG-ZnS QDs@ZIF-67 nanohybrids took advantages of both accumulation effect in ZIF-67 and FL sensitivity and selectivity in ZnS QDs toward analyte-Cu2+. In this regard, ZIF-67 was treated as absorbents to capture and enrich Cu (II) ions, and ZnS QDs were exploited as tentacle to selectively and sensitively sense the bonding interactions between ZIF-67 and Cu (II) ions, and further transduce these chemical events to the detectable fluorescence signals. By this approach, Cu2+ could be detected in a wide concentration range of 3 to 500 nM with a LOD as low as 0.96 nM. The proposed FL-sensor can be promising in the field of preparation of various QDs@MOFs platforms for application in high-performance optical sensing.

A study of peroxyoxalate-chemiluminescence of 4,4'-bis{[4,6-bis (2-hydroxyethyl)amino-1,3,5-triazin-2-yl]amino}stilbene-2,2'-disulfonic acid-disodium salt as a novel blue fluorescer.

The chemiluminescence arising from the reaction of bis(2,4,6-trichlorophenyl)oxalate (TCPO) with hydrogen peroxide in the presence of brightener 4,4'-bis{[4,6-bis(2-hydroxyethyl)amino-1,3,5-triazin-2-yl]amino}stilbene-2,2'-disulfonic acid-disodium salt (Triazinyl) has been studied. The influence of concentration of TCPO, hydrogen peroxide, Triazinyl, base catalysts and temperature on the resulting chemiluminescence was investigated. The kinetic parameters for the peroxyoxalate-chemiluminescence (PO-CL) of Triazinyl were evaluated from computer fitting of the resulting intensity-time plots. The activation energies, E(a), were evaluated from temperature dependence of the corresponding rise and fall rate constants.

Does different BMI influence oocyte and embryo quality by inducing fatty acid in follicular fluid?

OBJECTIVE: We aimed to assess the effects of obesity-related follicular fluid (FF) fatty acids (FAs) on the number and quality of oocytes, good embryo quality rate, and pregnancy rate. MATERIALS AND METHODS: This prospective cohort study was conducted on 105 infertile women under the age of 38, who underwent intracytoplasmic sperm injection (ICSI) from March 2015 to October 2015. They were grouped into three body mass index (BMI) categories. The fatty acids composition of the FF was analyzed by GC-MS head space method. We studied the FAs correlation with BMI and ICSI outcomes. RESULTS: The distribution of fatty acids did not differ significantly in each BMI group, with the exception for stearic that was marginally significant (p=0.05). The mean number of mature oocytes did not differ significantly between the BMI groups, the percent of Metaphase II (MII) oocytes was inversely associated with the BMI (rs=-0.21, p=0.03). Kruskal-Wallis test showed that the distribution of good quality embryos' percentages were different in at least two categories of studied BMI groups (p=0.009, p=0.02). The mean concentration of palmitic acid was higher in nonpregnant patients for all of the studied BMI classes (p=0.02, p=0.03, p=0.05), however, stearic (p<0.001) and linolenic acids (p=0.01) were higher in nonpregnant normal weight patients. CONCLUSION: Differences in BMI are not associated with the fatty acid composition of the FF. The FF fatty acid possibly affects the outcome of ICSI through the achievement of clinical pregnancy. Therefore, it is essential to provide patients with nutritional counseling before they use assisted reproductive techniques.

cDNA cloning, expression and homology modeling of a luciferase from the firefly Lampyroidea maculata.

The cDNA of a firefly luciferase from lantern mRNA of Lampyroidea maculata has been cloned, sequenced and functionally expressed. The cDNA has an open reading frame of 1647 bp and codes for a 548-residue-long polypeptide. Noteworthy, sequence comparison as well as homology modeling showed the highest degree of similarity with H. unmunsana and L. mingrelica luciferases, suggesting a close phylogenetic relationship despite the geographical distance separation. The deduced amino acid sequence of the luciferase gene of firefly L. maculata showed 93% identity to H. unmunsana. Superposition of the three-dimensional model of L. maculata luciferase (generated by homology modeling) and three dimensional structure of Photinus pyralis luciferase revealed that the spatial arrangements of Luciferin and ATP-binding residues are very similar. Putative signature of AMPbinding domain among the various firefly species and Lampyroidea maculata was compared and a striking similarity was found. Different motifs and sites have been identified in Lampyroidea maculata by sequence analysis. Expression and purification of luciferase from Lampyroidea maculata was carried out using Ni-NTA Sepharose. Bioluminescence emission spectrum was similar to Photinus pyralis luciferase.

A study of quenching effect of sulfur-containing amino acids L-cysteine and L-methionine on peroxyoxalate chemiluminescence of 7-amino-4-trifluoromethylcumarin.

The quenching effect of L-cysteine and L-methionine on strong chemiluminescence of bis-(2,4,6-trichlorophenyl)oxalate-H(2)O(2) system in the presence of 7-amino-4-trifluoromethylcumarin was studied. The chemiluminescence parameters were evaluated from computer fitting of the resulting intensity-time plots. Both systems resulted in Stern-Volmer plots in the quencher concentration range of 6.5 x 10(-5) to 5.2 x 10(-4)M with k(Q) values of 1.15 x 10(4) and 1.28 x 10(4)M(-1) for L-cysteine and L-methionine, respectively.

Sensitive assay of hexythiazox residue in citrus fruits using gold nanoparticles-catalysed luminol-H2O2 chemiluminescence.

A new sensitive chemiluminescence (CL) procedure for the detection of hexythiazox (HXTZ) is presented, based on the quenching effect of the HXTZ in the luminol-H2O2 system using gold nanoparticles (GNPs) as a catalyst. The Box-Behnken design matrix and response surface methodology (RSM) have been applied in designing the experiments for studying the interactive effects of the three most important variables pH, luminol, and H2O2 concentrations on the CL intensity of luminol catalysed by GNPs. Under the optimal conditions, the CL intensity was linear with HXTZ concentration in the range of 0.017-0.42 µg mL(-1), and the limit of detection (LoD) was 0.011 µg mL(-1). The procedure has been successfully applied to the detection of HXTZ residues in citrus fruits and water samples at trace levels. Mean recoveries obtained were between 84.0% and 95.3%, with a repeatability precision of <6%. Meanwhile, the possible mechanism of the inhibited CL intensity was discussed.

Photoimmunological properties of borage in bovine neutrophil in vitro model.

Borage (Echium amoenum fisch) is one of the most commonly used medicinal plants, and has long been used as a traditional herbal medicine for many (non)infectious diseases in Iran. Study on photoredox and photoimmunology of borage is little. Natural immunomodulatory plants with minimal adverse/toxic effects could help boost animal health and, ultimately, public health. To determine the effect of borage on the functions of key circulating innate immune cells, effects of borage extract (BE) on bovine neutrophils (PMN) photoredox and phagocytosis events were evaluated using an in vitro model system. Blood PMN isolated from healthy high yielding dairy cows (n = 8/treatment) were pre-incubated with BE and the impact on phagocytosis-dependent-and-independent cellular chemiluminescence (CL), phagocytosis, killing of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), fluorescence-based PMN H2O2 production and necrosis were assessed. Relative to control (no BE) PMN, treatment with BE significantly increased phagocytosis-dependent-and-independent PMN CL (>10-15% increase). While BE also led to increased PMN H2O2 production, necrosis was also surprisingly higher in these cells. Phagocytosis and killing of both E. coli and S. aureus by PMN treated with BE was substantially higher than that by control PMN. The increased photoimmunobiological events especially intracellular CL, intracellular H2O2 formation, and phagocytic capacity of BE-treated PMN support the potential immunotherapeutic implications of borage and its components for particularly immunocompromised animals and humans.

Quantum dots and ionic liquid-sensitized effect as an efficient and green catalyst for the sensitive determination of glucose.

A novel fluorescence (FL) method using water-soluble CdSe quantum dots (QDs) is proposed for the fluorometric determination of hydrogen peroxide and glucose. Water-soluble CdSe QDs were synthesized by using thioglycolic acid as stabilizer in aqueous solutions. The nanoparticles were structurally and optically characterized by X-ray powder diffraction (XRD), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), UV-Vis absorption spectroscopy, photoluminescence (PL) emission spectroscopy and transmission electron microscope (TEM). Ionic liquid-sensitized effect in aqueous solution was then investigated. In the presence of ionic liquid as catalyst, H2O2 was decomposed into radical that could quench the fluorescence of CdSe QDs more efficiently and rapidly. Then the oxidization of glucose by glucose oxidase was coupled with the fluorescence quenching of CdSe QDs by H2O2 producer with ionic liquid catalyst, which can be used to detect glucose. Therefore, a new FL analysis system was developed for the determination of glucose. Under the optimum conditions, there is a good linear relationship between the relative PL emission intensity and the concentration of glucose in the range of 5.0×10(-7)-1.0×10(-4) M of glucose with a correlation coefficient (R(2)) of 0.9973. The limit of detection of this system was found to be 1.0×10(-7) M. This method is not only simple, sensitive and low cost, but also reliable for practical applications.