CdSe Quantum Dots Decorated by 3-Aminobenzeneboronic Acid as Fluorescence Probe for Glucose

2011 ◽  
Vol 306-307 ◽  
pp. 1338-1341
Author(s):  
Shao Wei Wang ◽  
Xia Ona Zhang ◽  
Jing Hua Yu
Keyword(s):  
Quantum Dots ◽  
Fluorescence Probe ◽  
High Sensitivity ◽  
Cdse Quantum Dots ◽  
Optimal Conditions ◽  
Cdse Qds ◽  
Relative Standard ◽  
Sensitivity And Selectivity

A simple route to the production of high-quality CdSe quantum dots (QDs) is presented. The characterization of CdSe QDs was measured by Zetasizer Nano ZS, ultraviolet-visible spectoscopy and fluorospectrophotometer. The CdSe QDs were decorated by 3-Aminobenzeneboronic acid to obtain good fluorescent characteristic. Under the optimal conditions, the decreased normalized absorbance was linear to the concentration of glucose from 1.0×10−7 to 2.9×10−6 mol·L-1with a detection limit of 5.0´10-8mol·L-1. The relative standard deviation (RSD) for the determination of 1.0×10-7mol·L-1was 1.4 % by 11 replicate determination. In this paper, the fluorescent behavior of glucose with the decorated CdSe QDs was studied, and it is found that the system has a high sensitivity and selectivity for analysis of glucose.

Synthesis and Application of p-Carboxyarsenazo for Spectrophotometric Determination of Cu(II) in Environment Water

2013 ◽  
Vol 830 ◽  
pp. 298-301 ◽  
Author(s):  
Lin Gao ◽  
Yan Hua Li ◽  
Sheng Jie Chen ◽  
Fang Chen ◽  
Yuan Fang Zhang ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Water Samples ◽  
Absorption Maximum ◽  
High Sensitivity ◽  
Molar Absorptivity ◽  
Buffer Solution ◽  
Relative Standard ◽  
Sensitivity And Selectivity ◽  
Color Reagent

p-Carboxyarsenazo (CASA) color reagent was synthesized by simple diazotization reaction, and the chromomeric reaction between CASA with Cu(Ⅱ) has been studied by spectrophotometry. In pH=4.6 NaAc-HAc buffer solution, Cu(Ⅱ) reacted with CASA to form a red complex and exhibits an absorption maximum at 614 nm, Beer’s law is obeyed for 0-160 μg/L of copper in solution, the apparent molar absorptivity obtained is 1.57×104 L/(mol.cm), and the relative standard deviation (R.S.D.) is 1.6%. The proposed method exhibited high sensitivity and selectivity for Cu(Ⅱ). The results obtained by this method in the determination of environment water samples were accurate, sensitive and repeatable

Study on Synthesis and Characterization of a Fluorescence Probe and its Application for Determination of Superoxide Anion Radical

2011 ◽  
Vol 393-395 ◽  
pp. 1483-1487 ◽  
Author(s):  
Yong Qiang Zhao ◽  
Hong Lin ◽  
Lai Hao Li ◽  
Xian Qing Yang ◽  
Shu Xian Hao ◽  
...  
Keyword(s):  
Fluorescence Intensity ◽  
Superoxide Anion ◽  
Anion Radical ◽  
Fluorescence Probe ◽  
High Sensitivity ◽  
Superoxide Anion Radical ◽  
Synthetic Product ◽  
Pyrogallol Autoxidation

A novel Schiff base, 2-(Salicylideneamino)pyridine (2-SAP) synthesized by 2-aminopyridine and salicylaldehyde was used as a fluorescence probe to determine superoxide anion radical (O2•-) in this study. The synthetic product was characterized by IR, 1H-NMR and GC-MS methods. A fluorescence quenching reaction occurs between 2-SAP and O2•-, and the fluorescence intensity decreased significantly. The effect of pyrogallol concentration (2.0×10-5 M to1.0×10-3 M) was discussed in this study. In the range from 2.0×10-5 M to 1.0×10-4 M, relative fluorescence intensity (y) and pyrogallol concentration (x) shown a good linear relationship, y=37.801x+76.854, r=0.993. Based on this phenomenon, the O2•- generated by pyrogallol autoxidation could be determined simply with high sensitivity.

Atomic absorption determination of Hg (II), Cd (II), and As (III) in natural and waste water after preliminary group preconcentration

2019 ◽  
Vol 85 (2) ◽  
pp. 12-16
Author(s):  
I. V. Saunina ◽  
E. N. Gribanov ◽  
E. R. Oskotskaya
Keyword(s):  
Waste Water ◽  
Atomic Absorption ◽  
High Sensitivity ◽  
Distribution Coefficients ◽  
Neutral Medium ◽  
Atomic Absorption Determination ◽  
Absorption Determination ◽  
Relative Standard ◽  
Preliminary Group

The sorption of Hg (II), Cd (II), and As (III) by natural aluminosilicate is studied. It is shown that the mineral absorbs those toxicants in a rather wide pH range, quantitative extraction of analytes being achieved in a neutral or close to neutral medium (pH values range within 7.0 - 8.0; 6.3 - 7.5; 7.4 - 8.5 for Hg (II), As (III), and Cd (II), respectively). The effect of the time of phase contact on the degree of extraction of elements is shown. The sorption capacity of the mineral in optimal conditions of the medium acidity (0.06 mmol/g for mercury, 0.31 mmol/g for cadmium, and 0.52 mmol/g for arsenic) is determined. The distribution coefficients attain values of aboutnX 103-nX 104. A new combined method for determination of Hg (II), Cd (II), and As (III) in natural and waste water is developed and tested. The method consists in a preliminary group sorption concentration of the analytes by aluminosilicate, desorption of the analytes from the surface of the mineral and their subsequent atomic absorption determination. The correctness of the method is verified in analysis of spiked samples. The method is easy to use and exhibits high sensitivity, reproducibility and accuracy of analyte determination. The relative standard deviation does not exceed 0.13. Economic availability and possibility of using domestic sorption materials are the important advantages of the proposed procedure which can be used in the practice of laboratories monitoring the quality and safety of environmental objects.

Graphene quantum dots supported by graphene oxide as a sensitive fluorescence nanosensor for cytochrome c detection and intracellular imaging

2017 ◽  
Vol 5 (31) ◽  
pp. 6300-6306 ◽  
Author(s):  
Lin Cao ◽  
Xiangqing Li ◽  
Lixia Qin ◽  
Shi-Zhao Kang ◽  
Guodong Li
Keyword(s):  
Quantum Dots ◽  
Graphene Oxide ◽  
Cytochrome C ◽  
Graphene Quantum Dots ◽  
A549 Cells ◽  
High Sensitivity ◽  
Fluorescence Sensor ◽  
Intracellular Imaging ◽  
New Class ◽  
Sensitivity And Selectivity

A new class of Cyt c detection fluorescence sensor based on graphene quantum dots supported by graphene oxide has been facilely developed. The sensor shows a high sensitivity and selectivity for Cyt c detection, and further exhibits favorable intracellular imaging in A549 cells.

L-cysteine functionalized graphene quantum dots for sub-ppb detection of As (III)

2021 ◽  
Author(s):  
Md. Farhan Naseh ◽  
Neelam Singh ◽  
Jamilur R. Ansari ◽  
Ashavani Kumar ◽  
Tapan Sarkar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Room Temperature ◽  
Graphene Quantum Dots ◽  
Optical Characterization ◽  
Functionalized Graphene ◽  
Transmission Electron ◽  
Sensitivity And Selectivity ◽  
Structural Characterizations

Abstract Here, we report functionalized graphene quantum dots (GQDs) for the optical detection of arsenic at room temperature. GQDs with the fluorescence of three fundamental colors (red, green, and blue) were synthesized and functionally capped with L-cysteine (L-cys) to impart selectively towards As (III) by exploiting the affinity of L-cys towards arsenite. The optical characterization of GQDs was carried out using UV-Vis absorption spectroscopy, Fourier transform infrared spectroscopy, and fluorescence spectrometry and the structural characterizations were performed using transmission electron microscopy. The fluorescence results showed instantaneous quenching in intensity when the GQDs came in contact with As (III) for all test concentrations over a range from 0.025 ppb to 25 ppb, which covers the permissible limit of arsenic in drinking water. The experimental results suggested excellent sensitivity and selectivity towards As (III).

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