scholarly journals Fluorescent Sensors Based on Organic Polymer-Capped Gold Nanoparticles for the Detection of Cr(VI) in Water

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Na Wang ◽  
Liangchen Wang ◽  
Hong Yang ◽  
Tingting Xiong ◽  
Shangping Xiao ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Redox Reactions ◽  
Inner Filter Effect ◽  
Potential Method ◽  
Fluorescent Sensors ◽  
Organic Polymer ◽  
Buffer Solution ◽  
Ph Values ◽  
Internal Electron ◽  
Interference Study

“Turn-off” fluorescent sensors for Cr(VI) have been fabricated based on organic polymer-capped gold nanoparticles. The fluorescence intensity, as well as the response behavior of the sensors, is dependent on the pH values of buffer solution and dilution amounts of the sensors. When diluted 50 times with pH 2.0 buffer solution, the sensors show good linear responses toward Cr(VI) at concentrations between 2.8–5.9 μM and 5.9–29 μM. The calculated detection limit is 0.63 μM (S/N=3). The interference study and real sample assays exhibit satisfying selectivity and reliability results. Furthermore, the quenched intensity of fluorescence could be recovered by Fe(II) ion, which provides a potential method to detect Fe(II) ions. The quenching and recovering mechanisms have also been investigated. It is suggested that the quenching mechanism is based on the combined effects of internal electron transfer and the inner filter effect. Finally, the recovering mechanism is based on the redox reactions between the Cr(VI) and Fe(II) ions.

Synthesis of Novel Vanadium Oxide Nanotubes and Nanofibers

2002 ◽  
Vol 740 ◽  
Author(s):  
Samuel T. Lutta ◽  
Hong Dong ◽  
Peter Y. Zavalij ◽  
M. Stanley Whittingham
Keyword(s):  
Thermal Analysis ◽  
Vanadium Oxide ◽  
Electrochemical Behavior ◽  
Redox Reactions ◽  
Sol Gel ◽  
Vanadium Oxides ◽  
Organic Polymer ◽  
Fibrous Morphology ◽  
Surfactant Templates ◽  
Vanadium Oxide Nanotubes

ABSTRACTWe are exploring the synthesis and properties of structured vanadium oxides mainly nanotubes and nanorods. Nanotubes initially formed with surfactant templates have been readily exchanged with simple cations without change of the basal-plane structure. These compounds contain d-like vanadium oxide layers with the vanadium in VO6 octahedra. This structure is particularly suitable for redox reactions. In this paper we report on synthesis of vanadium oxide, (NH4)xV2O5-d·nH2O rods using organic polymer as template. This compound has been synthesized by sol-gel reaction and subsequent hydrothermal treatment. TGA, SEM, XRD and FTIR were used to characterize this compound. Thermal analysis of this compound shows that the fibrous morphology is maintained when it is heated in nitrogen and oxygen above 300 °C. However, in both cases the size of the fibers decreases. Performance of this compound as cathode material in secondary electrolyte has been investigated using LiPF6 as electrolyte. A capacity of 140 mAh/g was obtained which remained fairly constant with up to at least 10 cycles. We also investigated electrochemical behavior of thermal products.

Bioceramic Hydroxyapatite Granules for Purification of Biotechnological Products

2011 ◽  
Vol 284-286 ◽  
pp. 1764-1769 ◽  
Author(s):  
Vitalijs Lakevics ◽  
Janis Locs ◽  
Dagnija Loca ◽  
Valentina Stepanova ◽  
Liga Berzina-Cimdina ◽  
...  
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Phosphate Buffer ◽  
Bovine Serum ◽  
Phosphate Buffer Solution ◽  
Sorption Process ◽  
Buffer Solution ◽  
Ph Values ◽  
Bovine Serum Albumin Adsorption ◽  
Albumin Adsorption

Sorption experiments of bovine serum albumin (BSA) on hydroxyapatite (HAp) ceramic granules, prepared at three temperatures 900°C, 1000°C and 1150°C were performed at room temperature 18,6 °C and phosphate buffer, pH 5,83; 6.38 and 7,39. Thermal treatment contributed to the decrease of bovine serum albumin immobilization indicating that sorption process depended on HAp ceramics specific surface area and pH values of phosphate buffer solution. However, it was confirmed that granule size was also an important parameter for bovine serum albumin adsorption. As a result of these experiments, the most appropriate adsorption conditions and phosphate buffer pH values influence on to BSA sorption were analyzed.

scholarly journals Polyaniline-Invertase-Gold Nanoparticles Modified Gold Electrode for Sucrose Detection

2015 ◽  
Vol 15 (3) ◽  
pp. 226-233 ◽  
Author(s):  
Fitriyana Fitriyana ◽  
Fredy Kurniawan
Keyword(s):  
Gold Nanoparticles ◽  
Gold Electrode ◽  
Sucrose Solution ◽  
Sucrose Concentration ◽  
Phosphate Buffer Solution ◽  
Layer By Layer ◽  
Buffer Solution ◽  
Solution Ph ◽  
Active Materials ◽  
Aniline Polymerization

Sucrose sensor has been made by deposited the active materials on the surface of gold electrode. The active materials, i.e. polyaniline (PANI), invertase and gold nanoparticles, were deposited step by step. Aniline polymerization were conducted electrochemically at potential -500 to 1000 mV using voltammetry method with sweep rate 50 mV/s for 20 cycles in HCl solution pH 1.5. The modified electrode obtained was immersed in invertase 1 M phosphate buffer solution pH 6. The invertase trapping in polyaniline was performed using the same condition as aniline polymerization. Then, gold nanoparticles were deposited on the polyaniline-invertase modified gold electrode using Layer by Layer (LbL) technique. The polyaniline-invertase-gold nanoparticles modified gold electrode obtained was used to measure sucrose solution. Electrochemical signal of polyaniline (PANI)-invertase-gold nanoparticles modified gold electrode is increase with sucrose concentration. The sensitivity and detection limit of the electrode are 0.4657 µA mm-2 mM-1 and 9 µM, respectively. No electrochemical interference signals from fructose and glucose have been observed in the sucrose measurement.

Dual mode detection of amifostine based on gold nanoparticles and sulfanilic acid functionalized graphene quantum dots

2018 ◽  
Vol 42 (14) ◽  
pp. 12126-12133 ◽  
Author(s):  
Ning Li ◽  
Weidan Na ◽  
Hua Liu ◽  
Xingguang Su
Keyword(s):  
Quantum Dots ◽  
Gold Nanoparticles ◽  
Fluorescence Detection ◽  
Graphene Quantum Dots ◽  
Inner Filter Effect ◽  
Sulfanilic Acid ◽  
Functionalized Graphene ◽  
Dual Mode ◽  
Mode Detection ◽  
Filter Effect

Visual and fluorescence detection of amifostine based on the inner filter effect of gold nanoparticles on sulfanilic acid functionalized graphene quantum dots.

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