scholarly journals Carbon dots functionalized papers for high-throughput sensing of 4-chloroethcathinone and its analogues in crime sites

2019 ◽  
Vol 6 (9) ◽  
pp. 191017 ◽  
Author(s):  
Yao-Te Yen ◽  
Yu-Syuan Lin ◽  
Ting-Yueh Chen ◽  
San-Chong Chyueh ◽  
Huan-Tsung Chang
Keyword(s):  
Aqueous Solution ◽  
Carbon Dots ◽  
Low Cost ◽  
New Psychoactive Substances ◽  
Hydrothermal Route ◽  
Photoluminescence Quenching ◽  
Sensing System ◽  
Uv Lamp ◽  
Abused Drugs ◽  
Solid Ink Printing

Sensitive and selective assays are demanded for quantitation of new psychoactive substances such as 4-chloroethcathinone that is a π-conjugated keto compound. Carbon dots (C-dots) prepared from L-arginine through a hydrothermal route have been used for quantitation of 4-chloroethcathinone in aqueous solution and on C-dot-functionalized papers (CDFPs). To prepare CDFPs, chromatography papers, each with a pattern of 8 × 12 circles (wells), are first fabricated through a solid-ink printing method and then the C-dots are coated into the wells. π-Conjugated keto or ester compounds induce photoluminescence quenching of C-dots through an electron transfer process. At pH 7.0, the CDFPs allow screening of abused drugs such as cocaine, heroin and cathinones. Because of poor solubility of heroin and cocaine at pH 11.0, the C-dot probe is selective for cathinones. The C-dots in aqueous solution and CDFPs at pH 11.0 allow quantitation of 4-chloroethcathinone down to 1.73 mM and 0.14 mM, respectively. Our sensing system consisting of a portable UV-lamp, a smartphone and a low-cost CDFP has been used to detect cathinones, cocaine and heroin at pH 7.0, showing its potential for screening of these drugs in crime sites.

scholarly journals A Multi-Catalytic Sensing for Hydrogen Peroxide, Glucose, and Organophosphorus Pesticides Based on Carbon Dots

2021 ◽  
Vol 9 ◽  
Author(s):  
Ping Li ◽  
Xiang-Ying Sun ◽  
Jiang-Shan Shen
Keyword(s):  
Catalytic Reaction ◽  
Carbon Dots ◽  
Limit Of Detection ◽  
Organophosphorus Pesticides ◽  
Choline Oxidase ◽  
Hydrothermal Route ◽  
One Pot ◽  
Catalytic Systems ◽  
Sensing System ◽  
Fruit Samples

In this work, a facile one-pot hydrothermal route was employed to synthesize a series of fluorescent carbon dots (CDs) by using 20 natural amino acids, respectively, as the starting materials. It was found that the CDs synthesized using phenylalanine could possess the intrinsic peroxidase-like activity that could effectively catalyze a traditional peroxidase substrate like 3, 3’, 5, 5’- tetramethylbenzidine (TMB) in the presence of H2O2 to produce a blue solution; thereby, a catalytic sensing system for H2O2 has been developed. On the basis of this catalytic reaction, together with the fact that glucose oxidase (GOx) can catalyze the hydrolysis of glucose to generate H2O2, a sensitive catalytic sensing system for glucose could be further established. Furthermore, based on this catalytic reaction, taken together with the two enzymatic catalytic systems of acetylcholinesterase (AChE) and choline oxidase (CHO), a highly sensitive multi-catalytic sensing system could be successfully developed for organophosphorus (OPs) pesticides such as dimethoate, DDVP, and parathion-methyl. Limit of detections (LODs) of H2O2 and glucose were estimated to be 6.5 and 0.84 μM, respectively. The limit of detection of the sub-nM level could be obtained for tested dimethoate, DDVP, and parathion-methyl OPs pesticides. The established sensing systems can exhibit good practical application performance in serum and several fruit samples.

Photo-degradation of monoazo dye blue 13 using advanced oxidation process

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Aqueous Solution ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
High Energy ◽  
Uv Exposure ◽  
H2o2 Concentration ◽  
Oxidizing Agent ◽  
Photo Degradation ◽  
High Energy Radiation ◽  
Uv Lamp

The high energy radiation overcome the bonding of solute in a solution and H2O2 acts as an oxidizing agent and generates a free radical in the solution which results in photo-degradation by converting the solute in to simple form and resultantly, colored substance under the effect of photo-degradation becomes colorless. The photo-degradation of monoazo dye Blue 13 in an aqueous solution was investigated using a laboratory scale UV lamp in the presence of H2O2 and for maximum degradation of dye, the independent parameter UV power, UV exposure time, pH and H2O2 concentration were optimized. It was found that neither UV in the presence of H2O2 is able to degrade Blue 13 under optimum condition. The results revealed that the use of both UV and H2O2 have pronounced effect on the discoloration of dyes which could be used for management of textile effluents contain waste dyes.

scholarly journals Spent Coffee Ground as Low-Cost Adsorbent for Congo Red Dye Removal from Aqueous Solution

2021 ◽  
Vol 765 (1) ◽  
pp. 012089
Author(s):  
R Taufik ◽  
M Mohamad ◽  
R Wannahari ◽  
N F Shoparwe ◽  
WHW Osman ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Congo Red ◽  
Dye Removal ◽  
Low Cost ◽  
Congo Red Dye ◽  
Spent Coffee Ground ◽  
Coffee Ground ◽  
Red Dye

scholarly journals Towards Iron-Titanium Oxide Nanostructures from Ecuadorian Black Mineral Sands

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 122
Author(s):  
Karina J. Lagos ◽  
Bojan A. Marinkovic ◽  
Alexis Debut ◽  
Karla Vizuete ◽  
Víctor H. Guerrero ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Titanium Oxide ◽  
Low Cost ◽  
Mineral Resources ◽  
Added Value ◽  
Secondary Phases ◽  
Hydrothermal Route ◽  
Oxide Nanostructures ◽  
Transmission Electron ◽  
Pre Treatment

Ecuadorian black mineral sands were used as starting material for the production of iron-titanium oxide nanostructures. For this purpose, two types of mineral processing were carried out, one incorporating a pre-treatment before conducting an alkaline hydrothermal synthesis (NaOH 10 M at 180 °C for 72 h), and the other prescinding this first step. Nanosheet-assembled flowers and nanoparticle agglomerates were obtained from the procedure including the pre-treatment. Conversely, nanobelts and plate-like particles were prepared by the single hydrothermal route. The nanoscale features of the product morphologies were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. The ilmenite and hematite molar fractions, within the ilmenite-hematite solid solution, in the as-synthetized samples were estimated by Brown’s approach using the computed values of unit-cell volumes from Le Bail adjustments of X-ray powder diffraction (XRPD) patterns. The resulting materials were mainly composed of Fe-rich ilmenite-hematite solid solutions (hematite molar contents ≥0.6). Secondary phases, which possibly belong to lepidocrocite-like or corrugated titanate structures, were also identified. The current study demonstrated the feasibility of employing Ecuadorian mineral resources as low-cost precursors to synthesize high-added-value nanostructures with promising applications in several fields.

Low cost earthworm manure-derived carbon material for the adsorption of Cu 2+ from aqueous solution: Impact of pyrolysis temperature

2017 ◽  
Vol 98 ◽  
pp. 189-195 ◽  
Author(s):  
Bin Zhou ◽  
Zhanghong Wang ◽  
Dekui Shen ◽  
Fei Shen ◽  
Chunfei Wu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Carbon Material ◽  
Pyrolysis Temperature ◽  
Low Cost
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