Ultrasensitive detection of nitroexplosive – picric acid via a conjugated polyelectrolyte in aqueous media and solid support

2015 ◽  
Vol 51 (33) ◽  
pp. 7207-7210 ◽  
Author(s):  
Sameer Hussain ◽  
Akhtar Hussain Malik ◽  
Mohammad Adil Afroz ◽  
Parameswar Krishnan Iyer

Cationic polymer PMI detects picric acid at ppt levels via combination of ground state charge transfer, RET and electrostatic interactions. A paper strip test and a contact mode sensing platform using chitosan film confirm the method as simple, portable and cost-effective.

Insects ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 333 ◽  
Author(s):  
Éva Kolics ◽  
Kinga Mátyás ◽  
János Taller ◽  
András Specziár ◽  
Balázs Kolics

Lithium chemicals have been proven to be very effective in eradicating Varroa destructor, the detrimental parasite of the honey bee; however, little is known about the side effects on brood and long term consequences on the colony. Earlier, it was proposed that the action mechanisms of lithium chloride do not include the contact mode. Here, we investigate this question using a paper strip test to demonstrate the concentration-dependent effectiveness of lithium in the contact mode of action, confirming that it is also a contact agent against the Varroa mite. According to our knowledge, this is the first report on the high varroicidal effect of lithium in the contact mode of action. Our findings may open up possibilities for novel ways of treatment (e.g., the use of lithiated strips) in the event that lithium salts become legal for use in apiculture.


2014 ◽  
Vol 6 (21) ◽  
pp. 8464-8468 ◽  
Author(s):  
Xiangcheng Sun ◽  
Xiaoyu Ma ◽  
Challa V. Kumar ◽  
Yu Lei

A novel protein based fluorophore for sensitive, selective and fast detection of picric acid in an aqueous phase due to electron transfer, Förster resonance energy transfer and electrostatic interactions.


2018 ◽  
Vol 9 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Shubhangi J. Mane-Gavade ◽  
Sandip R. Sabale ◽  
Xiao-Ying Yu ◽  
Gurunath H. Nikam ◽  
Bhaskar V. Tamhankar

Introduction: Herein we report the green synthesis and characterization of silverreduced graphene oxide nanocomposites (Ag-rGO) using Acacia nilotica gum for the first time. Experimental: We demonstrate the Hg2+ ions sensing ability of the Ag-rGO nanocomposites form aqueous medium. The developed colorimetric sensor method is simple, fast and selective for the detection of Hg2+ ions in aqueous media in presence of other associated ions. A significant color change was noticed with naked eye upon Hg2+ addition. The color change was not observed for cations including Sr2+, Ni2+, Cd2+, Pb2+, Mg2+, Ca2+, Fe2+, Ba2+ and Mn2+indicating that only Hg2+ shows a strong interaction with Ag-rGO nanocomposites. Under the most suitable condition, the calibration plot (A0-A) against concentration of Hg2+ was linear in the range of 0.1-1.0 ppm with a correlation coefficient (R2) value 0.9998. Results & Conclusion The concentration of Hg2+ was quantitatively determined with the Limit of Detection (LOD) of 0.85 ppm. Also, this method shows excellent selectivity towards Hg2+ over nine other cations tested. Moreover, the method offers a new cost effective, rapid and simple approach for the detection of Hg2+ in water samples.


Cellulose ◽  
2021 ◽  
Author(s):  
Peixin Tang ◽  
Leilah-Marie E. Lockett ◽  
Mengxiao Zhang ◽  
Gang Sun

AbstractA chemical modification of cotton fabrics by 2-diethylaminoethyl chloride (DEAE-Cl) was achieved, and the resulted cotton fabrics demonstrated salt-free dyeing properties with anionic dyes. Nucleophilic property of hydroxyl groups in cotton cellulose was enhanced under alkaline conditions and could react with DEAE-Cl, a chemical possessing both nucleophilic and electrophilic sites. The monolayered DEAE-grafted cotton cellulose could further react with DEAE-Cl to form multiple cationic quaternary ammonium salts (denoted as DEAE@Cotton), which are highly interactive with anionic dye molecules. The strong electrostatic interactions between the DEAE@Cotton and the dyes eliminated the use of inorganic salts in cotton dyeing process. The chemical structure and property of DEAE@Cotton were characterized and compared with untreated cotton. The DEAE@Cotton can be dyed in a salt-free system, and the dye exhaustion was faster than the conventional dyeing method due to the robust electrostatic interactions of the fabrics with anionic dyes. The dyed fabrics demonstrated outstanding color fastness under repeated washing, light exposure, and crocking. The dye adsorption process on DEAE@Cotton follows Langmuir isotherm model (R2 = 0.9667). The mechanism of enhanced dyeability was experimentally proved by treating the fabric with other anionic dyes in a salt-free system, proving the process to be environmentally friendly and cost-effective. Graphic abstract


RSC Advances ◽  
2021 ◽  
Vol 11 (43) ◽  
pp. 26683-26686
Author(s):  
Md. Mahiuddin ◽  
Bungo Ochiai

Lemon juice effectively served as a reducing and capping agent for an easy, cost-effective, and green synthesis of crystalline bismuth nanoparticles (BiNPs) in basic aqueous media.


2017 ◽  
Vol 35 (4) ◽  
pp. 447-456 ◽  
Author(s):  
Zhongyu Ding ◽  
Hongqing Li ◽  
Wanqing Gao ◽  
Yiquan Zhang ◽  
Chunhua Liu ◽  
...  

2012 ◽  
Vol 14 (12) ◽  
pp. 3112-3115 ◽  
Author(s):  
Vandana Bhalla ◽  
Ankush Gupta ◽  
Manoj Kumar
Keyword(s):  

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Ali Q. Alorabi

In this work, magnetized activated Juniperus procera leaves (Fe3O4@AJPL) were successfully prepared via chemical activation of JPL and in situ coprecipitation with Fe3O4. A Fe3O4@AJPL nanocomposite was successfully applied for the elimination of malachite green (MG) dye from aqueous media. The prepared Fe3O4@AJPL adsorbent was characterized by SEM, EDX, TEM, XRD, FTIR, TGA, and BET surface area analyses. The BET surface area and pore size of the Fe3O4@AJPL nanocomposite were found to be 38.44 m2/g and 10.6 nm, respectively. The XRD and FTIR results indicated the formation of a Fe3O4@AJPL nanocomposite. Different parameters, such as pH of the solution (3–8), adsorbent dosage (10–100 mg), temperature (25–45°C), contact time (5-240 min), and initial MG concentrations (20–350 mg/L), for the elimination of the MG dye using Fe3O4@AJPL were optimized and found to be 7, 50 mg, 45°C, 120 min, and 150 mg/L, respectively. The nonlinear isotherm and kinetic studies exhibited a better fitting to second-order kinetic and Langmuir isotherm models, with a maximum monolayer adsorption capacity of 318.3 mg/g at 45°C, which was highly superior to the previously reported magnetic nanocomposite adsorbents. EDX analyses confirmed the presence of nitrogen on the Fe3O4@AJPL surface after MG adsorption. The calculated thermodynamic factors indicated endothermic and spontaneous processes. The desorption of MG dye from Fe3O4@AJPL was performed using a solution of 90% ethanol. Finally, it could be concluded that the designed Fe3O4@AJPL magnetic nanocomposite will be a cost-effective and promising adsorbent for the elimination of MG from aqueous media.


2020 ◽  
Author(s):  
Muhammad Zubair ◽  
Muhammad Qasim Mehmood ◽  
Kashif Riaz ◽  
Amna Zubair ◽  
Ali Arif

<p>This paper presents a compact, cost-effective, and contactless fractal modified EBG-based microwave sensing platform for dielectric characterization of liquids by analyzing the variation in the reflection coefficient of an antenna. The reported design is composed of a triangular-shaped antenna (0.323λ­<sub>o </sub>x 0.323λ­<sub>o</sub>) placed over a 3 x 3 array of Cesaro fractal based EBG plane (0.7λ­<sub>o</sub> x 0.7λ­<sub>o</sub>) operating at 2.45 GHz. A significant enhancement of the E-field in the sensing region has been achieved with the incorporation of Cesaro fractals in the EBG plane which results in increased sensitivity and compactness. To validate its performance, absolute solutions of butan-1-ol, methanol, and water are loaded, and a maximum measured sensitivity of 0.875% and a maximum quality factor of 90.05 is achieved. Moreover, a maximum RMS error in retrieved values of dielectric constant and loss tangent of liquid under test is found to be 1.092% and 0.813%, respectively. Our demonstrated EBG-based sensor has a compact footprint with good precision, affordability, and ease of operation in detecting liquids for microwave sensing applications. </p><p><br></p>


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