scholarly journals High-Performance Gas Sensor of Polyaniline/Carbon Nanotube Composites Promoted by Interface Engineering

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 149 ◽  
Author(s):  
Weiyu Zhang ◽  
Shuai Cao ◽  
Zhaofeng Wu ◽  
Min Zhang ◽  
Yali Cao ◽  
...  
Keyword(s):  
High Performance ◽  
Structural Changes ◽  
Gas Sensing ◽  
Response Times ◽  
Limit Of Detection ◽  
Hierarchical Structures ◽  
Cost Effective ◽  
One Dimensional ◽  
P Type ◽  
Sensing Performance

Inspired by the enhanced gas-sensing performance by the one-dimensional hierarchical structure, one-dimensional hierarchical polyaniline/multi-walled carbon nanotubes (PANI/CNT) fibers were prepared. Interestingly, the simple heating changed the sensing characteristics of PANI from p-type to n-type and n-type PANI and p-type CNTs form p–n hetero junctions at the core–shell interface of hierarchical PANI/CNT composites. The p-type PANI/CNT (p-PANI/CNT) and n-type PANI/CNT (n-PANI/CNT) performed the higher sensitivity to NO2 and NH3, respectively. The response times of p-PANI/CNT and n-PANI/CNT to 50 ppm of NO2 and NH3 are only 5.2 and 1.8 s, respectively, showing the real-time response. The estimated limit of detection for NO2 and NH3 is as low as to 16.7 and 6.4 ppb, respectively. After three months, the responses of p-PANI/CNT and n-PANI/CNT decreased by 19.1% and 11.3%, respectively. It was found that one-dimensional hierarchical structures and the deeper charge depletion layer enhanced by structural changes of PANI contributed to the sensitive and fast responses to NH3 and NO2. The formation process of the hierarchical PANI/CNT fibers, p–n transition, and the enhanced gas-sensing performance were systematically analyzed. This work also predicts the development prospects of cost-effective, high-performance PANI/CNT-based sensors.

P-type Co3O4 nanoarrays decorated on the surface of n-type flower-like WO3 nanosheets for high-performance gas sensing

2019 ◽  
Vol 288 ◽  
pp. 104-112 ◽  
Author(s):  
Yanghai Gui ◽  
Lele Yang ◽  
Kuan Tian ◽  
Hongzhong Zhang ◽  
Shaoming Fang
Keyword(s):  
High Performance ◽  
Gas Sensing ◽  
P Type ◽  
Co3o4 Nanoarrays

scholarly journals Enhancing room-temperature NO2 gas sensing performance based on a metal phthalocyanine/graphene quantum dot hybrid material

RSC Advances ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 5618-5628
Author(s):  
Wenkai Jiang ◽  
Xinwei Chen ◽  
Tao Wang ◽  
Bolong Li ◽  
Min Zeng ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Gas Sensor ◽  
Hybrid Material ◽  
High Performance ◽  
Room Temperature ◽  
Gas Sensing ◽  
Metal Phthalocyanine ◽  
Graphene Quantum Dot ◽  
Sensing Performance

A high performance gas sensor based on a metal phthalocyanine/graphene quantum dot hybrid material was fabricated for NO2 detection at room-temperature.

Stability Indicating HPTLC Method for Simultaneous Determination of Amlodipine Besylate and Lisinopril in Combined Dose Tablet Formulation

2021 ◽  
pp. 6250-6256
Author(s):  
Sagar B. Wankhede ◽  
Deepak S. Khobragade ◽  
Sukeshini B. Lote ◽  
S. Patil
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Degradation Products ◽  
Cost Effective ◽  
Tablet Formulation ◽  
Simultaneous Estimation ◽  
Amlodipine Besylate ◽  
Stability Indicating ◽  
Limit Of Quantitation ◽  
Dose Tablet

A combined dose tablet formulation containing Amlodipine besylate and Lisinopril is used for the treatment of essential hypertension. The present study reports development and validation of stability indicating high performance thin layer chromatographic method for simultaneous estimation of these drugs in combined dose tablet formulation. The two drugs were satisfactorily resolved on aluminum plates precoated with silica gel 60F254 using n-butanol : methanol: ammonia (4:4:1 v/v/v) as mobile phase. The Rf value for lisinopril and amlodipine besylate were 0.27±0.02 and 0.62±0.02, respectively. Densitometric evaluation of the separated bands was performed at 215nm. The calibration curves for lisinopril and amlodipine besylate were found to be linear in the concentration range of 1000-6000ng/band. The method was validated as per ICH guidelines for accuracy, precision, robustness, specificity, limit of detection and limit of quantitation. Statistical analysis proves that the method is suitable for simultaneous analysis of Lisinopril and Amlodipine besylate in pharmaceutical formulation without any interference from the excipients/degradant. The developed method offers several advantages such as sensitive, rapid, cost effective and less time consuming as compared to the reported methods. As the method could effectively separate the drugs from its degradation products, it can be employed as a stability indicating method.

Simple post-synthesis of mesoporous p-type Co3O4 nanochains for enhanced H2S gas sensing performance

2018 ◽  
Vol 270 ◽  
pp. 158-166 ◽  
Author(s):  
Pham Long Quang ◽  
Nguyen Duc Cuong ◽  
Tran Thai Hoa ◽  
Hoang Thai Long ◽  
Chu Manh Hung ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Post Synthesis ◽  
P Type ◽  
Sensing Performance

Vortex-Assisted Dispersive Liquid–Liquid Microextraction Coupled with Deproteinization for Determination of Nateglinide in Human Plasma Using HPLC/UV

2020 ◽  
Author(s):  
Mohamed A Hammad ◽  
Amira H Kamal ◽  
Reham E Kannouma ◽  
Fotouh R Mansour
Keyword(s):  
Human Plasma ◽  
High Performance ◽  
Limit Of Detection ◽  
Signal To Noise Ratio ◽  
Cost Effective ◽  
Salt Addition ◽  
Relative Standard ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

Abstract A validated method for preconcentration and determination of nateglinide in plasma was developed using vortex-assisted dispersive liquid–liquid microextraction. Different variables that affect extraction efficiency were studied and optimized, including type and volume of extractant, type and volume of disperser, pH of diluent, salt addition effect, centrifugation and vortex time. Nateglinide was extracted using 30 μL of 1-octanol as an extractant and 200 μL of methanol as a disperser. The enrichment factor reached 330 under the optimum conditions. High-performance liquid chromatography/ultraviolet was used for detection using phosphate buffer (pH 2.5, 10 mM): acetonitrile (45:55, v/v) as a mobile phase at a flow rate of 1 mL/min. The method was linear over the range of 50–20,000 ng/mL with a limit of detection of 15 ng/mL (signal-to-noise ratio = 3). Intra- and inter-day precision had %relative standard deviation <6% (n = 3) and the %recoveries were found to be between 102.5 and 105.9%. The proposed method is simple, sensitive, eco-friendly, cost-effective and powerful for microextraction of nateglinide from human plasma samples.

scholarly journals High Performance Acetylene Sensor with Heterostructure Based on WO3 Nanolamellae/Reduced Graphene Oxide (rGO) Nanosheets Operating at Low Temperature

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 909 ◽  
Author(s):  
Zikai Jiang ◽  
Weigen Chen ◽  
Lingfeng Jin ◽  
Fang Cui ◽  
Zihao Song ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Gas Sensor ◽  
High Performance ◽  
Gas Sensing ◽  
Hybrid Nanocomposites ◽  
Transformer Oil ◽  
X Ray ◽  
Reduced Graphene ◽  
Sensing Performance

The development of functionalized metal oxide/reduced graphene oxide (rGO) hybrid nanocomposites concerning power equipment failure diagnosis is one of the most recent topics. In this work, WO3 nanolamellae/reduced graphene oxide (rGO) nanocomposites with different contents of GO (0.5 wt %, 1 wt %, 2 wt %, 4 wt %) were synthesized via controlled hydrothermal method. X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetric analyses-derivative thermogravimetric analysis-differential scanning calorimetry (TG-DTG-DSC), BET, and photoluminescence (PL) spectroscopy were utilized to investigate morphological characterizations of prepared gas sensing materials and indicated that high quality WO3 nanolamellae were widely distributed among graphene sheets. Experimental ceramic planar gas sensors composing of interdigitated alumina substrates, Au electrodes, and RuO2 heating layer were coated with WO3 nanolamellae/reduced graphene oxide (rGO) films by spin-coating technique and then tested for gas sensing towards multi-concentrations of acetylene (C2H2) gases in a carrier gas with operating temperature ranging from 50 °C to 400 °C. Among four contents of prepared samples, sensing materials with 1 wt % GO nanocomposite exhibited the best C2H2 sensing performance with lower optimal working temperature (150 °C), higher sensor response (15.0 toward 50 ppm), faster response-recovery time (52 s and 27 s), lower detection limitation (1.3 ppm), long-term stability, and excellent repeatability. The gas sensing mechanism for enhanced sensing performance of nanocomposite is possibly attributed to the formation of p-n heterojunction and the active interaction between WO3 nanolamellae and rGO sheets. Besides, the introduction of rGO nanosheets leads to the impurity of synthesized materials, which creates more defects and promotes larger specific area for gas adsorption, outstanding conductivity, and faster carrier transport. The superior gas sensing properties of WO3/rGO based gas sensor may contribute to the development of a high-performance ppm-level gas sensor for the online monitoring of dissolved C2H2 gas in large-scale transformer oil.

scholarly journals Multicomponent Metal Oxide Nanostructures: Fabrication and Study of Core Issues to Improve Gas Sensing Performance

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 970
Author(s):  
Vardan Galstyan ◽  
Andrea Ponzoni ◽  
Iskandar Kholmanov ◽  
Marta M. Natile ◽  
Antonella Glisenti ◽  
...  
Keyword(s):  
Chemical Sensors ◽  
Gas Sensing ◽  
Cost Effective ◽  
Sensing Properties ◽  
Oxide Nanostructures ◽  
Porous Titania ◽  
Metal Oxide Nanostructures ◽  
Potential Applications ◽  
Core Issues ◽  
Sensing Performance

We have obtained and studied the sensing properties of porous titania-based nanostructures. The materials have been prepared using cost-effective techniques. The morphological and structural analyses of the prepared materials have been performed. The sensing properties of the samples have been studied towards carbon monoxide. The obtained results demonstrate that the prepared structures are promising for the potential applications in the area of chemical sensors for the environmental monitoring.

scholarly journals Incorporating N Atoms into SnO2 Nanostructure as an Approach to Enhance Gas Sensing Property for Acetone

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 445 ◽  
Author(s):  
Xiangfeng Guan ◽  
Yongjing Wang ◽  
Peihui Luo ◽  
Yunlong Yu ◽  
Dagui Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gas Sensor ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Gas Sensing ◽  
Diffuse Reflectance Spectroscopy ◽  
Limit Of Detection ◽  
Low Cost ◽  
X Ray ◽  
Sno2 Nanostructure

The development of high-performance acetone gas sensor is of great significance for environmental protection and personal safety. SnO2 has been intensively applied in chemical sensing areas, because of its low cost, high mobility of electrons, and good chemical stability. Herein, we incorporated nitrogen atoms into the SnO2 nanostructure by simple solvothermal and subsequent calcination to improve gas sensing property for acetone. The crystallization, morphology, element composition, and microstructure of as-prepared products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Electron paramagnetic resonance (EPR), Raman spectroscopy, UV–visible diffuse reflectance spectroscopy (UV–vis DRS), and the Brunauer–Emmett–Teller (BET) method. It has been found that N-incorporating resulted in decreased crystallite size, reduced band-gap width, increased surface oxygen vacancies, enlarged surface area, and narrowed pore size distribution. When evaluated as gas sensor, nitrogen-incorporated SnO2 nanostructure exhibited excellent sensitivity for acetone gas at the optimal operating temperature of 300 °C with high sensor response (Rair/Rgas − 1 = 357) and low limit of detection (7 ppb). The nitrogen-incorporated SnO2 gas sensor shows a good selectivity to acetone in the interfering gases of benzene, toluene, ethylbenzene, hydrogen, and methane. Furthermore, the possible gas-sensing mechanism of N-incorporated SnO2 toward acetone has been carefully discussed.

METHOD DEVELOPMENT AND VALIDATION OF OLANZAPINE IN PURE AND PHARMACEUTICAL DOSAGE FORM BY RP-HPLC METHOD

INDIAN DRUGS ◽  
2013 ◽  
Vol 50 (02) ◽  
pp. 20-26
Author(s):  
V.S Mastiholimath ◽  
◽  
P.M. Dandagi ◽  
A.P. Gadad ◽  
N.V Murali Krishna ◽  
...  
Keyword(s):  
High Performance ◽  
Dosage Form ◽  
Method Development ◽  
Limit Of Detection ◽  
Cost Effective ◽  
Hplc Method ◽  
Chromatography Method ◽  
Pharmaceutical Dosage Form ◽  
Relative Standard ◽  
Ammonium Hydrogen

A simple and reliable reverse phase high-performance liquid chromatography method was developed and validated for Olanzapine in pure and pharmaceutical dosage form. The method was developed on BDS Hypersil C18, (150 mm x 4.6 mm, 3μm) with a mobile phase of 0.01M tetra butyl ammonium hydrogen sulphate : methanol (80:20 v/v). The effluent was monitored by SPD-M20A, prominence UV-VIS detector at 234 nm. Calibration curve was linear over the concentration range of 10 –60μg/ml For interday and intraday precision % relative standard deviation values were found to be 0.18% and 0.24% respectively. Recovery of olanzapine was found to be in the range of 99.93 -100.00%. The limit of detection (LOD) and quantitation (LOQ) were 0.39275 and 1.1901μg/ml, respectively. The retention time and run time was very short; hence it is cost effective, making it more economical and rapid. Also this method can be used for the analysis of large number of samples.

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