scholarly journals A Green, Rapid and Efficient Dual-Sensors for Highly Selective and Sensitive Detection of Cation (Hg2+) and Anion (S2−) Ions Based on CMS/AgNPs Composites

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 113 ◽  
Author(s):  
Yun Xue ◽  
Lina Ma ◽  
Lei Zhang ◽  
Wanting Zhao ◽  
Zichao Li ◽  
...  
Keyword(s):  
Silver Nanoparticle ◽  
High Performance ◽  
Colloidal Solution ◽  
Color Change ◽  
Tap Water ◽  
High Sensitivity ◽  
Carboxymethyl Cellulose Sodium ◽  
Water Based ◽  
Sensitivity And Selectivity ◽  
Toxic Ions

Detection of mercury (Hg2+) and sulfide (S2−), universal and well-known toxic ions, is crucial in monitoring several diseases. How to design and fabricate the high-performance sensor for simultaneously and accurately detecting the Hg2+ and S2− is critical. Herein, we proposed a novel and convenient strategy for optical detection of Hg2+ and S2− by employing a carboxymethyl cellulose sodium/silver nanoparticle (CMS/AgNPs) colloidal solution, in which AgNPs were used as monitor for Hg2+ and S2−, and the CMS was utilized as both the stabilizer and the hydrophilic substrate for AgNPs. Well-identifiable peaks for Hg2+ and S2– were obtained in water based on UV–VIS absorption spectra, the absorbance intensity and/or position of nano-silver vary with the addition of Hg2+ cation and S2– anion, accompanying with color change. Impressively, the optimal AgNPs anchored CMS exhibited a high sensitivity and selectivity toward Hg2+ and S2−, the change in absorbance was linear with the concentration of Hg2+ (0–50 μM) and S2− (15–70 μM), and the lowest limits of detection (LOD) were 1.8 × 10−8 M and 2.4 × 10−7 M, respectively. More importantly, owing to the superior properties in testing Hg2+ and S2−, the fabricated sensor was successfully applied for detection of target ions in lake and tap water samples. All these good results implied that the designed strategy and as-designed samples is promising in detecting cation (Hg2+) and anion (S2−) ions and open up new opportunities for selecting other kinds of ions.

Easy-to-Fabricate K2Pd(SO3)2-Dyed Polyester Fabric with Highly Selective and Fast Response to Carbon Monoxide

2021 ◽  
Vol 21 (8) ◽  
pp. 4400-4405
Author(s):  
Junyeop Lee ◽  
Nam Gon Do ◽  
Dong Hyuk Jeong ◽  
Sae-Wan Kim ◽  
Maeum Han ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Color Change ◽  
High Sensitivity ◽  
Cost Effective ◽  
Fast Response ◽  
Polyester Fabric ◽  
High Porosity ◽  
Sensing Material ◽  
Sensitivity And Selectivity ◽  
And Performance

Carbon monoxide (CO) is an odorless, colorless, tasteless, extremely flammable, and highly toxic gas. It is produced when there is insufficient oxygen supply during the combustion of carbon to produce carbon dioxide (CO2). CO is produced from operating engines, stoves, or furnaces. CO poisoning occurs when CO accumulates in the bloodstream and can result in severe tissue damage or even death. Many types of CO sensors have been reported, including electrochemical, semiconductor metal-oxide, catalytic combustion, thermal conductivity, and infrared absorption-type for the detection of CO. However, despite their excellent selectivity and sensitivity, issues such as complexity, power consumption, and calibration limit their applications. In this study, a fabricbased colorimetric CO sensor is proposed to address these issues. Potassium disulfitopalladate (II) (K2Pd(SO3)2) is dyed on a polyester fabric as a sensing material for selective CO detection. The sensing characteristics and performance are investigated using optical instruments such as RGB sensor and spectrometer. The sensor shows immediate color change when exposed to CO at a concentration that is even lower than 20 ppm before 2 min. The fast response time of the sensor is attributed to its high porosity to react with CO. This easy-to-fabricate and cost-effective sensor can detect and prevent the leakage of CO simultaneously with high sensitivity and selectivity toward CO.

A confined carbon dot-based self-calibrated fluorescence probe for visible and high-sensitivity moisture readouts

2021 ◽  
Author(s):  
Zhong-Zheng Ding ◽  
Guang-Song Zheng ◽  
Qing Lou ◽  
Jiang-Fan Han ◽  
Meng-Yuan Wu ◽  
...  
Keyword(s):  
High Performance ◽  
Potential Role ◽  
Fluorescence Probe ◽  
Color Change ◽  
High Sensitivity ◽  
Confinement Effect ◽  
Detection Range ◽  
Fluorescence Color ◽  
Highly Sensitive ◽  
New Type

Abstract Excellent luminescent materials are essential for high-performance fluorescent nanosensors. Here, a new-type self-calibrated humidity sensor has been established through monitoring the fluorescent color change of carbon dots (CDs) confined in sodium hydroxide (CDs@NaOH). The CDs are prepared by a facile and rapid microwave assisted heating method using citric acid, urea, and NaOH as precursors. The confinement effect from NaOH has reduced the nonradiative transition and suppressed the aggregation-induced quenching of the CDs in solid. Compared with other sensors based on CD fluorescent visualization, the sensor has good linearity and wide humidity detection range from 6.9% to 95.4%. With the increased relative humidity, the fluorescence color of the sensor change from green to blue. The proposed sensing mechanism is due to the breaking and reforming of hydrogen bonds and proton transfer occurring at the CD-NaOH matrix interfaces. This finding suggests a potential role for the spatial confinement effect and may provide an avenue for developing highly sensitive humidity readouts.

scholarly journals Chromatographic Methods for the Determination of Aminexil, Pyridoxine, and Niacinamide in a Novel Cosmetic Hair Preparation

2020 ◽  
Vol 103 (4) ◽  
pp. 1167-1172
Author(s):  
Mamdouh R Rezk ◽  
Hebatallah M Essam ◽  
Enas A Amer ◽  
Dina M S Youssif
Keyword(s):  
High Performance ◽  
High Sensitivity ◽  
Ammonia Solution ◽  
Hplc Method ◽  
The Novel ◽  
Chromatographic Methods ◽  
Ich Guidelines ◽  
Sensitivity And Selectivity ◽  
Keratin Fibers

Abstract Background Aminexil, a new compound patented by L’Oreal, has a stimulating effect on human keratin fibers. Pyridoxine HCl and niacinamide are added to boost the hair tonic effect of aminexil. Objective Two novel chromatographic methods were developed for the determination of aminexil (AX), niacinamide (NA) and pyridoxine HCl (PD) in the novel hair tonic preparation. Methods The developed methods were high-performance liquid chromatography (HPLC) and thin layer chromatography (TLC) with densitometric determination. Different experimental parameters were investigated and optimized to achieve complete baseline separation and well resolved peaks. The RP-HPLC separation was achieved using a Thermoscientific BDS hypersil C18 (250 × 4.6 mm, 5 µm) column using 0.005 M hexane sulfonic acid: methanol (80: 20, v/v) as a mobile phase. For the TLC method, the three analytes were partitioned between propanol: toluene: ammonia solution (40:60:2, v/v/v) and fluorescent silica plates. The two methods were validated in compliance with International Conference on Harmonization (ICH) guidelines. The obtained data were statistically analyzed to confirm the existing results. The developed methods were successfully applied for determination of the studied drugs in pure forms and in the cosmetic preparation. Results For the HPLC method, the RSDs of AX, NA and PD were 0.70, 0.88 and 1.17 respectively. For the TLC method, the RSDs of AX, NA and PD were 1.06, 1.37 and 0.73 respectively. Conclusions The proposed chromatographic methods showed high sensitivity and selectivity for the three compounds under analysis in the laboratory prepared mixture and in the hair tonic preparation. Highlights Aminexil, Pyridoxine, Niacinamide, HPLC. The present work offers two reproducible, accurate, validated, time and cost saving alternatives for the quantitative and qualitative determination of medicated hair preparation.

Non-enzymatic colorimetric sensor strip based on melamine-functionalized gold nanoparticles assembled on polyamide nanofiber membranes for the detection of metronidazole

2019 ◽  
Vol 11 (29) ◽  
pp. 3706-3713 ◽  
Author(s):  
Mohammed Awad Abedalwafa ◽  
Yan Li ◽  
Chunfang Ni ◽  
Gang Yang ◽  
Lu Wang
Keyword(s):  
Gold Nanoparticles ◽  
Color Change ◽  
High Sensitivity ◽  
Colorimetric Sensor ◽  
Eye Detection ◽  
Naked Eye ◽  
Functionalized Gold Nanoparticles ◽  
Sensitivity And Selectivity ◽  
Nanofiber Membranes ◽  
Naked Eye Detection

Non-enzymatic colorimetric sensor strip for detection of metronidazole (MTZ) was designed and constructed, with high sensitivity and selectivity. Which can be used for naked-eye detection of MTZ with a visible color change from pink to purple.

scholarly journals A Naphthalimide-Benzothiazole Conjugate as Colorimetric and Fluorescent Sensor for Selective Trinitrophenol Detection

Chemosensors ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 38 ◽  
Author(s):  
Pramod D. Jawale Patil ◽  
Rajita D. Ingle ◽  
Sopan M. Wagalgave ◽  
Rajesh S. Bhosale ◽  
Sidhanath V. Bhosale ◽  
...  
Keyword(s):  
Color Change ◽  
Limit Of Detection ◽  
Fluorescent Sensor ◽  
Uv Light ◽  
High Sensitivity ◽  
Design And Synthesis ◽  
Bonding Interaction ◽  
Sensitivity And Selectivity ◽  
Donor Acceptor ◽  
Aromatic Nitro

Although chemical structural modification of naphthalimides is widely employed for the purpose of sensing explosives, the effects of such modification have been little explored. Herein, we report the design and synthesis of a new naphthalimide-benzothiazole conjugate (1) and its ability to sense various nitrophenols by means of its colorimetric and fluorescent characteristics. Under long-range UV light (365 nm), 1 displayed a color change of its solution from bluish to colorless only upon addition of 2,4,6-trinitrophenol (TNP). Photoluminescence spectroscopy showed quantitative fluorescence quenching by TNP of the emission peaks of 1 at 398 nm and 418 nm due to donor–acceptor electron transfer. The interaction of 1 with TNP was via a cooperative, non-covalent hydrogen-bonding interaction. Receptor 1 exhibited high sensitivity and selectivity towards TNP over various aromatic nitro analytes. The binding constant (K) and Stern–Volmer constant (Ksv) between 1 and TNP were found to be 5.332 × 10−5 M and 2.271 × 106 M−1, respectively. Furthermore, the limit of detection was calculated and found to be as low as 1.613 × 10−10 M.

scholarly journals Isatin as a simple, highly selective and sensitive colorimetric sensor for fluoride anion

2020 ◽  
Vol 26 (1) ◽  
pp. 14-19 ◽  
Author(s):  
Azeem Haider ◽  
Mukhtiar Ahmed ◽  
Muhammad Faisal ◽  
Muhammad Moazzam Naseer
Keyword(s):  
Color Change ◽  
Colour Change ◽  
High Sensitivity ◽  
Fluoride Anion ◽  
Base Interaction ◽  
Spectral Changes ◽  
Vis Spectroscopy ◽  
Sensitivity And Selectivity ◽  
Sensitive Sensor ◽  
Acid Base Interaction

AbstractHerein, we report the fluoride anion sensing properties of a commercially available and inexpensive organic compound, isatin, which is found to be a highly selective and sensitive sensor. In naked-eye experiments, by addition of fluoride anions, isatin shows a dramatic color change from pale yellow to violet at room temperature, while the addition of other anions, i.e. $\mathrm{Cl}^-,$$\mathrm{Br}^-,\mathrm I^-,\mathrm{ClO}_4^-,{\mathrm H}_2\mathrm{PO}_4^-\,\mathrm{and}\,\mathrm{PF}_6^-,$did not induce any colour change. Additionally, recognition and titration studies have also been done through UV/Vis spectroscopy. Isatin displayed a new absorption band at 533 nm after the addition of fluoride anions, which is presumably due to acid-base interaction between isatin and fluoride anions, while other anions did not trigger noticeable spectral changes. The detection limit was observed to be 0.367 ppm. DFT calculations were also performed to further explain the behavior of receptor 1 towards the Fˉ anion. Owing to high sensitivity and selectivity, isatin can be useful in the detection of biologically or environmentally important fluoride anions at very low concentration.

scholarly journals Styrene and Azo-Styrene Based Colorimetric Sensors for Highly Selective Detection of Cyanide

2017 ◽  
Vol 17 (2) ◽  
pp. 238
Author(s):  
Agustina Eka Prestiani ◽  
Bambang Purwono
Keyword(s):  
Color Change ◽  
Knoevenagel Condensation ◽  
Condensation Reaction ◽  
Aqueous Media ◽  
Colour Change ◽  
High Sensitivity ◽  
Colorimetric Sensing ◽  
Sensitivity And Selectivity ◽  
One Step ◽  
Knoevenagel Condensation Reaction

A novel styrene (1) and azo-styrene (2) based chemosensor from vanillin has been successfully synthesized. Sensor 1 was obtained by one step Knoevenagel condensation of Ultrasound method and sensor 2 by coupling diazo and Knoevenagel condensation reaction. Both of sensors showed high sensitivity and selectivity to detect CN- in aqueous media, even the presence of other anions, such as F-, Cl-, Br-, I-, CO32-, SO42-, H2PO4-, and AcO-. Colorimetric sensing of sensor 1 is inclined to be deprotonating of sensor binding site in the presence of cyanide and consequently improve the selectivity and sensitivity in sensing cyanide which displayed color change of sensor from yellowness to red-purple and then purple in 1 min. Sensor 2 exhibited chemodosimeter phenomenon which is caused by the nucleophilic addition of cyanide with a colour change from green to greenish-blue. The results enable to do an anion detection by a naked eye.

scholarly journals Grafting of Silica Particles with Linoleic Acid via Modified Stober’s Method for Preconcenrtration of Pesticides in Drinking Water

2018 ◽  
Vol 778 ◽  
pp. 316-324
Author(s):  
Sadia Atta ◽  
Mehreen Fatima ◽  
Atif Islam ◽  
Nafisa Gull ◽  
Misbah Sultan
Keyword(s):  
Drinking Water ◽  
Linoleic Acid ◽  
Organochlorine Pesticides ◽  
High Performance ◽  
Solid Phase ◽  
High Sensitivity ◽  
Reverse Phase ◽  
Carcinogenic Activity ◽  
Ultraviolet Detector ◽  
Sensitivity And Selectivity

The extensive use of pesticides in agricultur has raised toxicity level in environment because of their mutagenic and carcinogenic activity. A sensitive technique is needed to develop for the detection of pesticides to get high sensitivity and selectivity in complex matrices. Modified Stober‘s method was used for the synthesis of pure SiO2 particles and grafted by linoleic acid. Grafted SiO2 were examined for its capability as a sorbent for removal and preconcentration of four organochlorine pesticides i.e. endrin, dieldrin, aldrin and DDT. The particles of SiO2 undergo hydrophobic interaction with linoleic acid by grafting. Both pure SiO2 and linoleic acid grafted SiO2 particles were characterized by SEM, FTIR and XRD. FTIR confirmed the grafting of SiO2 with linoleic acid. XRD and SEM results showed monodispersed and spherical SiO2 particles. The evaluation of grafted SiO2 was carried out by spiking organochlorine pesticides in drinking water. The grafted SiO2 particles could be used as a sorbent in solid phase extraction followed by high performance liquid chromatography with reverse phase C18 column with aqueous acetonitrile as a mobile phase with ultraviolet detector at 224 nm. The percent recoveries for aldrin, dieldin, endrin and DDT were 81, 52, 60 and 91%, respectively.

scholarly journals Fabrication, Flow Control, and Applications of Microfluidic Paper-Based Analytical Devices

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2869 ◽  
Author(s):  
Lim ◽  
Jafry ◽  
Lee
Keyword(s):  
Fluid Flow ◽  
High Performance ◽  
Point Of Care ◽  
High Sensitivity ◽  
Theoretical Background ◽  
Detection Techniques ◽  
Advantages And Disadvantages ◽  
Sensitivity And Selectivity ◽  
Paper Based Microfluidics ◽  
Flow Manipulation

Paper-based microfluidic devices have advanced significantly in recent years as they are affordable, automated with capillary action, portable, and biodegradable diagnostic platforms for a variety of health, environmental, and food quality applications. In terms of commercialization, however, paper-based microfluidics still have to overcome significant challenges to become an authentic point-of-care testing format with the advanced capabilities of analyte purification, multiplex analysis, quantification, and detection with high sensitivity and selectivity. Moreover, fluid flow manipulation for multistep integration, which involves valving and flow velocity control, is also a critical parameter to achieve high-performance devices. Considering these limitations, the aim of this review is to (i) comprehensively analyze the fabrication techniques of microfluidic paper-based analytical devices, (ii) provide a theoretical background and various methods for fluid flow manipulation, and iii) highlight the recent detection techniques developed for various applications, including their advantages and disadvantages.

A dimethyl methylphonate sensor based on HFIPPH modified SWCNTs

2022 ◽  
Author(s):  
Haiyang Wu ◽  
Yubin Yuan ◽  
Qiang Wu ◽  
Xiangrui Bu ◽  
Long Hu ◽  
...  
Keyword(s):  
Gas Sensor ◽  
Self Assembly ◽  
High Performance ◽  
Gas Sensing ◽  
Detection System ◽  
High Sensitivity ◽  
Assembly Method ◽  
Sensitivity And Selectivity ◽  
Effect Transistor ◽  
Walled Carbon Nanotubes

Abstract In order to meet the requirements of ultra-fast real-time monitoring of sarin simulator with high sensitivity and selectivity, it is of great significance to develop high performance dimethyl methylphonate (DMMP) sensor. Herein, we proposed a DMMP sensor based on p-hexafluoroisopropanol phenyl (HFIPPH) modified self-assembled single-walled carbon nanotubes (SWCNTs) with field effect transistor (FET) structure. The self-assembly method provides a 4 nanometres thick and micron sized SWCNT channel, with high selectivity to DMMP. The proposed SWCNTs-HFIPPH based sensor exhibits remarkably higher response to DMMP than bare SWCNT based gas sensor within only few seconds. The gas sensing response of SWCNTs-HFIPPH based sensor for 1ppm DMMP is 18.2%, and the response time is about 10 seconds. What's more, the gas sensor we proposed here shows excellent selectivity and reproducibility, and the limitation of detection is as low as ppb level. The proposed method lays the foundation for miniaturization and integration of DMMP sensors, expecting to develop detection system for practical sarin sensing application.

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