scholarly journals Механизм люминесцентного хемосенсорного отклика в хелатах европия(III)

2022 ◽  
Vol 130 (3) ◽  
pp. 428
Author(s):  
Н.В. Петроченкова ◽  
Т.Б. Емелина ◽  
А.Г. Мирочник
Keyword(s):  
Limit Of Detection ◽  
High Sensitivity ◽  
Linear Increase ◽  
Structural Fragment ◽  
Chemical Modeling ◽  
Safety Control ◽  
Quenching Effect ◽  
Quantitative Measurements ◽  
Sensitivity And Selectivity ◽  
Acrylic Acids

There were studied the luminescent chemosensory properties of Eu(III) carboxylatodibenzoylmethanates with acetic and acrylic acids while the interaction with ammonia vapors. Quantitative measurements of the optical response showed that with an increase in the analyte concentration in the range of 3-330 ppm, a linear increase in the luminescence intensity of europium(III) is observed. The reversibility of the luminescent response was established, the limit of detection of ammonia was 3 ppm. The mechanism of the optical effect is revealed by the method of quantum chemical modeling: the interaction of ammonia with the sensor leads to the formation of a rigid structural fragment of H2O–NH3, which blocks the quenching effect of high-frequency OH vibrations on luminescence. The studied chemosensors have high sensitivity and selectivity and, thus, can be promising for creating ammonia detection sensors for food safety control and environmental monitoring.

scholarly journals Ratiometric Fluorescent Biosensors for Glucose and Lactate Using an Oxygen-Sensing Membrane

Biosensors ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 208
Author(s):  
Hong Dinh Duong ◽  
Jong Il Rhee
Keyword(s):  
Limit Of Detection ◽  
Oxygen Sensing ◽  
High Sensitivity ◽  
Glucose Sensing ◽  
Oxidation Reactions ◽  
Lactate Oxidase ◽  
Lactate Oxidation ◽  
Detection Range ◽  
Quenching Effect ◽  
Sensing Membrane

In this study, ratiometric fluorescent glucose and lactate biosensors were developed using a ratiometric fluorescent oxygen-sensing membrane immobilized with glucose oxidase (GOD) or lactate oxidase (LOX). Herein, the ratiometric fluorescent oxygen-sensing membrane was fabricated with the ratio of two emission wavelengths of platinum meso-tetra (pentafluorophenyl) porphyrin (PtP) doped in polystyrene particles and coumarin 6 (C6) captured into silica particles. The operation mechanism of the sensing membranes was based on (i) the fluorescence quenching effect of the PtP dye by oxygen molecules, and (ii) the consumption of oxygen levels in the glucose or lactate oxidation reactions under the catalysis of GOD or LOX. The ratiometric fluorescent glucose-sensing membrane showed high sensitivity to glucose in the range of 0.1–2 mM, with a limit of detection (LOD) of 0.031 mM, whereas the ratiometric fluorescent lactate-sensing membrane showed the linear detection range of 0.1–0.8 mM, with an LOD of 0.06 mM. These sensing membranes also showed good selectivity, fast reversibility, and stability over long-term use. They were applied to detect glucose and lactate in artificial human serum, and they provided reliable measurement results.

scholarly journals Label-Free Split Aptamer Sensor for Femtomolar Detection of Dopamine by Means of Flexible Organic Electrochemical Transistors

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2577 ◽  
Author(s):  
Yuanying Liang ◽  
Ting Guo ◽  
Lei Zhou ◽  
Andreas Offenhäusser ◽  
Dirk Mayer
Keyword(s):  
Detection Limit ◽  
Electrochemical Sensors ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Label Free ◽  
Dopamine Detection ◽  
Electrochemical Transistor ◽  
Sensitivity And Selectivity

The detection of chemical messenger molecules, such as neurotransmitters in nervous systems, demands high sensitivity to measure small variations, selectivity to eliminate interferences from analogues, and compliant devices to be minimally invasive to soft tissue. Here, an organic electrochemical transistor (OECT) embedded in a flexible polyimide substrate is utilized as transducer to realize a highly sensitive dopamine aptasensor. A split aptamer is tethered to a gold gate electrode and the analyte binding can be detected optionally either via an amperometric or a potentiometric transducer principle. The amperometric sensor can detect dopamine with a limit of detection of 1 μM, while the novel flexible OECT-based biosensor exhibits an ultralow detection limit down to the concentration of 0.5 fM, which is lower than all previously reported electrochemical sensors for dopamine detection. The low detection limit can be attributed to the intrinsic amplification properties of OECTs. Furthermore, a significant response to dopamine inputs among interfering analogues hallmarks the selective detection capabilities of this sensor. The high sensitivity and selectivity, as well as the flexible properties of the OECT-based aptasensor, are promising features for their integration in neuronal probes for the in vitro or in vivo detection of neurochemical signals.

scholarly journals Development of the High Sensitivity and Selectivity Method for the Determination of Histamine in Fish and Fish Sauce from Vietnam by UPLC-MS/MS

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Quang Hieu Tran ◽  
Thanh Tan Nguyen ◽  
Kim Phuong Pham
Keyword(s):  
Limit Of Detection ◽  
High Sensitivity ◽  
Fish Sauce ◽  
Limit Of Quantification ◽  
Fish Samples ◽  
The Matrix ◽  
Liquid Chromatography Tandem Mass ◽  
Sensitivity And Selectivity ◽  
Liquid Chromatographic

A selective, sensitive, and rapid method by using ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for the determination of histamine in fish and fish sauce was developed. The optimal conditions of liquid chromatographic separation and mass spectroscopy of histamine have also been investigated. The linear ranges of the method were 20.0 ÷ 1000 ng/mL, and the corresponding correlation coefficient was 0.9993. Mean recoveries of the analyte at three spike levels (low, medium, and high) were within the range of 98.5% ÷ 102.5% (n = 7). The limit of detection (LOD) and limit of quantification (LOQ) values were 3.83 and 11.50 ng/mL for the fish sauce sample and 4.71 and 14.12 ng/mL for the fish sample, respectively. The influence of the matrix effect on the accuracy, repeatability, and recovery of the method was negligible. The recommended method was applied to determine the content of this substance in 21 fish sauce samples and 4 kinds of fish samples, which were collected from Ho Chi Minh City, Vietnam, in 2019.

scholarly journals A FRET-ICT Dual-Modulated Ratiometric Fluorescence Sensor for Monitoring and Bio-Imaging of Cellular Selenocysteine

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4999
Author(s):  
Zongcheng Wang ◽  
Chenhong Hao ◽  
Xiaofang Luo ◽  
Qiyao Wu ◽  
Chengliang Zhang ◽  
...  
Keyword(s):  
Real Time ◽  
Limit Of Detection ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
High Sensitivity ◽  
Fluorescence Sensor ◽  
Quantitative Detection ◽  
Fluorescence Signal ◽  
Ratiometric Fluorescence ◽  
Sensitivity And Selectivity

Since the fluctuation of cellular selenocysteine (Sec) concentration plays an all-important role in the development of numerous human disorders, the real-time fluorescence detection of Sec in living systems has attracted plenty of interest during the past decade. In order to obtain a faster and more sensitive small organic molecule fluorescence sensor for the Sec detection, a new ratiometric fluorescence sensor Q7 was designed based on the fluorescence resonance energy transfer (FRET) strategy with coumarin fluorophore as energy donor and 4-hydroxy naphthalimide fluorophore (with 2,4-dinitrobenzene sulfonate as fluorescence signal quencher and Sec-selective recognition site) as an energy acceptor. The sensor Q7 exhibited only a blue fluorescence signal, and displayed two well distinguished emission bands (blue and green) in the presence of Sec with ∆λ of 68 nm. Moreover, concentrations ranging of quantitative detection of Sec of Q7 was from 0 to 45 μM (limit of detection = 6.9 nM), with rapid ratiometric response, high sensitivity and selectivity capability. Impressively, the results of the living cell imaging test demonstrated Q7 has the potentiality of being an ideal sensor for real-time Sec detection in biosystems.

Mass Spectrographic Technique for the Determination of Molybdenum Additive in Tantalum Oxide Capacitor Films

1968 ◽  
Vol 22 (4) ◽  
pp. 318-320 ◽  
Author(s):  
D. L. Malm
Keyword(s):  
New York ◽  
Internal Standard ◽  
High Sensitivity ◽  
Linear Increase ◽  
Atomic Fraction ◽  
Average Deviation ◽  
Quantitative Measurements ◽  
Vacuum Technology ◽  
Tantalum Films ◽  
Molybdenum Concentration

Recent analytical demands in thin-film technology require a means for quantitative measurements of intentionally added impurities in sputtered tantalum capacitor films. The inherent high sensitivity and surface-sensing ability of the rf vacuum spark source mass spectograph suggest its usefulness for this study [A. J. Ahearn, “Sixth National Symposium on Vacuum Technology Transactions” (Pergamon Press, Inc., New York, 1960)]. It has been demonstrated that with the aid of an internal standard and a sample-scanning technique that samples the film on the substrate, thus eliminating any chemical separations, quantitative estimates of molybdenum additive in films 4000 Å thick can be made with an average deviation of ±23%. A concentration range of 0.02% to 3.1% atomic fraction of molybdenum in tantalum films was studied. Because adequate sensitivity is attained without consuming the entire available sample, it is reasonable to predict that sensitivities of 10 ppm atomic or less may be reached. Results show a linear increase in the molybdenum concentration as the molybdenum-to-tantalum sputtering-surface ratio increases. Once this relationship has been established, films with the desired molybdenum concentration can be produced without the need for further chemical analysis. Mass spectrographic results also indicate that the molybdenum additive is homogeneously distributed in the tantalum film.

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 Amine Detection Using Organic Field Effect Transistor Gas Sensors

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 13
Author(s):  
Panagiotis Mougkogiannis ◽  
Michael Turner ◽  
Krishna Persaud
Keyword(s):  
Low Power ◽  
Gas Sensors ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Organic Field Effect Transistors ◽  
Practical Applications ◽  
Empirical Prediction ◽  
Sensitivity And Selectivity

Low power gas sensors with high sensitivity and selectivity are desired for many practical applications. Devices based on organic field effect transistors are promising because they can be fabricated at modest cost and are low power devices. Organic field effect transistors fabricated in bottom-gate bottom-contact configuration using the organic semiconductor [2,5-(2-octyldodecyl)-3,6-diketopyrrolopyrrole-alt-5,5-(2,5-di(thien-2-yl)thieno] [3,2-b]thiophene) (DPP-T-TT) were systematically investigated to determine the response characteristics to a series of alkylamines and ammonia. The highest sensitivity was to dibutylamine with a limit of detection of 0.025 ppb, followed by n-butylamine, 0.056 ppb, and ammonia, 2.17 ppb. A model was constructed based on the Antoine equation that successfully allows the empirical prediction of the sensitivity and selectivity of the gas sensor to various analytes including amines and alcohols based on the Antoine C parameter and the heat of the vaporization of the analyte.

scholarly journals Smartphone-Based Microfluidic Colorimetric Sensor for Gaseous Formaldehyde Determination with High Sensitivity and Selectivity

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3141 ◽  
Author(s):  
Xiao-Liang Guo ◽  
Yan Chen ◽  
Hong-Lan Jiang ◽  
Xian-Bo Qiu ◽  
Du-Li Yu
Keyword(s):  
Microfluidic Chip ◽  
Limit Of Detection ◽  
Low Cost ◽  
Sick Building Syndrome ◽  
High Sensitivity ◽  
Colorimetric Sensor ◽  
World Health ◽  
Formaldehyde Determination ◽  
Sensitivity And Selectivity ◽  
Gaseous Formaldehyde

Formaldehyde is one of the most dangerous air pollutants, which can cause sick building syndrome. Thus, it is very crucial to precisely determine formaldehyde with a low cost and simple operation. In this paper, a smartphone-based microfluidic colorimetric sensor is devised for gaseous formaldehyde determination with high sensitivity and selectivity. Specifically, a novel microfluidic chip is proposed based on the 4-aminohydrazine-5-mercapto-1,2,4-triazole (AHMT) method to determine formaldehyde; the chip consists of two reagent reservoirs, one reaction reservoir and a mixing column. In this design to prevent the fluid from flowing out while letting the gas molecule in, a hydrophobic porous poly tetra fluoroethylene (PTFE) membrane is put on the top of the reaction reservoir. Using the microfluidic chip sensor, a smartphone-based formaldehyde determination system is developed, which makes the measuring process automated and simple. As per the experiment results, the limit-of-detection (LOD) of the system is as low as 0.01 ppm, which is much lower than the maximum exposure concentration (0.08 ppm) recommended by the World Health Organization (WHO). Moreover, the sensor is hardly affected by acetaldehyde, volatile organic compounds (VOCs) or acidic-alkaline, which shows great selectivity. Finally, the performance of the proposed sensor is verified by using it for the determination of formaldehyde in a newly decorated house.

scholarly journals Schiff-Based Fluorescent-ON Sensor L Synthesis and Its Application for Selective Determination of Cerium in Aqueous Media

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Maria Sadia ◽  
Jehangir Khan ◽  
Robina Naz ◽  
Muhammad Zahoor ◽  
Ezzat Khan ◽  
...  
Keyword(s):  
Metal Ion ◽  
Limit Of Detection ◽  
Fluorescent Sensor ◽  
Aqueous Media ◽  
High Sensitivity ◽  
Transition Metal Ions ◽  
Acetonitrile Solution ◽  
Selective Determination ◽  
Sensitivity And Selectivity

In the present study, a fluorescent sensor L for sensing of Ce3+ ion was designed and characterized by XRD, 1HNMR, and FTIR. Its fluorescence behavior towards metal ion was examined by fluorescence spectroscopy. Chelation-enhanced fluorescence was shown by the sensor L upon interaction with Ce3+ ion. This fluorescent sensor exhibits high sensitivity and selectivity towards Ce3+ ion in acetonitrile solution, forming 2 : 1 (L : M) complex as determined by Job’s plot. Association constant was found to be 1×107 M−1 estimated from the Benesi-Hildebrand plot. No significant interference was observed in the presence of other studied alkali, alkaline, and transition metal ions. A rapid response was observed when employed for the determination of Ce3+ ion in spiked water samples with a limit of detection equal to 3.4×10−8 M.

scholarly journals Potentiometric Signal Transduction for Selective Determination of 1-(3-Chlorophenyl)piperazine “Legal Ecstasy” Through Biomimetic Interaction Mechanism

Chemosensors ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 46
Author(s):  
Eman El-Naby
Keyword(s):  
Dynamic Range ◽  
Limit Of Detection ◽  
Interaction Mechanism ◽  
High Sensitivity ◽  
Fast Response ◽  
Polymeric Membrane ◽  
Selective Determination ◽  
Sensitivity And Selectivity ◽  
Pharmacologically Active

1-(3-chlorophenyl)piperazine (mCPP) is a wide spread new psychoactive substance produces stimulant and hallucinogenic effects similar to those sought from ecstasy. Hence, in the recent years, mCPP has been introduced by the organized crime through the darknet as a part of the illicit ecstasy market with a variable complex profile of pharmacologically active substances that pose problematic risk patterns among people who take these seized products. Accordingly, the design of selective sensors for the determination of mCPP is a very important demand. In this respect, a supramolecular architecture; [Na(15-crown-5)][BPh4] from the assembly of 15-crown-5 and sodium tetraphenylboron has been utilized as an ionophore, for the first time in the selective recognition of mCPP in conjunction with potassium tetrakis(p-chlorophenyl)borate and dioctylphthalate through polymeric membrane ion sensors. The ionophore exhibited a strong binding affinity that resulted in a high sensitivity with a slope closed to the ideal Nernstian value; 58.9 ± 0.43 mV/decade, a larger dynamic range from 10−6 to 10−2 M, a lower limit of detection down to 5.0 × 10−7 M and a fast response time of 5 s. Very important also is it was afforded excellent selectivity towards mCPP over psychoactive substances of major concern, providing a potentially useful system for the determination of mCPP in the illicit market. On comparison with the natural β-cyclodextrin as an ionophore, it exhibited more sensitivity and selectivity estimated to be the superior.

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