scholarly journals Detection of Bio-Relevant Metal Ions by Luminescent Ru(II)-Polypyridyl Based Sensors

2021 ◽  
Author(s):  
Pramod Kumar ◽  
Sushil Kumar
Keyword(s):  
Metal Ions ◽  
Photophysical Properties ◽  
Stokes Shift ◽  
Enzymatic Catalysis ◽  
Visible Region ◽  
Analytical Techniques ◽  
High Sensitivity ◽  
Dna And Rna ◽  
Physiological Processes ◽  
Living Organisms

Biorelevant metal ions such as Cu2+ and Fe2+/Fe3+ participate in various biological events which include electron transfer reactions, delivery and uptake of oxygen, DNA and RNA syntheses, and enzymatic catalysis to maintain fundamental physiological processes in living organisms. So far, several analytical techniques have been investigated for their precise detection; however, luminescence-based sensing is often superior due to its high sensitivity, selectivity, fast and easy operation and convenient cellular imaging. Owing to their immense photophysical and photochemical properties stemming from large Stokes shift, absorption in visible region, good photostability and long excited state lifetimes, Ru(II)-polypyridyl-based complexes have gained increasing interest as luminophores. Over past few decades, several Ru(II)-polypyridyl based chemosensors have rapidly been developed for detection of different biorelevant and other metal ions. The main object of this book chapter is to cover a majority of Ru(II)-polypyridyl based chemosensors showing a selective and sensitive detection of bio-relevant Cu2+ and Fe2+/Fe3+ ions. The photophysical properties of Ru(II) complexes, detection of metal ions, sensing mechanism and applications of these sensors are discussed at a length.

scholarly journals Recent Advances in the Electrochemical Sensing of Venlafaxine: An Antidepressant Drug and Environmental Contaminant

Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3675
Author(s):  
Somayeh Tajik ◽  
Hadi Beitollahi ◽  
Zahra Dourandish ◽  
Kaiqiang Zhang ◽  
Quyet Van Le ◽  
...  
Keyword(s):  
Antidepressant Drug ◽  
Analytical Techniques ◽  
High Sensitivity ◽  
Electrochemical Determination ◽  
Electrochemical Sensing ◽  
Carbon Paste ◽  
Low Concentrations ◽  
Adverse Influence ◽  
Living Organisms ◽  
Sensitivity Specificity

Venlafaxine (VEN), as one of the popular anti-depressants, is widely utilized for the treatment of major depressive disorder, panic disorder, as well as anxiety. This drug influences the chemicals in the brain, which may result in imbalance in depressed individuals. However, venlafaxine and its metabolites are contaminants in water. They have exerted an adverse influence on living organisms through their migration and transformation in various forms of adsorption, photolysis, hydrolysis, and biodegradation followed by the formation of various active compounds in the environment. Hence, it is crucial to determine VEN with low concentrations in high sensitivity, specificity, and reproducibility. Some analytical techniques have been practically designed to quantify VEN. However, electroanalytical procedures have been of interest due to the superior advantages in comparison to conventional techniques, because such methods feature rapidity, simplicity, sensitivity, and affordability. Therefore, this mini-review aims to present the electrochemical determination of VEN with diverse electrodes, such as carbon paste electrodes, glassy carbon electrodes, mercury-based electrodes, screen-printed electrodes, pencil graphite electrodes, and ion-selective electrodes.

Positronium as a biomarker of hypoxia

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Paweł Moskal ◽  
Ewa Ł. Stępień
Keyword(s):  
Partial Pressure ◽  
High Sensitivity ◽  
Partial Pressure Of Oxygen ◽  
Physiological Processes ◽  
Positron Emission ◽  
Positronium Lifetime ◽  
Total Body ◽  
Living Organisms ◽  
Cancer Tissues

Abstract In this review article, we present arguments demonstrating that the advent of high sensitivity total-body PET systems and the invention of the method of positronium imaging, open realistic perspectives for the application of positronium as a biomarker for in-vivo assessment of the degree of hypoxia. Hypoxia is a state or condition, in which the availability of oxygen is not sufficient to support physiological processes in tissue and organs. Positronium is a metastable atom formed from electron and positron which is copiously produced in the intramolecular spaces in the living organisms undergoing positron emission tomography (PET). Properties of positronium, such as e.g., lifetime, depend on the size of intramolecular spaces and the concentration in them of oxygen molecules. Therefore, information on the partial pressure of oxygen (pO2) in the tissue may be derived from the positronium lifetime measurement. The partial pressure of oxygen differs between healthy and cancer tissues in the range from 10 to 50 mmHg. Such differences of pO2 result in the change of ortho-positronium lifetime e.g., in water by about 2–7 ps. Thus, the application of positronium as a biomarker of hypoxia requires the determination of the mean positronium lifetime with the resolution in the order of 2 ps. We argue that such resolution is in principle achievable for organ-wise positronium imaging with the total-body PET systems.

scholarly journals Influence of Krakow Winter and Summer Dusts on the Redox Cycling of Vitamin B12a in the Presence of Ascorbic Acid

Atmosphere ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1050
Author(s):  
Justyna Polaczek ◽  
Angelika Jodłowska ◽  
Grażyna Stochel ◽  
Rudi van Eldik
Keyword(s):  
Air Pollution ◽  
Ascorbic Acid ◽  
Analytical Techniques ◽  
Redox Cycling ◽  
Limit Values ◽  
Physiological Processes ◽  
European Environmental Agency ◽  
Living Organisms ◽  
Pm2.5 And Pm10

Air pollution remains a serious problem in Krakow, Poland. According to the European Environmental Agency, annual mean levels of both PM2.5 and PM10 recorded in Krakow are much higher than EU limit values. Thus, the influence of particulate matter (PM) on the function of living organisms, as well as different physiological processes, is an urgent subject to be studied. The reported research forms part of the multi-disciplinary project ‘Air Pollution versus Autoimmunity: Role of multiphase aqueous Inorganic Chemistry,’ which aims to demonstrate the PM effect on the immune system. The present studies focused on the role of dust collected in Krakow on the redox cycling of vitamin B12a in the presence of ascorbic acid. Dust samples collected during the winter 2019/2020 and summer 2020 months in the city center of Krakow were characterized using various analytical techniques. The influence of Krakow dusts on the kinetics of the reaction between nitrocobalamin and ascorbic acid was confirmed and discussed in terms of the composition of the samples. Possible reasons for the reported findings are provided.

scholarly journals Acridino-Diaza-20-Crown-6 Ethers: New Macrocyclic Hosts for Optochemical Metal Ion Sensing

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4043
Author(s):  
Ádám Golcs ◽  
Korinna Kovács ◽  
Panna Vezse ◽  
Tünde Tóth ◽  
Péter Huszthy
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Photophysical Properties ◽  
High Sensitivity ◽  
Spectroscopic Studies ◽  
New Host ◽  
Practical Applications ◽  
Ion Sensing ◽  
Sensing Applications ◽  
Sensor Molecules

Acridino-diaza-20-crown-6 ether derivatives as new turn-on type fluorescent chemosensors with an excellent functionality and photophysical properties have been designed and synthesized for metal ion-selective optochemical sensing applications. Spectroscopic studies revealed that in an acetonitrile-based semi-aqueous medium, the sensor molecules exhibited a remarkable fluorescence enhancement with high sensitivity only toward Zn2+, Al3+ and Bi3+, among 23 different metal ions. Studies on complexation showed a great coordinating ability of logK > 4.7 with a 1:1 complex stoichiometry in each case. The detection limits were found to be from 59 nM to micromoles. The new ionophores enabled an optical response without being affected either by the pH in the range of 5.5–7.5, or the presence of various anions or competing metal ions. Varying the N-substituents of the new host-backbone provides diverse opportunities in both immobilization and practical applications without influencing the molecular recognition abilities.

Importance of Bodipy-based Chemosensors for Cations and Anions in Bioimaging Applications

2020 ◽  
Vol 17 ◽  
Author(s):  
Ahmed Nuri Kursunlu ◽  
Elif Bastug ◽  
Ersin Guler
Keyword(s):  
Photophysical Properties ◽  
Direct Determination ◽  
Spectroscopic Properties ◽  
Selective Detection ◽  
Fluorescent Chemosensors ◽  
Design Strategies ◽  
Online Activity ◽  
Fluorescence Studies ◽  
Bio Imaging ◽  
Living Organisms

Background: Chemosensor compounds are useful for sensitive selective detection of cations and anions with fluorophore groups in an attempt to develop the effective selectivity of the sensors. Although familiar fluorescent sensors utilizing inter-molecular interactions with the cations and anions, an extraordinary endeavor was executed the preparation of fluorescent-based sensor compounds. 4,4-difluoro-4- bora-3a,4a-diaza-s-indacene (Bodipy) and its derivatives were firstly used as an agent in the imaging of biomolecules due to their interesting structures, complexation, and fluorogenic properties. Among the fluorescent chemosensors used for cations and anions, Bodipy-based probes stand out owing to the excellent properties such as sharp emission profile, high stability, etc. In this review, we emphasize the Bodipy-based chemosensor compounds, which have been used to image cations and anions in living cells, because of as well as the biocompatibility and spectroscopic properties. Methods: Research and online content related to chemosensor online activity is reviewed. The advances, sensing mechanisms and design strategies of the fluorophore exploiting selective detection of some cation and anions with Bodipy-based chemosensors are explained. It could be claimed that the using of Bodipy-based chemosensors is very important for cations and anions in bio-imaging applications. Results: Molecular sensors or chemosensors are molecules that show a change can be detected when affected by the analyte. They are capable of producing a measurable signal when they are selective for a particular molecule. Molecular and ion recognition that it is important in biological systems such as enzymes, genes, environment, and chemical fields. Due to the toxic properties of many heavy metal ions, it is of great importance to identify these metals due to their harmful effects on living metabolism and the pollution they create in the environment. This process can be performed with analytical methods based on atomic absorption and emission. The fluorescence methods among chemosensor systems have many advantages such as sensitivity, selectivity, low price, simplicity of using the instrument and direct determination in solutions. The fluorescence studies can be applied at nanomolar concentrations. Conclusion: During a few decades, a lot of Bodipy-based chemosensors for the detection of cations & anions have been investigated in bio-imaging applications. For the Bodipy-based fluorescent chemosensors, the Bodipy derivatives were prepared by different ligand groups for the illumination of the photophysical and photochemical properties. The synthesized Bodipy-based chemosensors have remarkable photophysical properties, such as a high quantum yield, strong molar absorption coefficient etc. Moreover, these chemosensors were successfully implemented on living organisms for the detection of analytes.

scholarly journals Electroanalytical Techniques for the Detection of Selenium as a Biologically and Environmentally Significant Analyte—A Short Review

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1768
Author(s):  
Miroslav Rievaj ◽  
Eva Culková ◽  
Damiána Šandorová ◽  
Zuzana Lukáčová-Chomisteková ◽  
Renata Bellová ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Essential Element ◽  
Analytical Techniques ◽  
High Sensitivity ◽  
Stripping Voltammetry ◽  
Short Review ◽  
Electroanalytical Methods ◽  
High Concentrations ◽  
Speed Of Analysis

This short review deals with the properties and significance of the determination of selenium, which is in trace amounts an essential element for animals and humans, but toxic at high concentrations. It may cause oxidative stress in cells, which leads to the chronic disease called selenosis. Several analytical techniques have been developed for its detection, but electroanalytical methods are advantageous due to simple sample preparation, speed of analysis and high sensitivity of measurements, especially in the case of stripping voltammetry very low detection limits even in picomoles per liter can be reached. A variety of working electrodes based on mercury, carbon, silver, platinum and gold materials were applied to the analysis of selenium in various samples. Only selenium in oxidation state + IV is electroactive therefore the most of voltammetric determinations are devoted to it. However, it is possible to detect also other forms of selenium by indirect electrochemistry approach.

scholarly journals Detection of metal ions in biological systems: A review

2020 ◽  
Vol 39 (1) ◽  
pp. 231-246 ◽  
Author(s):  
Xian Zheng ◽  
Wenyu Cheng ◽  
Chendong Ji ◽  
Jin Zhang ◽  
Meizhen Yin
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Metabolic Regulation ◽  
Organic Dyes ◽  
Biological Systems ◽  
High Sensitivity ◽  
Transportation Energy ◽  
Material Transportation ◽  
High Fluorescence ◽  
Metal Ion Detection

Abstract Metal ions are widely present in biological systems and participate in many critical biochemical processes such as material transportation, energy conversion, information transmission and metabolic regulation, making them indispensable substance in our body. They can cause health problems when deficiency or excess occurs. To understand various metabolic processes and facilitate diseases diagnosis, it is very important to measure the content and monitor the distribution of metal ions in individual cells, tissues and whole organisms. Among the various methods for metal ion detection, fluorescent sensors with organic dyes have attracted tremendous attention due to many advantages such as high fluorescence quantum yield, facile modification approaches and biocompatibility in addition to operation ease, high sensitivity, fast detection speed, and real-time detection. This review summarizes the recent progress on the detection and imaging of the metal ions in biological systems including Na+, K+, Ca2+, Mg2+, Fe2+/Fe3+, Zn2+, and Cu2+ provides an opinion on remaining challenges to be addressed in this field.

scholarly journals Metal Binding Proteins

Encyclopedia ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 261-292
Author(s):  
Eugene A. Permyakov
Keyword(s):  
Metal Ions ◽  
Metal Binding ◽  
Transition Metal Ions ◽  
Short Review ◽  
Sodium Potassium ◽  
Physical Chemical ◽  
Physiological Properties ◽  
Cell Processes ◽  
Living Organisms ◽  
Potassium Magnesium

Metal ions play several major roles in proteins: structural, regulatory, and enzymatic. The binding of some metal ions increase stability of proteins or protein domains. Some metal ions can regulate various cell processes being first, second, or third messengers. Some metal ions, especially transition metal ions, take part in catalysis in many enzymes. From ten to twelve metals are vitally important for activity of living organisms: sodium, potassium, magnesium, calcium, manganese, iron, cobalt, zinc, nickel, vanadium, molybdenum, and tungsten. This short review is devoted to structural, physical, chemical, and physiological properties of proteins, which specifically bind these metal cations.

scholarly journals Overview of Popular Techniques of Raman Spectroscopy and Their Potential in the Study of Plant Tissues

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1537
Author(s):  
Aneta Saletnik ◽  
Bogdan Saletnik ◽  
Czesław Puchalski
Keyword(s):  
Raman Spectroscopy ◽  
Cell Walls ◽  
Structural Changes ◽  
Spatial Information ◽  
Technological Development ◽  
Analytical Techniques ◽  
High Sensitivity ◽  
Plant Tissues ◽  
Wide Range ◽  
Identification Technique

Raman spectroscopy is one of the main analytical techniques used in optical metrology. It is a vibration, marker-free technique that provides insight into the structure and composition of tissues and cells at the molecular level. Raman spectroscopy is an outstanding material identification technique. It provides spatial information of vibrations from complex biological samples which renders it a very accurate tool for the analysis of highly complex plant tissues. Raman spectra can be used as a fingerprint tool for a very wide range of compounds. Raman spectroscopy enables all the polymers that build the cell walls of plants to be tracked simultaneously; it facilitates the analysis of both the molecular composition and the molecular structure of cell walls. Due to its high sensitivity to even minute structural changes, this method is used for comparative tests. The introduction of new and improved Raman techniques by scientists as well as the constant technological development of the apparatus has resulted in an increased importance of Raman spectroscopy in the discovery and defining of tissues and the processes taking place in them.

A phthalocyanine-based fluorescent sensor for Zn2+ ion

2013 ◽  
Vol 17 (01n02) ◽  
pp. 99-103 ◽  
Author(s):  
Hui He ◽  
Jian-Yong Liu ◽  
Dennis K.P. Ng
Keyword(s):  
Metal Ions ◽  
Spectral Properties ◽  
Fluorescence Spectra ◽  
Near Infrared ◽  
Fluorescent Sensor ◽  
High Sensitivity ◽  
Absorption And Fluorescence Spectra

This paper describes the preparation and spectral properties of a near-infrared fluorophore in which two bis(2-picolyl)amino moieties are axially linked to a silicon(IV) phthalocyanine core. The effects of various metal ions on its absorption and fluorescence spectra have been examined. The results indicate that this compound shows a high sensitivity and moderate selectivity toward Zn2+ ion.

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