Optical detn. Visualized Exp. ACS Appl. Nano Mater. The selectivity of ionophore-based sensors is crucial to real applications such as clin.
Previous ion-selective nanosensors developed from amphiphilic block copolymers are attractive because of simple fabrication, high stability, and versatility. However, the selectivity was reduced compared with polymeric ion-selective membranes.
Here, the authors present ionophore-based nanosensors from graft copolymer nanodots The improved selectivity was ascribed to the high ion-carrier stability consts. Besides response in the light absorption mode, an intriguing energy transfer in the nanodots resulted in a ratiometric and dual-emission sensing mode. Nanosensors delivered to HeLa cells through endocytosis were found to accumulate in endosomes and lysosomes. As a preliminary application, the sodium ion concn.
The authors present a convenient pptn. The nanosphere matrix is composed of bis- 2-ethylhexyl sebacate DOS and a triblock copolymer Pluronic F, which also functions as a surfactant to stabilize the nanoparticle. The particles can be prepd. Dynamic light scattering shows that these particles have a monodisperse size distribution with an av. A newly reported oxazinoindoline Ox as well as a Nile blue deriv.
Owing to the very small size of the nanospheres, the suspension contg. In the addnl. DOI: Quantitative Chemical Analysis ; W. Freeman and Company , Guidelines for Drinking-Water Quality ; Astrobiology , 13 , — , DOI: Mary Ann Liebert, Inc.
This site provides an ideal field environment in which to test our understanding of Fe isotope fractionations derived from lab. Fe II. However, the degree of fractionation is less than that expected in a closed system at isotopic equil. We suggest two explanations for the obsd. Fe isotope compns. One is that light Fe isotopes partition into a sorbed component and ppt. These findings provide evidence that silica plays an important role in governing Fe isotope fractionation factors between reduced and oxidized Fe.
Under conditions of low ambient oxygen, such as may be found on early Earth or Mars, significantly larger Fe isotope variations are predicted, reflecting the more likely attainment of Fe isotope equil. Key Words: Isotope fractionation-Iron oxidn. A variety of biochem.
Unlike the major fraction of bioiron which is protein bound, the labile bioiron is chelatable and therefore amenable for detection by metal-sensing devices that are coupled to chelation moieties. The present review deals with the detection of various labile forms of iron present in living cells and in fluids of biol.
The main focus of the review is on the design and application of fluorescent probes as anal. This makes it a versatile starting material for synthetic org.
In this tutorial review we examine how the chem. They are utilized for many anal. Water Res. A rapid and simple preconcn. HCl and complexed with Bathocuproine. The Bathocuproine complex is collected on a nitrocellulose membrane filter. The membrane filter and the complex are dissolved in a small vol. It is less tedious than the conventional solvent extn. The detection limit is 0. Toxicological Profile for Copper. Public Heal. A Review. Fluorescent sensors for transition metal ions were synthesized by linking a light-emitting subunit, anthracene, to a polyaza chelating subunit, either a dioxotetraamine or a tetraamine.
The selective recognition of CuII and NiII among other transition and nontransition metal ions is signaled through full quenching of fluorescence; discrimination between the two ions can be achieved by performing titrns.
The system contg. Chemosphere , 68 , — , DOI: Elsevier Ltd. The spontaneous chem. Although in many practical situations the nature of the end-products is of less interest than the oxidn. This paper uses basic aquatic-chem. The oxidn. Between pH 5 and 8 the Fe OH 02 concn. The paper presents a heuristic overview of the pH dependent kinetics of aq. Chemical Tools for Detecting Fe Ions. Society for Free Radical Research Japan. Owing to its distinctive electrochem.
This redox activity can also potentially produce cellular damage and death, and numerous diseases are related to iron overload resulting from the dysfunction of the iron regulatory system. In this case, "free iron" or "labile iron," which refers to iron ion weakly bound or not bound to proteins, causes aberrant prodn. With the aim of elucidating the variation of labile iron involved in pathol. Since iron ions show unique reactivity depending on its redox state, i. The scope of this review article covers from classical chromogenic to newly emerging chem.
In particular, chem. Fluorescence Stability of 8-Hydroxyquinoline Aluminum. Elsevier Science B. The fluorescence stabilities of Alq3 films were compared before and after UV irradn. They were analyzed by using a UV-visible absorption spectrophotometer, an in situ fluorescence spectrometer, attenuated XPS, and a nanosecond fluorescence spectrophotometer. These results indicate that H2O and oxygen aid the photodegrdn. The large vols.
AMD sludge typically contains a heterogeneous mixt. However, purified Fe and Al hydroxides have potential com. Based on the soly. The recommended pH for Fe pptn. AMD water after Fe removal was used as source water for Al recovery. Al pptd. Liquid—Liquid Extraction. January 15 , Talanta , 41 , — , DOI: A new sensitive and selective spectrophotometric method for the detn. Copper I in an aq.
The absorbance of the orange membrane was measured at nm using a spectrophotometer, and the concn. The reproducibility of the absorbances of membranes was 0. Actuators, B , , 19 — 32 , DOI: Combinatorial synthesis and high throughput screening of the hydrogel matrix.
A combinatorial library of hydrogels is produced by radical polymn. Six acrylamide monomers are used to produce a library of 21 crosslinked hydrogel matrixes. The swelling of all hydrogels is detd. The partition coeff. Hydrogels with sulfonic -SO-3 groups show large values of partition coeffs. Since the phenanthroline could be released from the hydrogel, bathophenanthroline BPhen which is not released is used as ligand. The visual detection of color gives a detection limit of 0. Little interference of different common ions is found.
A special set-up is made which allows spectrophotometric measurement of the complex inside the gel. The detection limit is found to be of ca. Using the sensor, the iron content in milk is measured directly demonstrating the use of the sensor to measure free iron in opaque liqs. The non-covalent retention of ligands and complexes inside polymeric hydrogels seems to be a suitable method for building specific ion sensors.
Jahad Daneshgahi. Fe II in an aq. The absorbance of the red-orange membrane is measured at nm using a spectrophotometer. The influence of type and concn. The detectable limit of Fe in a sample soln. The effect of various cationic interferences on detn. National Academy of Sciences. Regulation of sodium flux across the cell membrane plays a vital role in the generation of action potentials and regulation of membrane excitability in cells such as cardiomyocytes and neurons.
Alteration of sodium channel function has been implicated in diseases such as epilepsy, long QT syndrome, and heart failure. However, single cell imaging of sodium dynamics has been limited due to the narrow selection of fluorescent sodium indicators available to researchers. Here we report, the detection of spatially defined sodium activity during action potentials. Fluorescent nanosensors that measure sodium in real-time, are reversible and are completely selective over other cations such as potassium that were used to image sodium.
The use of the nanosensors in vitro was validated by detg. Spatial information of sodium concns. Jewell, Megan P. Kirk; Zemanick, Edith T. American Society for Microbiology. Bacterial biofilms can form persistent infections on wounds and implanted medical devices and are assocd. These infections are medically difficult to treat, as biofilms are more resistant to antibiotic attack than their planktonic counterparts.
An understanding of the spatial and temporal variation in the metab. To this end, we developed oxygen-sensitive luminescent nanosensors to measure three-dimensional 3D oxygen gradients, an application of which is demonstrated here with Pseudomonas aeruginosa biofilms.
The method was applied here and improves on traditional one-dimensional 1D methods of measuring oxygen profiles by investigating the spatial and temporal variation of oxygen concn. We obsd. Due to the spatial and temporal nature of our approach, we also identified spatial and temporal inhomogeneities in the biofilm metab. Continuously tracking bioanalytes in vivo will enable clinicians and researchers to profile normal physiol. Current in vivo monitoring system designs are limited by invasive implantation procedures and biofouling, limiting the utility of these tools for obtaining physiol.
In this work, we demonstrate the first success in optically tracking histamine levels in vivo using a modular, injectable sensing platform based on diamine oxidase and a phosphorescent oxygen nanosensor. Our new approach increases the range of measurable analytes by combining an enzymic recognition element with a reversible nanosensor capable of measuring the effects of enzymic activity. We use these enzyme nanosensors EnzNS to monitor the in vivo histamine dynamics as the concn.
The EnzNS system measured kinetics that match those reported from ex vivo measurements. This work establishes a modular approach to in vivo nanosensor design for measuring a broad range of potential target analytes.
Simply replacing the recognition enzyme, or both the enzyme and nanosensor, can produce a new sensor system capable of measuring a wide range of specific anal. In Vivo Biosensing: Progress and Perspectives. In vivo biosensors are emerging as powerful tools in biomedical research and diagnostic medicine.
Distinct from "labels" or "imaging", in vivo biosensors are designed for the continuous and long-term monitoring of target analytes or biomarkers in real biol. Due to the challenges assocd. However, the authors identified several case studies and a range of emerging materials likely to lead to significant developments in the field. A Critical Review. A critical review. An extensive crit. DLLME combined with chromatog. The review emphasizes the procedures used for food samples pretreatment, which are very different from the DLLME procedures generally used for water samples.
The main contribution of this work is its crit. RSC Adv. Optical sensors have numerous pos. Recently, there has been a strong research focus on using phosphorescent readout mechanisms, specifically from long-lifetime phosphorescent or 'persistent luminescence' particles, for in vitro and in vivo sensors. Persistent luminescence readouts can avoid cellular autofluorescence during biol.
In this study, we show for the first time an ionophore-based optical bulk optode sensor that utilizes persistent luminescence microparticles for ion detection. To achieve this, we combined long-lifetime strontium aluminate-based glow-in-the-dark microparticles with a non-fluorescent pH-responsive dye in a hydrophobic plasticized polymer membrane along with traditional ionophore-based optical sensor components to create a phosphorescent 'Glow Sensor'.
The non-fluorescent pH indicator dye gates the strontium aluminate luminescence signal so that it decreases in magnitude with increasing sodium concn. We characterized the Glow Sensor in terms of emission lifetime, dynamic range, response time, reversibility, selectivity, and stability. On the Design of Fluorescent Ratiometric Nanosensors.
Advances in nanoparticle technol. In particular, new nanoparticle-based sensors have appeared able to give quant. This article describes the methodologies developed so far in the design of such nanosensors. In particular, the different approaches to immobilize fluorescent chemosensor dyes to nanoparticles are presented.
Concept designs of ratiometric nanosensors in terms of compn. Fluorescence probes serves as unique detection methods for its simplicity and low detection limit LOD and esp. Research on the probes has already sprouted during the last decade with the help of its mol.
She participates in research projects across Africa, as well as in Asia and South America where a key interest is the support and mentoring of investigator-initiated pharmacology research projects.
Computational scientist with expertise in the development of Parallel and Hybrid model computer codes for application to chemical, life and biomedical sciences.
Research is balanced between development of life science software and its application to biomedical projects where more recently the biomedical application has been cancer. Scientific interests are focused on the roles that carbohydrates play in biological processes. A demonstration of the application of computational expertise is his use of molecular modelling simulations to develop therapeutics for cancer as well as his use of data analytics and informatics methods to develop diagnostics and prognostics for cancer.
Research focuses on the molecular genetic changes in oesophageal cancer using a whole genome sequencing approach to identify mutation signatures, epigenetic changes, gene mutation, deletions and insertions with specific relevance to early diagnosis and targeted therapeutic interventions in cancer.
Is one of the very rare cardiologists in South Africa who is clinically active and trained in fundamental molecular laboratory methods, combining laboratory and epidemiological skills. Widely published in both local and international journals and books of various topics related to cardiovascular medicine. Internationally recognized for her outstanding work in the area of heart failure.
Collaborations with a range of prestigious national and international clinical and academic centers. TXT For Later. Related titles. Carousel Previous Carousel Next. Jump to Page. Search inside document. Related Interests Nature. Evan Husada Sidrap. Drs Mulatua. Christian Eduard de Dios. Faeeza Bianca Quiamco. Fitria Hardiyanti. Oz Nugroho. Novia Ranti Unforgettable. Edmund Halley. Agrifina Helga. Anonymous vFaknH. Iyaz Meindra. Skripsi Ptk.
Irna Wahyuni.
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