X-ray photoemission studies of the interaction of metals and metal ions with DNA

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Esha Mishra ◽  
Subrata Majumder ◽  
Shikha Varma ◽  
Peter A. Dowben

Abstract X-ray Photoelectron Spectroscopy (XPS) has been used to study the interactions of heavy metal ions with DNA with some success. Surface sensitivity and selectivity of XPS are advantageous for identifying and characterizing the chemical and elemental structure of the DNA to metal interaction. This review summarizes the status of what amounts to a large part of the photoemission investigations of biomolecule interactions with metals and offers insight into the mechanism for heavy metal-bio interface interactions. Specifically, it is seen that metal interaction with DNA results in conformational changes in the DNA structure.

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Shengtao Hei ◽  
Yan Jin ◽  
Fumin Zhang

Porousγ-Fe2O3nanoparticles were prepared via a solid-state conversion process of a mesoporous iron(III) carboxylate crystal, MIL-100(Fe). First, the MIL-100(Fe) crystal that served as the template of the metal oxide was synthesized by a low-temperature (<100°C) synthesis route. Subsequently, the porousγ-Fe2O3nanoparticles were fabricated by facile thermolysis of the MIL-100(Fe) powders via a two-step calcination treatment. The obtainedγ-Fe2O3was characterized by X-ray diffraction (XRD), N2adsorption, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) techniques, and then used as an adsorbent for heavy metal ions removal in water treatment. This study illustrates that the metal-organic frameworks may be suitable precursors for the fabrication of metal oxides nanomaterials with large specific surface area, and the prepared porousγ-Fe2O3exhibits a superior adsorption performance for As(V) and As(III) ions removal in water treatment.


2020 ◽  
Vol 82 (12) ◽  
pp. 2962-2974
Author(s):  
Hua Deng ◽  
Qiuyan Li ◽  
Meijia Huang ◽  
Anyu Li ◽  
Junyu Zhang ◽  
...  

Abstract Low-cost banana stalk (Musa nana Lour.) biochar was prepared using oxygen-limited pyrolysis (at 500 °C and used), to remove heavy metal ions (including Zn(II), Mn(II) and Cu(II)) from aqueous solution. Adsorption experiments showed that the initial solution pH affected the ability of the biochar to adsorb heavy metal ions in single- and polymetal systems. Compared to Mn(II) and Zn(II), the biochar exhibited highly selective Cu(II) adsorption. The adsorption kinetics of all three metal ions followed the pseudo-second-order kinetic equation. The isotherm data demonstrated the Langmuir model fit for Zn(II), Mn(II) and Cu(II). The results showed that the chemical adsorption of single molecules was the main heavy metal removal mechanism. The maximum adsorption capacities (mg·g−1) were ranked as Cu(II) (134.88) &gt; Mn(II) (109.10) &gt; Zn(II) (108.10)) by the single-metal adsorption isotherms at 298 K. Moreover, characterization analysis was performed using Fourier transform infrared spectroscopy, the Brunauer-Emmett-Teller method, scanning electron microscopy with energy-dispersive X-ray spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The results revealed that ion exchange was likely crucial in Mn(II) and Zn(II) removal, while C-O, O-H and C = O possibly were key to Cu(II) removal by complexing or other reactions.


1984 ◽  
Vol 13 (2) ◽  
pp. 83-86 ◽  
Author(s):  
Michihiro Murata ◽  
Masayuki Omatsu ◽  
Syuji Mushimoto

2014 ◽  
Vol 887-888 ◽  
pp. 388-394 ◽  
Author(s):  
Xin Hua Liu ◽  
Yi Deng ◽  
Yu Chuan Zhang ◽  
Yin Hang Zhou

The structures and optical performances of TiO2doped with 4thperiodic transition metal ions were investigated in this paper. The characterization results of X-ray photoelectron spectroscopy and X-ray diffraction showed that the transition metal ions existed in oxidative states, and composites formed because of the reaction between doped metal ions and TiO2. The absorption spectroscopy of TiO2doped with zinc was mainly in ultraviolet region, close to that of the pure TiO2. While for TiO2doped with other transition metal ions including V, Cr, Mn, Fe, Co, Ni and Cu ions, the absorption spectroscopies covered ultraviolet region and visible light region, much broader than that of the pure TiO2.


Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1876 ◽  
Author(s):  
Maxim V. Zdorovets ◽  
Ilya V. Korolkov ◽  
Arman B. Yeszhanov ◽  
Yevgeniy G. Gorin

Nowadays, water quality monitoring is an essential task since environmental contamination and human exposure to heavy metals increased. Sensors that are able to detect ever lower concentrations of heavy metal ions with greater accuracy and speed are needed to effectively monitor water quality and prevent poisoning. This article shows studies of the modification of flexible track-etched membranes as the basis for the sensor with various polymers and their influence on the accuracy of detection of copper, cadmium, and lead ions in water. We report the UV-induced graft (co)polymerization of acrylic acid (AA) and 4-vinylpyridine (4-VPy) on poly(ethylene terephthalate) track-etched membrane (PET TeMs) and use them after platinum layer sputtering in square wave anodic stripping voltammetry (SW-ASV) for detection of Cu2+, Cd2+, and Pb2+. Optimal conditions leading to functionalization of the surface and retention of the pore structure were found. Modified membranes were characterized by SEM, FTIR, X-ray photoelectron spectroscopy (XPS) and colorimetric analysis. The dependence of the modification method on the sensitivity of the sensor was shown. Membrane modified with polyacrylic acid (PET TeMs-g-PAA), poly(4-vinylpyridine) (PET TeMs-g-P4VPy), and their copolymer (PET TeMs-g-P4VPy/PAA) with average grafting yield of 3% have been found to be sensitive to µg/L concentration of copper, lead, and cadmium ions. Limits of detection (LOD) for sensors based on PET TeMs-g-PAA are 2.22, 1.05, and 2.53 µg/L for Cu2+, Pb2+, and Cd2+, respectively. LODs for sensors based on PET TeMs-g-P4VPy are 5.23 µg/L (Cu2+), 1.78 µg/L (Pb2+), and 3.64 µg/L (Cd2+) µg/L. PET TeMs-g-P4VPy/PAA electrodes are found to be sensitive with LODs of 0.74 µg/L(Cu2+), 1.13 µg/L (Pb2+), and 2.07 µg/L(Cd2+). Thus, it was shown that the modification of membranes by copolymers with carboxylic and amino groups leads to more accurate detection of heavy metal ions, associated with the formation of more stable complexes.


Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 245 ◽  
Author(s):  
Sada Venkateswarlu ◽  
Saravanan Govindaraju ◽  
Roopkumar Sangubotla ◽  
Jongsung Kim ◽  
Min-Ho Lee ◽  
...  

The enormous ongoing industrial development has caused serious water pollution which has become a major crisis, particularly in developing countries. Among the various water pollutants, non-biodegradable heavy metal ions are the most prevalent. Thus, trace-level detection of these metal ions using a simple technique is essential. To address this issue, we have developed a fluorescent probe of Au/C nanodots (GCNDs-gold carbon nanodots) using an eco-friendly method based on an extract from waste onion leaves (Allium cepa-red onions). The leaves are rich in many flavonoids, playing a vital role in the formation of GCNDs. Transmission electron microscopy (TEM) and Scanning transmission electron microscopy-Energy-dispersive X-ray spectroscopy (STEM-EDS) elemental mapping clearly indicated that the newly synthesized materials are approximately 2 nm in size. The resulting GCNDs exhibited a strong orange fluorescence with excitation at 380 nm and emission at 610 nm. The GCNDs were applied as a fluorescent probe for the detection of Hg2+ ions. They can detect ultra-trace concentrations of Hg2+ with a detection limit of 1.3 nM. The X-ray photoelectron spectroscopy results facilitated the identification of a clear detection mechanism. We also used the new probe on a real river water sample. The newly developed sensor is highly stable with a strong fluorescent property and can be used for various applications such as in catalysis and biomedicine.


2019 ◽  
Vol 17 (4) ◽  
pp. 2043-2058
Author(s):  
S. Kakaei ◽  
E. S. Khameneh ◽  
M. H. Hosseini ◽  
M. M. Moharreri

Abstract The new clay modified with triazole and triazolium ligands was prepared in this research. These materials were applied as abundant and eco-friendly adsorbents for removal of heavy metal ions such as Pb(II), Co(II) and Zn(II) ions. The adsorption efficiency of these materials was calculated by relevant equations such as Langmuir and Freundlich as well as kinetic studies with pseudo-first-order and pseudo-second-order models. These adsorbents proved to be very active on heavy metal ion adsorption. The characterization of these new materials was carried out by various techniques such as X-ray diffraction, thermogravimetric analysis, scanning electron microscope (SEM), X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy as well as SEM-map analysis. Eventually, the catalytic activity of the adsorbents which treated with heavy metal ion solutions was studied in the reduction of nitroarenes to its corresponding amines. The prepared adsorbent–catalyst materials indicated efficient catalytic activity in the reduction of nitroarenes to amines in ambient conditions. Graphic abstract


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