Assay For Cu Research Articles

Synthesis, Spectral Characterisation and Pharmacological Studies on Co(II), Ni(II), Cu(II) and Zn(II) Bis-Schiff Base Complexes Derived From 4-hydroxybenzohydrazide

The transition metal(II) chelates were prepared by the reactions of bis-Schiff base ligands derived from 4-hydroxy benzohydrazide and isophthalaldehyde / o-phthaldehyde in 1:1 metal to ligand ratio. The formed ligands and their metal complexes have been investigated by the following spectroscopic tools i.e, elemental analysis, FT-IR spectra, molar conductance, 1H NMR, ESI-mass, electronic spectra, magnetic moments, ESR and thermal analyses. The low molar conductance values give the non- electrolytic nature of the metal(II) chelates. From that the spectroscopic observations of complexes having the molecular formula [M(Ln)2Cl2] (where M= Co(II), Ni(II), Cu(II) and Zn(II), n=1and 2) and act as tetradentate N2O2 donor sites of ligands. The docking results predicts that the protein with ligands having good interaction energy. All formed complexes have efficient antibacterial activity than ligand of tested pathogens. The mode of binding interaction of ct-DNA and Cu(II) complexes gives the intercalative binding with hypochromism shifts using electronic titrations method. In electrophoresis, cleavages of PUC18DNA to cleave effectively with Cu(II) complexes in the presence of hydroxyl radicals. The antioxidant assay of DPPH radical scavenging activity of tested compounds shows good results, when compared to ascorbic acid as standard. The anticancer MTT assay of Cu(II) complexes tested against MCF-7 cancerous cells gives the promising therapeutic activity.

Synthesis, spectral elucidation, antibacterial, antioxidant and DNA studies of ONNO tetradentate Schiff base metal(II) complexes derived from Benzene-1,4-dicarboxaldehyde

The new dibasic tetradentate (ONNO) Schiff base ligands (L1and L2) have been synthesized by the reaction of terephthalaldehyde with 2-amino 4-chlorophenol and X (where, X=2-amino 4-ethylphenol, 2-aminophenol) in 1:1:1 molar ratio. The macrocyclic binuclear Co(II), Ni(II) and Cu((II) metal complexes are prepared in ligand to metal ratio 2:2. The elements, metal structure and binding sites of Schiff bases and its complexes are established by diverse studies like elemental, molar conductance, UV, magnetic moment, FT-IR, H1 and C13 NMR, ESI-mass, ESR, thermal and powder-XRD. The spectral studies reveal that the ligands are tetradentate and its metal complexes possess a square planar geometry. All the compounds are screened for antibacterial, antioxidant and DNA cleavage and the results show high activity for metal complexes than the ligand. The DNA binding studies of Cu(II) complexes were measured by electronic absorption method. In vitro cytotoxicity assay of Cu(II) complexes have been tested for their tumour inhibiting potential against MCF-7 human breast cancer cell by using MTT method.

Design and Synthesis of Nanoencapsulation with a New Formulation of Fe@Au-CS-CU-FA NPs by Pulsed Laser Ablation in Liquid (PLAL) Method in Breast Cancer Therapy: In Vitro and In Vivo

The purpose of this study is to prepare nanoencapsulation synthesized with a new formulation of Fe@Au-CS-CU-FA nanoparticle (NPs) by pulsed laser ablation in liquid (PLAL) method as drug delivery to treat breast cancer (T-47D) and (MCF12A) as a normal cell line. The method synthesized Fe@Au NPs using the PLAL working at wavelength 532 nm with different laser fluence (1.9, 2.2, and 2.5) J/cm2. These Fe@Au NPs were characterized by atomic force microscope (AFM), field emission scanning electron microscopy (FESEM), and high-resolution transmission electron microscopy (HRTEM). The obtained mean sizes of Fe@Au NPs were 63.65, 32.47, and 31.18 nm at 1.9, 2.2, and 2.5 J/cm2, respectively. Results of the MTT assay of CU loaded Fe@Au-CS-FA NPs on human breast cancer cell line (T-47D) confirmed that cytotoxicity of CU can enhance when they are loaded on Fe@Au-CS-FA NPs in comparison with free CU. While results of flow cytometry showed that this combination can increase the therapeutic effects of CU by apoptosis induction in the T-47D cell line. Conclusion of Fe@Au-CS-CU-FA NPs causes a decrease in T-47D cell viability and caused induces 85% apoptosis. The in vivo study of Fe@Au-CS-CU-FA nanoformulation confirmed that the mean tumor size decreases in time.

Colorimetric and Fluorometric Paper-Based Assay for Cu2+ Detection Based on Green Synthesis of 2-Aminoterephthalic Acid-Derived Pigments.

In this study, we developed a simple and economical method for the green synthesis of Cu2+ sensors based on betaxanthin pigments. Aminoisophthalic acid-betaxanthin was synthesized by coupling 2-aminoisophthalic acid and betalamic acid produced from DOPA-extradiol-4,5-dioxygenase in situ and in vitro. The resulting 2-aminoterephthalic acid-betaxanthin (2-AIPA-BX) presented a satisfying fluorescence quantum yield in water and a high degree of selectivity for Cu2+ over interfering metal ions. The bioproduction process of 2-AIPA-BX was scaled up from test tubes to 1 L-flasks, indicating the robustness and reproducibility of this method. Additionally, we successfully incorporated 2-AIPA-BX into paper-based analytical devices to facilitate simple, inexpensive, and portable setup with lower sample consumption for onsite monitoring of environmental and biological samples.

Paper Based Assay of Copper (II) Ion Using Egg White as a Natural Chromogenic Reagent

A green analytical paper based assay of Cu (II) has been developed using egg white protein as a natural reagent. Either crayon and pencil graphite, or laser engraver may be used to effectively create hydrophobic barriers and hydrophilic reaction zones on the filter paper substrate. The reaction is observed via the Biuret test’s principle of Cu (II) ions reacting with nitrogen in the peptide bonds of the egg white under alkaline conditions to form a purple complex. Graphics editing software was used to determine the RGB values or grayscales of the reaction for the construction of a calibration graph. The volumes of reagents and samples were as low as 3 to 5 µL each. The limits of detection and limit of quantitation were determined to be 0.0002 M (0.04 µg Cu) and 0.0007 M (0.13 µg Cu), respectively. The main benefits of the proposed paper based assay compared to the use of a spectrophotometer are its ability to work with turbid reagents and samples and its portability. In addition, the color of egg white-Cu (II) complex is stable for a long period (at least two weeks) which allows flexible time for data analysis. This method has been shown to tolerate the presence of other ions, i.e., Al (III), Ca (II), Mg (II), and Zn (II) at concentrations at least 50 times of those of the analyte, and can tolerate the presence of Fe (II) up to the same concentration of Cu (II). The proposed paper based assay was demonstrated to successfully determine various Cu (II) salts in supplement samples.

Copper (I) Nicotinate complex Abrogates Acrylamide Induced Hepatotoxicity in Male Rats: Biochemical and Histological Studies

This study was conducted as a trail to abrogates acrylamide induced hepatotoxicity in male rats by administration of copper (I) nicotinic acid complex. Animals were divided into 4 groups ;GI: control kept on balanced diet and tap water , GII: Acrylamide group received acrylamide in drinking water (7.5 mg/kg b.w.) for 30 days. GIII: treated with copper (I)-nicotinate complex (400 μg/kg b.w.) after acrylamide intoxication for 30 days and GIV the complex then acrylamide (prophylactic). Results showed significant increase in serum levels of AST, ALT, ALP, GGT and total antioxidant capacity (TAC) in acrylamide group. Moreover a significant increase in tumer markers AFU and TNF-Alpha. while Levels of each of S. total protein and S. albumin were significantly decreased in ACR group compared with control. Histological study showed congestion of central vein in liver section and vacuolation of hepatocytes in ACR group. Anticancer activity using in-vitro cytotoxic assay of Cu (I) Nicotinate complex ; proves the anticancer properties of it comparing with doxorubicin. Treatment with Copper (I)-Nicotinate Complex restored tissue and serological indices concomitantly towards normal levels. These results revealed that Copper (I)-Nicotinate Complex is able to significantly alleviate the hepatotoxicity induced by AA in rats and could be utilized as a potent food additives.

An "off-on" colorimetric and fluorometric assay for Cu(II) based on the use of NaYF4:Yb(III),Er(III) upconversion nanoparticles functionalized with branched polyethylenimine.

The authors describe an "off-on" colorimetric and fluorometric assay for the determination of Cu(II). It is based on the use of upconversion nanoparticles (UCNPs) of type NaYF4:Yb(III),Er(III) that were functionalized with branched polyethylenimine (BPEI). A color change from colorless to blue occurs within 2s after addition of Cu(II) to a solution of the modified UCNPs. The color change can be visually detected at Cu(II) concentrations down to 80μM. The upconversion fluorescence of the modified UCNPs, measured at excitation wavelength of 980nm, is reduced due to the predominant inner filter effect caused by the formation of the BPEI-Cu(II) complex. Normalized fluorescence intensity drops linearly in the 50nM to 10μM Cu(II) concentration range, and the fluorometric detection limit is 45nM. Both the color and the fluorescence are recovered on addition of EDTA. Excellent selectivity over other metal ions and anions is achieved. Graphical abstract Upconversion nanoparticles of type NaYF4:Yb,Er werefunctionalized with branched polyethylenimine (UCNP/BPEI) and used in an "off-on" colorimetric and fluorometric assay for Cu(II). The upconversion fluorescence is selectively quenched on addition of Cu(II), and this isaccompanied by a rapid colorless-to-blue color switch. The colorimetric changes and quenched fluorescence canbe reversed by adding EDTA.

Synthesis of SPR Nanosensor using Gold Nanoparticles and its Application to Copper (II) Determination

This research describes a colorimetric assay for Cu (II) ions that is highly selective over other metal ions. It is based on the measurement of changes in the surface plasmon resonance absorbance (at 525 nm) of gold nanoparticles (Au NPs) modified with 1,7-diaza-15-crown-5 (Crown-Au NPs). The unique structure of crown ethers and presence of heteroatoms enable the crown-Au NPs to recognize very low concentrations of Cu (II) ions. After aggregation, the surface plasmon absorption band has a red shift so that the nanoparticle solution shows a violet color. The TEM images data show that this color change is a result of crown-Au NPs aggregation upon addition of Cu (II), In contrast, other metal ions Al3+, Ca2+, Cd2+, Co2+, Cr3+, Ag+, Fe2+, Fe3+, Hg2+, K+, Mg2+, Mn2+, Na+, Ni2+, Pb2+, and Zn2+ do not aggregate. The recognition mechanism is attributed to the formation of a sandwich (2+1) between the Cu (II) ion and two diaza-15-crown-5 moieties that are attached to separate nanoparticles. This simple and fast method can be used to determine the Cu (II) ions with a detection limit as low as 200 nM.

Heavy Metal Content On Sea Biota And Water At Estuary Region In East Coast South Kalimantan

Coal mining activity produces pollutant which is the coal dusts with heavy metals content. If the dusts mixed into the water, it will cause water pollution. Heavy metals like Pb, Zn, Cu, Cr needed by the living organisms, but if it exceeds the threshold, it will give negative impacts to the organism. Sea biota like mangrove snail (Telescopium telescopium) and mangrove crab (Scylla serrata) can be used as bio-indicators. This descriptive study aimed to determine the heavy metals content on sea bioata. Assays of Pb and Zn did on mangrove snail and assay of Cu and Cr did on mangrove crab. The heavy metals content in water performed as a comparison. There are three locations for sampling based on mangrove vegetation density which are high density, medium density, and low density. Heavy metals content test was done using Inductively Coupled Plasma (ICP) tool. Water quality standard based on South Kalimantan’s governor regulation (No. 5) 2007, and heavy metals content on sea biota based on Indonesia National Agency of Drug and Food Control (Balai POM) No 03725/B/SK/VII/1989. Specific for Cr based on Food and Drugs Administration (FDA). The results showed Cu accumulated over the threshold on mangrove crab in low density mangrove vegetation. Heavy metals content of Pb, Zn, and Cr on sea biota below the threshold. Heavy metals content on water also below the threshold. The study was conducted in physical environments that can be tolerated by sea biota.

Multimodal Plasmonic Assay of Copper(II) Ion via Stimuli-Responsive State Transformation of Silver Molecular Nanoparticles.

Molecular nanoparticles (MNPs) have gained increased attention recently due to their unique structures and properties. However, their applications remain largely unexplored. Herein, we present an Ag MNPs-based multimodal plasmonic assay. This assay relied on changes in optical properties due to stimuli-responsive state trans-formation from MNPs to plasmonic nanoparticles (PNPs). As a proof-of-concept, naked-eye colorimetric assay, spectrophotometric assay and "turn-on" Raman assay of Cu(2+) were developed. The feasibility of this approach for real-world applications was demonstrated with the determination of Cu(2+) in human serum. This multimodal plasmonic assay exhibited several significant advantages, including selectivity, sensitivity, label-free nature, and multimodal capability. Because of these merits, Ag MNPs could be promising nanosensors for wide important applications such as diagnostics and environmental analysis.

Pattern recognition of Cu(II), Pb(II), Hg(II), and Cd(II) in waste waters

Pattern recognition of Cu(II), Pb(II), Hg(II) and Cd(II) in waste waters collected from a mining area, was performed using a fast screening method based on a new stochastic sensor. The stochastic sensor is based on physical immobilization of N,Nź-ethylenebis[N-[(3-(pyrrole-1-yl)propyl) carbamoyl) methyl]-glycine]) in diamond paste. The limits of determination of the cations were as low as 10 pmol/L [for the assay of Cd(II)], and 100 pmol/L [for the assay of Cu(II), Hg(II), and Pb(II)]. The cations were determined from the waste water samples without any pretreatment of the water samples, within 20 min with recoveries higher than 98.80 %, and low RSD (%) values.

Biocompatible glutathione-capped gold nanoclusters for dual fluorescent sensing and imaging of copper(II) and temperature in human cells and bacterial cells

Highly red luminescent gold nanoclusters (AuNCs) have been prepared at physiological temperature by using glutathione (GSH) as a stabilizing and capping agent in aqueous media. The resultant AuNCs have been characterized by photoluminescence and X-ray photoelectron spectroscopy, transmission electron microscopy and FTIR. The AuNCs exhibit red fluorescence with a quantum yield of 3.1 %, and fluorescence is strongly quenched by copper(II) ion due to aggregation. This finding is exploited in a fluorometric assay for Cu(II) that has a 2.8 nM detection limit. The method was applied to the determination of Cu(II) ion in (spiked) mineral water and Tai Lake water. In addition, the AuNCs display a strongly temperature-dependent emission that can be used for optical determination of temperature in the 0 to 60 °C range. We finally show that the AuNCs are viable nanomaterials for (a) plain imaging of Hep-2 cells by laser scanning confocal microscopy, and for (b) intracellular imaging of Cu(II) and of temperature in Hep-2 cells and E. coli.

An improved Bathocuproine assay for accurate valence identification and quantification of copper bound by biomolecules

Copper is an essential metal in all organisms. Reliably quantifying and identifying the copper content and oxidation state is crucial, since the information is essential to understanding protein structure and function. Chromophoric ligands, such as Bathocuproine (BC) and its water-soluble analog, Bathocuproinedisulfonic acid (BCS), preferentially bind Cu(I) over Cu(II), and therefore have been widely used as optical probes to determine the oxidation state of copper bound by biomolecules. However, the BCS assay is commonly misused, leading to erroneous conclusions regarding the role of copper in biological processes. By measuring the redox potential of Cu(II)-BCS2 and conducting UV–vis absorption measurements in the presence of oxidizable amino acids, the thermodynamic origin of the potential artifacts becomes evident. The BCS assay was improved by introducing a strong Cu(II) chelator EDTA prior to the addition of BCS to prevent interference that might arise from Cu(II) present in the sample. The strong Cu(II) chelator rids of all the potential errors inherent in the conventional BCS assay. Applications of the improved assay to peptides and protein containing oxidizable amino acid residues confirm that free Cu(II) no longer leads to artifacts, thereby resolving issues related to this persistently misused colorimetric assay of Cu(I) in biological systems.

Multi‐element stable isotopic dilution and multi‐surface modelling to assess the speciation and reactivity of cadmium and copper in soil

SummaryChemical extraction, multi‐element stable isotopic dilution (ID) and multi‐surface modelling were used to investigate the lability of cadmium (Cd) and copper (Cu) in nine types of soil with different properties and contaminated or not with Cd and Cu. The chemical extraction and ID analyses both showed that Cd was more labile than Cu in all the soil types studied. From the ID results, 32.8–93.3% of total Cd and 14.7–71.8% of total Cu were isotopically exchangeable after 3 days of equilibration. A single extraction in 0.43 m HNO3 gave similar results to the 3‐day ID assay for Cu in most of the soils and for Cd in the non‐calcareous soils. However, an eight‐step selective sequential extraction (SSE) procedure gave different results from the ID assay for both metals. Predictions of the multi‐surface model for the amounts of Cd and Cu adsorbed, based on measured metal ion activities in the soil solution and the concentrations of reactive surfaces in the soil, agreed with the ID results. The model predicted that soil organic matter was the predominant sorbent for Cd and Cu in the soils and that manganese oxide was the least important sorbent. The contributions of iron oxides to sorption were predicted to be small except in soil with a high pH and little organic matter. The predicted sorption on different soil components did not match SSE measurements.

A colorimetric and luminescent dual-modal assay for Cu(II) ion detection using an iridium(III) complex.

A novel iridium(III) complex-based chemosensor bearing the 5,6-bis(salicylideneimino)-1,10-phenanthroline ligand receptor was developed, which exhibited a highly sensitive and selective color change from colorless to yellow and a visible turn-off luminescence response upon the addition of Cu(II) ions. The interactions of this iridium(III) complex with Cu2+ ions and thirteen other cations have been investigated by UV-Vis absorption titration, emission titration, and 1H NMR titration.

Enzymatic Assay for Cu(II) with Horseradish Peroxidase and Its Application in Colorimetric Logic Gate

We report an ultrasensitive and colorimetric assay for Cu(II) via enzymatic amplification strategy. The enzymatic activity of horseradish peroxidase (HRP) is strongly inhibited by Cu(I), which can be used indirectly to assay Cu(II). The limit of detection (LOD) is 0.37 nM, and the detection of 20 nM Cu(II) in solution can be achieved with naked eyes. This assay can be used to construct a colorimetric logic gate.

Visual test of subparts per billion-level copper(ii) by Fe3O4 magnetic nanoparticle-based solid phase extraction coupled with a functionalized gold nanoparticle probe

By combining Fe(3)O(4) magnetic nanoparticle-based solid phase extraction with a gold nanoparticle-based visual test, a novel method was developed for the field assay of Cu(ii) in environmental water at subparts per billion-levels within 30 min. When a 200 mL water sample was treated with 12.5 mg L(-1) Fe(3)O(4) nanoparticles by the proposed procedure, the detection limit with the naked eye was 0.2 μg L(-1) Cu(ii). The proposed method is very specific to Cu(ii), with tolerance against at least 100-fold amounts of other environmentally relevant metal ions except for Hg(ii) (25-fold), and was successfully applied to the detection of trace Cu(ii) in tap water, river water, and treated wastewater, and results agreed well with that determined by inductively coupled plasma-mass spectrometry (ICP-MS).

Two-photon excited fluorescent chemosensor for homogeneous determination of copper(ii) in aqueous media and complicated biological matrix

In the present work, a two-photon excited fluorescent chemosensor for Cu(2+) was prepared. The probe was constructed on the basis of internal charge transfer (ICT) principle with macrocyclic dioxotetraamine as the Cu(2+) receptor. The good water-solubility of the molecule enabled recognition and assay of Cu(2+) ions in biological media. The photophysical properties of the chemosensor were investigated in detail, exhibiting favorable fluorescence quantum yield and moderate two-photon absorption cross-section. The studies on binding thermodynamics demonstrated the formation of 1 : 1 complex between the chemosensor and Cu(2+) and an association constant of ca. 1.04 × 10(5) M(-1). Due to the rational design of the molecular structure, the sensor was highly specific to Cu(2+), which ensured high selectivity in Cu(2+) determination. Upon Cu(2+) binding, the intramolecular charge-transfer extent within the chromophore was weakened resulting in a remarkable quenching of fluorescence, based on which quantitative determination of Cu(2+) was performed. Good linearity was obtained between the fluorescence quenching value and Cu(2+) concentration ranging from 0.04 to 2.0 μM in aqueous solution. Benefiting from the merits of two-photon excitation, the chemosensor was free of interference from background luminescence in serum. A homogeneous quantitative determination of Cu(2+) was achieved in the serum medium with a linear range of 0.04 to 2.0 μM. Considering the structural flexibility of the sensor, this work also opens up the possibility to construct other two-photon excited chemosensors for direct homogeneous assay of various molecules/ions in complicated biological sample matrices.

Diagnosis of copper ions in vascular tracts using a fluorine-doped carbon nanotube sensor

The voltammetric assay of Cu(II) was investigated using a carbon nanotube electrode (CNE) and fluorine immobilized onto a carbon nanotube electrode (FCNE) in cyclic voltammetry (CV), square-wave (SW) stripping voltammetry, and chronoamperometry. Optimum SW conditions were attained at working ranges of 0.01–0.11 ng L −1 Cu(II) (11 points), and a relative standard deviation of 1.68% (RSD, n = 15) was observed at 10.0 μg L −1 Cu(II). Within a 200 s accumulation time, detection limit of 0.006 μg L −1 was attained. The life span of each electrode was more than 1 month. The sensor was applied to tap water, blood, and rat tail vascular (in vivo). It was found that the sensor could be used with an interface system in the assay of live cells and non-treated blood.

Serum superoxide dismutase 3 (extracellular superoxide dismutase) activity is a sensitive indicator of Cu status in rats

Sensitivity of the assay for Cu,Zn superoxide dismutase 3 (SOD3), the predominant form of SOD in serum, can be increased, and interferences caused by low-molecular-weight substances in the serum can be reduced by conducting the assay at pH 10 with xanthine/xanthine oxidase and acetylated cytochrome c (cyt c) as superoxide generator and detector, respectively. Serum SOD3 activity was assayed under these conditions in an experiment where weanling, male rats were fed diets for 6 weeks containing 3, 5 and 15 mg Zn/kg with dietary Cu set at 0.3, 1.5 and 5 mg Cu/kg at each level of dietary Zn. Serum SOD3 responded to changes in dietary Cu but not to changes in dietary Zn. A second experiment compared serum SOD3 activity to traditional indices of Cu status in weanling, male and female rats after they were fed diets containing, nominally, 0, 1, 1.5, 2, 2.5, 3 and 6 mg Cu/kg for 6 weeks. Serum SOD3 activity was significantly lower ( P<.05) in male rats fed diets containing 0 and 1 mg Cu/kg and female rats fed diet containing 0 mg Cu/kg compared with rats fed diet containing 6 mg Cu/kg. These changes were similar to changes in liver Cu concentrations, liver cyt c oxidase (CCO) activity and plasma ceruloplasmin in males and females. Serum SOD3 activity was also strongly, positively correlated with liver Cu concentrations over the entire range of dietary Cu concentrations ( R 2=.942 in males, R 2=.884 in females, P<.0001). Plots of serum SOD3 activity, liver Cu concentration, liver CCO activity and ceruloplasmin as functions of kidney Cu concentration all had two linear segments that intersected at similar kidney Cu concentrations (18–22 μg/g dry kidney in males, 15–17 μg/g dry kidney in females). These findings indicate that serum SOD3 activity is a sensitive index of Cu status.