Chelating Effect Research Articles

In-Vitro Antioxidant Activity and Total Phenolic Content of Ruta montana L. Extracts

The aim of this study is to evaluate in vitro antioxidant activities of Ruta montana L. extracts. This activity was evaluated by three methods : DPPH (2, 2'-diphenyl- 1- picrylhydrazy), bleaching of β-carotene and chelation of ferrous iron. Results showed that ethyl acetate extract (EAE) represents the highest amount of total polyphenols, tannins and flavonoids with 257,1 ± 0,703µg gallic acid equivalent/mg of extract, 251 ± 1.41 µg tannic acid equivalent /mg of extract,117,4 ± 3,451 µg quercetin equivalents/mg of extract, 139,5 ± 4,107 µg rutin equivalents/mg of extract, respectively. In the DPPH assay, ethyl acetate extract showed the higher scavenging capacity (IC50 = 0.044 ± 0.001 mg/ml) followed by methanol, aqueous and chloroform extract. Whereas, AqE showed the best chelating effect and the best inhibitory capacity of the coupled oxidation of linoleic acid/ β-carotene.
 Keywords: Ruta montana L; polyphenols; antioxidant activity; free radical scavenging.

Function Synergy of Cross-Linked Cationic PVA Polymer to AMPS-Type Fluid Loss Additive Used for Cement-Based Material

In this research, a kind of 2-acrylamido-2-methylpropanesulfonic acid sodium salt- (AMPS-Na-) type copolymer additive, the fluid loss additive (FLA), named as FLA A additive, was used for research. The performance of FLA A was tested and found to fail in the effective control of free water and to hinder the hydration process for delaying the breaking of the early hydration shell. The reason for it was the absorbed behavior and chelating effect of the AMPS-Na unit to Ca2+ hydrating cement particles. Thus, a cationic polyvinyl alcohol (PVA) polymer, modified by glyoxal and boric acid, was discovered due to its excellence in associating with the FLA A additive for controlling the free cement-based material water amount and preventing the chelating effect of FLA A chains on the surface of the cement-based material. Glyoxal/boric acid-modified polyvinyl alcohol, abbreviated as PVAGB or PVA-G-B, was with special molecular properties, i.e., positive ZETA (ζ) potential characteristics and cross-linked molecular structure. Due to competitive absorbed behavior of glyoxal-modified hydroxyl groups and free Ca2+ released by the hydration product, the chelating effect of AMPS-Na units to Ca2+ was weakened and the possibility of FLA A chains being absorbed to the surface of the cement-based material was decreased. Then, the formation of a complete fluid loss system was obtained; i.e., the fluid loss volume decreased to less than 50 mL at 30°C and 108 mL at 80°C with 0.2 percentage by weight of cement (%BWOC) of PVAGB and 0.50%BWOC (percentage by weight of cement) of FLA A. Besides, the hydration process of cement-based material was accelerated due to formation of more C-S-H gels in the early hydration period. As a result, the cement-based material not only showed no worse compressive-strength retrogression but also showed a stable 28-day compressive strength of 28 MPa.

Evaluation of chelating and cytoprotective activity of vanillin against the toxic action of mercuric chloride as an alternative for phytoremediation.

Mercury is widely found in nature, however, in low concentrations, but anthropological activities have increased its concentration considerably. This causes various environmental hazards and human health. Many substances are capable of reversing the toxicity of mercuric chloride in the environment. The aim of the present study was to determine the chelating effect of vanillin, as well as to evaluate its capacity for cytoprotection in prokaryotic and eukaryotic plant models. Chelating activity was determined from vanillin's ability to reduce iron III ions. To evaluate cytoprotection in a unicellular prokaryotic and eukaryotic model, Escherichia coli and Candida albicans, respectively, were used. And to evaluate the cytoprotective activity in vegetables, lettuce seeds were submitted to different concentrations of mercuric chloride and its association with the sub-allelopathic concentration of vanillin (32µg/mL). Vanillin has been found to have antioxidant activity as it can reduce iron III ions. The use of vanillin also allows for better growth and development of Lactuca sativa seed root and stem, also allowing better preservation of its biochemical structures. These results are quite important, as environmental contamination by heavy metals has increased dramatically and finding a viable alternative to grow vegetables in contaminated areas is very valid.

Surface modification of titanium implants by ZIF-8@Levo/LBL coating for inhibition of bacterial-associated infection and enhancement of in vivo osseointegration

Bone implant-associated infection is one of the major concerns in orthopedics, and may even result in implant failure. To this end, we developed a strategy for the fabrication of an antibacterial coating on titanium (Ti) implants with pH-response to combat bacteria-mediated acidification of the local microenvironment. It includes three steps: first, we synthesized levofloxacin (Levo)-loaded zeolitic imidazolate framework-8 (ZIF-8@Levo) nanoparticles; second, the nanoparticles were loaded onto the collagen-modified Ti substrates by the cathode electrophoresis deposition (EPD) method; third, gelatin (Gel) and chitosan (Chi) multilayers were spin-coated on the modified Ti substrates, since the chelating effect of Gel and Chi would reduce the hydrolysis of ZIF-8@Levo for a sustained release of Levo and Zn2+. The fabricated samples of MOF@Levo/LBL promoted in vitro adhesion, proliferation, and differentiation of osteoblasts. Moreover, the MOF@Levo/LBL samples exhibited strong antibacterial ability against Escherichia coli and Staphylococcus aureus through hydrolysis of ZIF-8 nanoparticles, thereby creating a marginally alkaline microenvironment. Furthermore, in vivo implantation in a femur-infected rat model revealed that MOF@Levo/LBL implants effectively inhibited bacterial adhesion, apart from significantly improving osseointegration of the Ti implants. The study provides a promising alternative for fabricating multifunctional Ti implants with strong antibacterial capacity and enhanced bone formation for potential orthopedic application.

Effect of different molecular weight on the antioxidant activity and physicochemical properties of golden apple snail (Ampullariidae) protein hydrolysates

Golden apple snail (GAS) is reported to have a medicine effect for treat broken bones, back pain and stool bloody. This study was aimed to investigate the fractionation of protein hydrolysate from the golden apple snail (GAS) using an ultrafiltration technique with molecular weight cut-offs of 3, 5, and 10 kDa, followed by the determination of its antioxidant activity and functional properties. In terms of antioxidant activity, fraction of 3 kDa showed the highest reducing power and DPPH radical scavenging activity. Additionally, fraction of 5 kDa had the highest chelating effect on ferrous ion (85.6%). The results also revealed that fraction of 3 kDa showed good emulsion activity index and water binding capacity, while 5 kDa showed good foaming capacity and solubility. These results suggested that GASH showed potential for application in the food industry as its antioxidant, with strong functional properties able to be obtained by varying its molecular weights.

Quantum chemical investigation of the oxidative addition reaction of allyl carboxylates to Ni(0) and Pd(0) complexes

Objectives. The first allylpalladium complex was synthesized and characterized 60 years ago at the Department of Physical Chemistry of M.V. Lomonosov Moscow State University of Fine Chemical Technology (MITHT). This discovery was an important stage in the development of a new direction in chemistry - metal complex catalysis, which subsequently led to understanding the strategy for studying the mechanisms of catalysts action, and gave a powerful impetus to the study of intermediates of catalytic reactions. The key sta.ge in many catalytic processes involving transition metal complexes is the oxidative addition stage. The study’s aim was the quantum chemical modeling of the oxidative addition stage of allylic carboxylates to the Ni(0) and Pd(0) complexes. Methods. Quantum chemical calculations were carried out under the Kohn-Sham method for the density Junctional theory using the PBE exchange-correlation Junctional and all-electron L11 basis set. Results. As a result of theoretical study, we showed that the oxidative addition of allyl acetate to the triisopropylphosphite complex of nickel(0) and allyl formate to the triphenylphosphine complex of palladium(O) can proceed along two routes. In the first of them, in the coordinated breaking of the С - О bond and the formation of the metal-O bond, the same oxygen atom is involved, thus forming a three-center transition state. In the second route, the restructuring of relations is carried out in a five-center transition state. The chelating effect in the five-centered transition state of the second route reduces the reaction’s activation barrier by 12.7 kcal/mol for allyl acetate and the nickel(0) triisopropylphosphite complex Ni(P(QPr) 3 ) 2 and by 9.9 kcal/mol for allyl formate and the palladium(O) triphenylphosphine complex Pd(PPh 3 ). The presence of the second triphenylphosphine ligand in Pd(PPh 3 ) 2 reduces the activation barrier by only 2.6 kcal/mol. Conclusions. The quantum chemical modeling performed allowed us to determine the preference for the oxidative addition of allyl carboxylates to the Ni(0) and Pd(0) complexes through a five-center transition state. The reaction’s activation barriers through the “classical” three-center interaction are 9.9-12.7 kcal/mol higher, and the chelating effect is more noticeable for the Ni complex The presence in the coordination sphere of several bulky ligands, such as triphenylphosphine, practically eliminates the chelating effect in the oxidative addition of allyl carboxylates.

In-Situ Growth of Broussonetia-Like NiCo₂O₄ on Carbon Cloth with Tailored Aqueous Capacitance.

Tailored broussonetia-like NiCo₂O₄ is grown on carbon cloth using tri-sodium citrate assisted hydrothermal method. The chelating effect of citric ions has been utilized to investigate the morphological and structural evolution of NiCo₂O₄ on carbon cloth, which have been illustrated by scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectra. The results demonstrate that the morphological alteration of NiCo₂O₄ from single nanowire to broussonetia-like structure has been detected after the addition of tri-sodium citrate. Citric ion plays a crucial role as an electrostatic stabilizer in determining this unique structure. When used as binder-free electrode in aqueous supercapacitors, the broussonetia-like NiCo₂O₄ electrode exhibits a specific capacitance of 527.9 F g-1 at a current density of 0.5 A g-1. Additionally, an asymmetric supercapacitor is further assembled using NiCo₂O₄ as the positive electrode and activated carbon as negative electrode. The device exhibits a maximum energy of 26.4 Wh kg-1 at power density of 800 W kg-1. A long-term cycling stability with 82% capacitance retention is maintained after 20,000 cycles at a current density of 5 A g-1, indicating the practical applicability of the tested device.

High‐electromagnetic‐shielding cotton fabric prepared using multiwall carbon nanotubes/nickel–phosphorus electroless plating

High‐electromagnetic‐shielding cotton fabric (CF) was prepared using carboxyl‐functionalized multiwall carbon nanotubes (MWCNTs‐COOH)/nickel–phosphorus (Ni‐P) electroless plating. Firstly, MWCNTs‐COOH was loaded on CF used to chelate the metal catalyst followed by electroless plating to impart outstanding electrical conductivity and electromagnetic shielding properties. The intermediate MWCNTs‐COOH layer not only improves the bonding strength via the chelating effect, but also can be used as a conductive material. This synergistic action of MWCNTs‐COOH and Ni‐P layer can work together to improve the electromagnetic interference shielding performance. The features of Ni‐P/MWCNTs‐COOH/CF were characterized using scanning electron microscopy, energy‐dispersive spectroscopy, X‐ray photoelectron spectroscopy and X‐ray diffraction. The resulting Ni‐P/MWCNTs‐COOH/CF fabrics show high surface resistance of 1.66 Ω sq−1 and robust electromagnetic shielding effectiveness of 40.2 dB. Furthermore, benefiting from the strong interface interaction, the as‐prepared composite fabrics retain stable performances after undergoing a series of physical and chemical tests, confirming promising practical applications even under harsh conditions.

Therapeutic potential of dithiocarbamate supported gold compounds.

Chrysotherapy or aurotherapy, the use of gold as medicine, is two thousand years old. Hitherto, numerous diverse gold stabilizing ligands for instance vitamins, pyridine, phosphines, naphthylamine and xanthanes have been developed and their ‘chelating effect’ in addition to their anti-proliferative properties have been extensively studied. Recent advances in the field of bioinorganic chemistry have led to the design of biologically relevant metal complexes with appropriate fine-tuned ligands such as metallic conjugates of dithiocarbamates (DTCs). DTC compounds have been recognised to possess diverse applications and have demonstrated interesting biological properties. For instance, the chemoprotective and antitumour properties of gold metal ions and DTC compounds respectively, presents an innovative and effective approach to cancer management. This review presents therefore the therapeutic potential of DTC ligand systems as a support for gold compounds. The importance of dithiocarbamate supported gold compounds as potential therapeutic agents is highlighted with emphasis on the therapeutic potential of gold(iii) and gold(i) dithiocarbamate derivatives.

Medicinal Properties of Clitocybe brunneocaperata (Agaricomycetes) from India.

The present research documented the first evidence of Clitocybe brunneocaperata from Tripura, Northeast India. The main purposes of this study were identification of the mushroom and qualitative toxicity screening along with antibacterial and antioxidant activities of its methanolic extracts. The species has been recognized on the basis of the morphometric and molecular studies. Toxicity test revealed its inedibility nature. Methanolic extracts of C. brunneocaperata showed potent antibacterial, free radical scavenging effect (65.42%), chelating effects on ferrous ion (65.93%), total phenolic content (0.028 mg GAE/g), and flavonoid content (0.013 mg CE/g). The lowest EC50 values of the free radical scavenging effect (5.94 mg/ml) and chelating effects on ferrous ion (0.072 mg/ml) were observed at 16 and 1.5 mg/ml concentrations, respectively, which implied stronger capability of free radical scavenging. Therefore, further research is also required to isolate and characterize the principal components of C. brunneocaperata.

Ultra-efficient and stable heterogeneous iron-based Fenton nanocatalysts for degrading organic dyes at neutral pH via a chelating effect under nanoconfinement.

An ultra-efficient and stable heterogeneous iron-based Fenton nanocatalyst has been developed for degrading organic dyes at neutral pH via a chelating effect under nanoconfinement. The catalyst demonstrates an exceptionally high degradation capacity of 2600 mg g-1 for methylene blue and rapid degradation efficiencies at neutral and basic conditions. Moreover, MPOPs are highly stable and recyclable without any obvious performance loss and iron leaching under different pH conditions.

Phytochemical profiles and anti-diabetic benefits of two edible Amaranthus species

ABSTRACT Phytochemical profile and activity of anti-oxidative, anti-glycative, anti-α-amylase, anti-α-glucosidase, anti-lipase and anti-acetylcholinesterase (AchE) of aqueous extracts prepared from leaf and stem parts of two edible Amaranthus species, white and red amaranths, were investigated. Phytochemical analyses showed that white amaranth had more total phenolic acids than red one. The content of total flavonoids in four examined aqueous extracts was similar. Red amaranth has greater anthocyanins and carotenoids than white one. All aqueous extracts at three concentrations were used for in vitro bio-activities experiments. Results showed that four aqueous extracts displayed radical scavenging effect, Fe2+ chelating effect, xanthine oxidase inhibition, and reducing power. Aqueous extracts prepared from red amaranth exhibited marked anti-glycative effects, anti-α-amylase, anti-α-glucosidase, anti-lipase, and anti-AchE activities. These findings suggested that these two vegetables could be developed as functional foods for diabetic prevention and/or attenuation.

Stable mixed-valence diphenylphosphanido bridged platinum(ii)-platinum(iv) complexes.

The reaction between [NnBu4][(C6F5)2PtII(μ-PPh2)2PtIV(C^N)(I)2] (C^N = κ2-N,C-benzoquinolinate, 1) and (i) bidentate S^S, N^S and O^O anionic ligands or (ii) monodentate S- N- or O-based anionic ligands was studied in order to investigate the factors that may guarantee the stability of Pt(ii),Pt(iv) mixed-valence dinuclear phosphanido complexes. While reactions of 1 with S^S or N^S ligands afforded stable Pt(ii),Pt(iv) species of general formula [(C6F5)2PtII(μ-PPh2)2PtIV(C^N)(L^S)]x- [(L^S)(x-1) = 2-mercaptopyrimidinate (pymS-), 2-mercaptopyridinate (pyS-), dimethyldithiocarbamate (Me2NCS2-), ethyl xanthogenate (EtOCS2-) and 1,2-benzenedithiolate (PhS22-)], the reaction of 1 with the O^O ligand sodium acetylacetonate gave several products, and no pure Pt(ii),Pt(iv) complex could be isolated. The reaction of monodentate ligands such as PhS-, OH- or N3- with 1 led to a stable Pt(ii),Pt(iv) complex only in the case of N3-. The reaction with OH- afforded the Pt(ii),Pt(ii) complex [(C6F5)2PtII(μ-PPh2)(κ2-O,P-μ-O-PPh2)PtII(C^N)]- (8) deriving from reductive coupling of a diphenylphosphanide and an O-donor ligand coordinated to the Pt(iv) centre, while the reaction with PhS- produced the unstable Pt(ii),Pt(iv) complex [NnBu4][(C6F5)2PtII(μ-PPh2)2PtIV(C^N)(PhS)2] (11) that evolved in solution to the Pt(ii),Pt(ii) species [NnBu4][(C6F5)2PtII(μ-PPh2)2PtII(C^N)] (9) by elimination of diphenyldisulfide. Thus, the stability of mixed valence Pt(ii),Pt(iv) phosphanide complexes is affected by several concurrent factors, including the chelating effect of the ligands and the type of ligating atoms.

Formation of iron(iii)–thiolate metallocyclophane using a ferrocene-based bis-isocyanide

Ferrocene-based iron–thiolate complexes are reported, and the kinetic product transforms to its corresponding thermodynamic product by the chelating effect of Fc(NC)2.

Morphological Characteristics, Molecular Identification and Antioxidant Activities of Phallus atrovolvatus (Agaricomycetes) Isolated from Thailand.

Phallus atrovolvatus is a wild edible mushroom found in Thailand. Three strains of Ph. atrovolvatus (DOAP-1, DOAP-2, and DOAP-3) were collected from forests in Central Thailand. Some requirements for mycelial growth were obtained in different media. Potato dextrose agar was determined as the best medium to support mycelial growth (83.50 mm after incubation for 7 days). Molecular phylogenetic analyses based on the sequence of internal transcribed spacers (ITS1 and ITS4) confirmed DOAP-1 species status within Phallaceae as Ph. atrovolvatus with high levels of similarity at 99.34%. Antioxidant properties of hot water extract from the fruiting body of three isolates (CMP-1, CMP-2, and CMP-3) were also evaluated. Highest free radical scavenging ability was found in CMP-1 (94.94% at 2.0 mg/mL) whereas crude mushroom extracts exhibited very strong ferrous-ion chelating effects of 99.16% at 10 mg/ mL. Results indicating that all CMP isolates from Ph. atrovolvatus possess excellent antioxidant properties from natural sources.

Antioxidant and antityrosinase activities of milky white mushroom

It was intended to investigate the biological activities of different solvent extracts of the fruiting bodies of Calocybe indica (P & C). The bioactive compounds were extracted using acetone, methanol, and hot water. The antioxidant activities of three different extracts at 0.5-20.0 mg/ml of C. indica on β-carotene-linoleic acid ranged from 65.83 - 92.56, 62.79 - 93.06 and 61.42 - 92.12%, respectively. The highest (2.825) reducing power inhibition was recorded in methanolic extract, while the lowest (2.332) was in hot water at the concentration of 8 mg/ml. The free radicle scavenging activity was more pronounced in methanolic extract. Chelating effect of C. indica was significantly strong as compared to positive control. The xanthine oxidase and tyrosinase inhibitory activity of the acetone, methanol, and hot water extracts of C. indica increased with increasing concentration. Thirteen phenolic compounds i.e. biochanin-A, caffeic acid, chlorogenic acid, ferulic acid, formononetin, gallic acid, hesperetin, homogentisic acid, naringenin, naringin, protocatechuic acid, resveratrol and vanillin were detected from acetonitrile-hydrochloric acid extract. The result indicated that the maximum and minimum concentrations were recorded for gallic acid (29 μg/g) and formononetin (10 μg/g). Thus, it could be suggested that C. indica has the potential to be used as antioxidant and tyrosinase protection system of the human body against oxidative damage and other complications.

Mechanism on releasing and solubilizing of fish bone calcium during nano‐milling

AbstractFish bone, predominately composited by collagen and hydroxyapatite (HAP), is a natural calcium resource that possesses the potential to be used as functional ingredient in food application. In this study, five HAP suspensions with either collagen or amino acids were applied to simulate the releasing and solubilizing of fish bone calcium during nano‐milling. As milling time was increased, particle sizes from five suspensions gradually decreased and pH increased. The sizes and pH kept constant as the time was extended beyond 60 min (p < .05). Initial soluble calcium content of HAP suspension fluctuated with milling time and was not increased after milling for 240 min. However, soluble calcium contents of HAP suspensions with collagen and amino acids continuously increased and reached the highest values of 106.70 and 147.34–645.68 μg/g, respectively. After nano‐milling, crystallinity of HAP particles declined and calcium element on the surface decreased and contents of free amino acid and peptides from fish bone suspension significantly increased (p < .05). Our results suggested that the releasing and solubilizing of fish bone calcium during nano‐milling was mainly attributed to alterations on size and crystalline structure of HAP, and the chelating effects by amino acids and peptides.Practical ApplicationsFish bone is the main solid waste from fish processing industry. When properly processed, it possesses the potential to be used as food grade calcium additive. It has been reported that grittiness of fish bone could be neglected after reducing its particle to nanoscale. Furthermore, soluble calcium content was significantly increased, which might be benefit for improving calcium bioavailability of fish bone. However, there is no report regarding the release of calcium from fish bone during nano‐milling process so far. This research will provide scientific foundation for improving solubility of calcium from various natural resources in a physical method.

Effect of PAAT as an Environmentally Friendly Terpolymer on the Scale Inhibition of CaCO3 in Artificial Seawater: Chemical and Electrochemical Study

The inhibition behavior of poly(acrylic acid:2-acrylamido-2-methylpropanesulfonic acid:tert-butyl acrylamide) (PAAT) as an environmentally friendly terpolymer on the calcium carbonate scaling in artificial seawater was investigated using electrochemical and chemical screening methods. Therefore, the inhibition mechanism of PAAT was attributed to both threshold and chelating effect. However, the threshold effect had a higher contribution to the inhibition of CaCO3 scaling rather than the chelating effect. The greatest inhibition efficiency of PAAT was achieved at 2 ppm concentration. These results were confirmed by surface analysis methods including scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Moreover, the chronoamperometry test revealed that PAAT has a better inhibition performance than both homopolymer poly(acrylic acid) and copolymer poly(acrylic acid:2-acrylamido-2-methylpropanesulfonic acid).

Corrosion protection mechanism of aluminum triphosphate modified by organic acids as a rust converter

Water-borne rust-resistant coatings were prepared by using aluminum triphosphate as the rust conversion agent and a styrene acrylic emulsion, and the mechanism of rust prevention was studied by electrochemical impedance spectroscopy. With increasing soaking time, aluminum triphosphate is further decomposed into orthophosphate to improve the corrosion resistance of the matrix. Within six hours, with increasing immersion time, the impedance value of the conversion film increased, and the maximum impedance of the conversion coating was 954.4 Ω cm2, indicating that the speed of rust transformation to form a protective film was slow and that the corrosion resistance of the conversion film was low. Hydroxyethylidene-1,1-diphosphonic acid (HEDP) and tannic acid were added to modify aluminum triphosphate, and all of them had a chelating effect. Through synergistic effects, the impedance of the modified conversion film reaches 32,495 Ω cm2, which improves the rust conversion and antirust performance and obviously improves the shortcomings of the early antirust performance of aluminum triphosphate used alone. The results of infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy show that the modification with the organic acids involves adsorption on the aluminum triphosphate particles through physical and chemical adsorption. Electrostatic repulsion can prevent the tripolyphosphate ions from agglomerating, making them uniformly dispersed and improving the bonding of the coating film. The modified formulation has better corrosion resistance and rust transformation ability than that of aluminum triphosphate alone.

Novel anionic polyacrylamide-modify-chitosan magnetic composite nanoparticles with excellent adsorption capacity for cationic dyes and pH-independent adsorption capability for metal ions

Abstract Wastewater containing highly toxic, non-biodegradable and carcinogenic organic dyes and metal ions has been regarded as a severe threat to ecological environment and human health. Thus, it is of great significance to develop an effective approach to purify this kind of wastewater. Herein, novel magnetic adsorbent FS@CS-PAA was facilely prepared by coating anionic polyacrylamide-modified chitosan (CS-PAA) on the surface of silica-combined Fe3O4 (FS). The morphology, structure, physic-chemical and magnetic properties of as-prepared FS@CS-PAA were fully characterized by various characterization techniques. Its adsorption behaviors towards cationic dyes and metal ions were systematically investigated in single systems, binary systems, and model wastewater. FS@CS-PAA was proved to have superior adsorption capacities of 2330.17 and 1044.06 mg g−1 respectively for crystal violet and methylene blue at 318.15 K, much higher than other reported adsorbents. Besides, FS@CS-PAA exhibited a pH-independent adsorption capability for metal ions, as demonstrated in single systems and in metal ion-dye binary systems, thus it could be used to treat a variety of metal ion wastewaters with different pH values. Moreover, FS@CS-PAA could be effectively and easily regenerated by HCl solution after the treatments of both synthetic wastewater and model wastewater. As revealed in FTIR and XPS analyses, the adsorption mechanism was mainly attributed to the electrostatic interaction, hydrogen bonding, cation exchange and chelating effect. With its excellent adsorption capacity for cationic dyes, pH-independent adsorption capability for metal ions, easy separation ability, satisfactory stability and good reusability, FS@CS-PAA can become an ideal candidate for wastewater treatment.