Primary Amine Groups Research Articles

Enantioselective Synthesis of Azatricycles via Post-Ugi Cyclizations.

We report a new method to create enantioenriched azatricycles using chiral α-amino acids in a two-step process after an Ugi reaction. Amino acids are great building blocks for making pure chiral molecules. Using chiral natural molecules in multicomponent reactions (MCRs) helps increase their variety by adding new chiral centers. The Ugi reaction, discovered by Ivar Karl Ugi in 1959, is a versatile MCR that helps create complex molecular structures and natural products through additional transformations called post-Ugi modifications. Designing these modifications requires selecting the right amine, acid, aldehyde/ketone, and isocyanide. Amino acids, with their primary amine and carboxylic acid groups and a pre-existing chiral center, are ideal for making diverse and selective post-Ugi modifications. Our method uses ipso-cyclization and aza-Michael cyclization with hypervalent iodine to create various azaspirotricyclic structures with high stereocontrol. This approach works well with different substrates and shows promise for further development in drug discovery.

Preparation of styrene‐phenylamine monomer copolymer nanospheres and its performance for stabilizing CO2 foam

AbstractImproving the stability of CO2 foam is a core concern in CO2 foam flooding oil recovery technology. Using hydrophobic nano‐SiO2 to enhance the stability of CO2 foam is a common approach, but hydrophobic nano‐SiO2 faces challenges, such as easy aggregation, difficult dispersion, and performance needs to improve. In this article, a novel dispersion of styrene‐phenylamine monomer copolymer (PSSN) nanosphere with primary amine groups on the surface was synthesized. The synthesis conditions of PSSN were optimized, and its performance for stabilizing CO2 foam was evaluated. The experimental results demonstrated that PSSN had better performance for stabilizing CO2 foam than that of hydrophobic nano‐SiO2 when using cocamidopropyl betaine (CAB) as the foaming agent. With the CAB concentration of 4000 mg/L and PSSN concentration of 100 mg/L in the brine having salinity of 8460 mg/L, the half‐life of CO2 foam at 90°C was 131 min, which was 43 min longer than that stabilized by hydrophobic nano‐SiO2 under the same conditions. This is for the first time that polystyrene microspheres with amine groups on the surface was used to stabilize CO2 foam. The study provides a new nanoparticle option for stabilizing CO2 foam.

Europium-Infused Polystyrene Nanoparticles for Enhanced Bacterial Labeling in Microscopic Imaging

Luminescence microscopic imaging has become an indispensable tool in diagnostics and therapeutics. Lanthanide luminescent complexes (LLCs) have proven to be invaluable in this endeavor due to certain attractive characteristics such as long decay times, large Richardson shifts and narrow emission bands. However, the insolubility of these complexes and the negative effects of the aqueous environment on their photophysical properties still restrict their biological applications. By embedding luminescent Eu3+ complexes into polystyrene nanoparticles (NPs), these complexes can not only maintain their photophysical properties, but even enhance them. This leads to exceptionally high quantum yields (> 90 %) and decay times ( >800 μs). In addition, the surfaces of the NPs described here are covered with primary amine groups, which may be exploited for various interesting bioconjugation chemistries. In the present application, they were modified with N-hydroxysuccinimide (NHS) esters and then coupled either electrostatically or covalently to both, Gram-positive and Gram-negative bacteria, labeling them for luminescence microscopic imaging. This, to the best of our knowledge, is the first report of polymer NPs infused with LLCs for bacteria labeling.

Enhancing gene delivery efficiency with amphiphilic chitosan modified by myristic acid and tertiary amino groups

The aim of this study is to synthesize new amphiphilic chitosan containing myristic acid as the hydrophobic tail and tertiary amine groups as the hydrophilic head and to evaluate the gene delivery efficiency. In this context, the primary amine groups of chitosan were first modified with myristic acid (Chi-M), followed by the modification of the methylol groups with 3-dimethylamino-1-propyl chloride hydrochloride. The chemical characterization of this chitosan formulation (Chi-MA) was determined using nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FTIR) analysis and gel permeation chromatography-size exclusion chromatography. Chi-MA nanoparticles were prepared via ionic gelation, and particle size, polydispersity and zeta potential were determined. The nanoparticles were evaluated for their proton buffering capacity and gene complexing capacity. Additionally, the cytotoxicity of Chi-MA on HEK293T cells was determined via MTT assay, and the transfection efficiency of Chi-MA was analyzed by a flow cytometer. The results indicate a significant increase in gene complexing capacity (8-fold) and nanoparticle formation ability of Chi-MA compared to other chitosan formulations. Chi-MA nanoparticles showed no toxicity against HEK293T cells and exhibited the highest transfection efficiency with significantly lower nanoparticle: gene ratios compared to previous studies. These findings demonstrate the effective use of amphiphilic Chi-MA as a gene carrier.

Controlled Synthesis of Bioderived Poly(limonene carbonate)-Oligolysine Hybrid Macromolecules.

A straightforward and stepwise functionalization of poly(limonene carbonate) (PLC) was achieved through the use of thiol-ene click chemistry introducing primary amine groups. These amines are initiating points for N-carboxy anhydride (NCA) ring-opening polymerization (ROP) reactions, allowing us to modify the PLC backbone with oligolysine fragments, thereby creating a polymer brush type macromolecule. These newly prepared biohybrid structures show a clear hydrophilic behavior as evident from their physical behavior and contact angle measurements.

Co-delivery of antimicrobial peptide and Prussian blue nanoparticles by chitosan/polyvinyl alcohol hydrogels

Altered skin integrity increases the chance of infection, and bacterial infections often lead to a persistent inflammatory response that prolongs healing time. Functional artificial hydrogels are receiving increasing attention as suitable wound dressing barrier. However, the antimicrobial effect of the new dressing still needs to be explored in depth. In this work, the antimicrobial peptide MSI-1 was covalently attached to chitosan-modified poly (vinyl alcohol) hydrogels mixed with Prussian blue nanoparticles (PBNPs) via a primary amine group coupled to a carboxyl group. The synthesized hydrogel has a long-lasting antimicrobial surface and is able to maintain its bactericidal effect on Staphylococcus aureus and Escherichia coli for 24 h. Due to the presence of PBNPs, the hydrogel was able to rise to 48.3 °C within 10 min under near infrared (NIR) light irradiation at a wavelength of 808 nm and maintain this mild temperature to avoid bacterial biofilms. The hydrogel showed >90 % survival in co-culture with cells for 3 d and did not damage major organs in animal experiments. Thus, the photothermal dual-mode antimicrobial hydrogel synthesized in this study increases the selectivity as a safe and efficient wound dressing for the treatment of infected skin defects.

Evaluation of Adsorption Ability of Lewatit® VP OC 1065 and Diaion™ CR20 Ion Exchangers for Heavy Metals with Particular Consideration of Palladium(II) and Copper(II).

The adsorption capacities of ion exchangers with the primary amine (Lewatit® VP OC 1065) and polyamine (Diaion™ CR20) functional groups relative to Pd(II) and Cu(II) ions were tested in a batch system, taking into account the influence of the acid concentration (HCl: 0.1-6 mol/L; HCl-HNO3: 0.9-0.1 mol/L HCl-0.1-0.9 mol/L HNO3), phase contact time (1-240 min), initial concentration (10-1000 mg/L), agitation speed (120-180 rpm), bead size (0.385-1.2 mm), and temperature (293-333 K), as well as in a column system where the variable operating parameters were HCl and HNO3 concentrations. There were used the pseudo-first order, pseudo-second order, and intraparticle diffusion models to describe the kinetic studies and the Langmuir and Freundlich isotherm models to describe the equilibrium data to obtain better knowledge about the adsorption mechanism. The physicochemical properties of the ion exchangers were characterized by the nitrogen adsorption/desorption analyses, CHNS analysis, Fourier transform infrared spectroscopy, the sieve analysis, and points of zero charge measurements. As it was found, Lewatit® VP OC 1065 exhibited a better ability to remove Pd(II) than Diaion™ CR20, and the adsorption ability series for heavy metals was as follows: Pd(II) >> Zn(II) ≈ Ni(II) >> Cu(II). The optimal experimental conditions for Pd(II) sorption were 0.1 mol/L HCl, agitation speed 180 rpm, temperature 293 K, and bead size fraction 0.43 mm ≤ f3 < 0.6 mm for Diaion™ CR20 and 0.315-1.25 mm for Lewatit® VP OC 1065. The maximum adsorption capacities were 289.68 mg/g for Lewatit® VP OC 1065 and 208.20 mg/g for Diaion™ CR20. The greatest adsorption ability of Lewatit® VP OC 1065 for Pd(II) was also demonstrated in the column studies. The working ion exchange in the 0.1 mol/L HCl system was 0.1050 g/mL, much higher compared to Diaion™ CR20 (0.0545 g/mL). The best desorption yields of %D1 = 23.77% for Diaion™ CR20 and 33.57% for Lewatit® VP OC 1065 were obtained using the 2 mol/L NH3·H2O solution.

Preparation and application of multiple particle binding-liposomes for electrochemiluminescent signal amplification in bioassays.

In this study, multiple particle binding-liposomes (MPB-Lips), encapsulating the luminophore tris(2',2-bipyridyl)ruthenium (II) complex ([Ru(bpy)3]2+), were developed as an electrochemiluminescence (ECL) signal amplifier and were applied to detect the model analyte streptavidin (SA) using the indirect competitive ECL method. The MPB-Lips were prepared by mixing various ratios of two different liposomes-one containing a phospholipid with a primary amine group and a biotinyl group (BIO/NH2-Lip) and one containing a phospholipid with an N-hydroxysuccinimide group (NHS-Lip) to allow binding between particles via amide bonds. Quartz crystal microbalance analysis using SA-modified gold-coated quartz crystals showed that the frequency shift values of MPB-Lips gradually decreased in the order BIO/NH2-Lip:NHS-Lip = 1:0 < 1:1 < 1:3 < 1:5. This indicated that MPB-Lips were successfully formed. The indirect competitive ECL method using SA-modified gold electrodes showed that the 1:5-Lip system had greater sensitivity than the 1:0-Lip system-the limit of detection and quantification values for the systems were 1.84 and 6.30μgmL-1 for 1:0-Lip, and 1.20 and 1.74μgmL-1 for 1:5-Lip. Finally, the recovery of SA spiked in fetal bovine serum samples using the 1:5-Lip system showed good accuracy and precision with a recovery rate of 83-106% and relative standard deviation of 4-14%. Our study demonstrated that the MPB-Lips system was an effective and useful ECL amplifier and the ECL method using MPB-Lips could be applied to detect an analyte in a real sample.

Investigating the catalytic influence of MIL-101(Cr) and MIL-101(Cr)-NH2 on glucose dehydration into 5-hydroxymethylfurfural and modelled through response surface methodology

Dehydration of glucose into 5-hydroxymethylfurfural (5-HMF) is an effective approach for generating bio-based chemicals. Metal-organic frameworks (MOFs) are notable catalysts for this process due to their unsaturated metal centers. Functionalized MOFs further enhance these catalytic properties. This study investigates the catalytic abilities of MIL-101(Cr) and MIL-101(Cr)-NH2 for glucose dehydration into 5-HMF using an H2O + DMSO solvent system. Using Response Surface Methodology (RSM), the reaction parameters (temperature, time, and catalyst amount) were optimized to maximize 5-HMF yield. Results showed that at 180 °C, MIL-101(Cr) achieved a 5-HMF yield of 21 % with a selectivity of 22 %, while MIL-101(Cr)-NH2 achieved a 5-HMF yield of 55 % with a selectivity of 56 %. MIL-101(Cr) demonstrated a glucose conversion rate of 92 %, and MIL-101(Cr)-NH2 achieved a conversion rate of 99 % after 3 h at 180 °C. The optimized 5-HMF yield predicted by RSM for MIL-101(Cr) was 53.8 %, whereas the experimentally obtained value was 24.23 %. For MIL-101(Cr)-NH2, the predicted 5-HMF yield was 35.46 %, with an experimental value of 47.51 %. The Lewis acidic nature of MIL-101(Cr) arises from the Cr sites, while MIL-101(Cr)-NH2 exhibits both Lewis acidic characteristics from the Cr sites and Brønsted basic characteristics from the non-coordinated primary amine groups. The experimental results highlight the potential of MIL-101(Cr)-NH2, which produced a higher 5-HMF yield compared to MIL-101(Cr). The dual nature of MIL-101(Cr)-NH2 enhances glucose dehydration to 5-HMF, resulting in significantly higher yields. This study underscores the effectiveness of MIL-101(Cr)-NH2 in converting glucose to 5-HMF, advancing biomass utilization efficiency.

Conjugation of primary amine groups in targeted proteomics.

Primary amines, in the form of unmodified N-terminus of peptide/protein and unmodified lysine residue, are perhaps the most important functional groups that can serve as the starting points in proteomic analysis, especially via mass spectrometry-based approaches. A variety of multifunctional probes that conjugate primary amine groups through covalent bonds have been developed and employed to facilitate protein/protein complex characterization, including identification, quantification, structure and localization elucidation, protein-protein interaction investigation, and so forth. As an integral part of more accurate peptide quantification in targeted proteomics, isobaric stable isotope-coded primary amine labeling approaches eventually facilitated protein/peptide characterization at the single-cell level, paving the way for single-cell proteomics. The development and advances in the field can be reviewed in terms of key components of a multifunctional probe: functional groups and chemistry for primary amine conjugation; hetero-bifunctional moiety for separation/enrichment of conjugated protein/protein complex; and functionalized linker/spacer. Perspectives are primarily focused on optimizing primary amine conjugation under physiological conditions to improve characterization of native proteins, especially those associated with the surface of living cells/microorganisms.

Preparation of hydrogel from the hydroalcoholic root extract of Premna integrifolia L. and its mediated green synthesis of silver nanoparticles for wound healing efficacy

The current investigation concentrated on the fabrication of silver nanoparticles through the root of Premna integrifolia L. The antibacterial and wound healing effects of their silver nanoparticles-hydrogel and root extract-hydrogel were evaluated. The hydroalcoholic root extract of P. integrifolia was enriched with crocetin, ferulic acid, oleanolic acid, oleic acid, syringic acid, and vanillin. The silver nanoparticles were biosynthesized through secondary metabolite-enriched hydroalcoholic root extract (5 %) when mixed with 1 mM AgNO3 and kept under sunlight for 10 minutes. They showed an optimum surface plasmon resonance (SPR) at 447 nm. The aldehyde, phenol, and primary amine groups of the extract reduce silver cations into nanoparticles. The nanoparticles band gap of 2.06 eV showed their semi-conductance behavior. The nanoparticles were spherical, uniformly distributed, and stable. The nanoparticles had a good roughness profile and 57.55 % elemental silver. The silver nanoparticles-hydrogel (10 %) showed an efficient 11±0.11 nm zone of inhibition of S. aureus in comparison to the root extract-hydrogel (10 %), i.e., 9±0.15 nm. The nanoparticles-hydrogel and the root extract-hydrogel did not show noticeable symptoms of acute dermal toxicity. The nanoparticles-hydrogel (10 %) and the root extract-hydrogel (10 %) healed 99.9 % and 97.3 % of the S. aureus- infected wound, respectively. The nanoparticle-hydrogel efficiently induced re-epithelialization in the dermis of S. aureus-infected wound compared to the extract-hydrogel. The nanoparticle-hydrogel enhanced the rate of wound closure.

Iron-Catalyzed Primary Amination of C(sp3)-H Bonds.

Primary amines are privileged molecules in drug development. Yet, there is a noticeable scarcity of methods for directly introducing a primary amine group into the ubiquitous C(sp3)-H bonds within organic compounds. Here, we report an iron-based catalytic system that enables direct primary amination of C(sp3)-H bonds under aqueous conditions and air. Various types of C(sp3)-H bonds, including benzylic, allylic, and aliphatic ones, can be readily functionalized with high selectivity and efficiency. The broad utility of this method has been further verified by late-stage amination of 11 complex bioactive molecules. Mechanistic studies unveil a protonated iron-nitrene complex as the key intermediate for the C-H bond activation. This work extends the toolbox for direct C(sp3)-H functionalizations, opening up new opportunities for late-stage modifications of organic molecules.

Cyanobacterial Ampholyte Hydrogels Developed by the Cationization of Sulfated Polysaccharides and Their Cell-Compatibility.

Sacran is a cyanobacterial supergiant polysaccharide with carboxylate and sulfate groups that exhibits antiallergic and antiinflammatory properties. However, its high anionic functions restrict cell compatibility. Quaternary ammonium groups were substituted to form sacran ampholytes, and the cell compatibility of the cationized sacran hydrogels was evaluated. The cationization process involved the reaction of N-(3-chloro-2-hydroxypropyl)trimethylammonium chloride with the primary amine or hydroxyl groups of sacran. The degree of cationization ranged from 32 to 87% for sugar residues. Hydrogels of sacran ampholytes were prepared by annealing their dried sheets by thermal cross-linking; these hydrogels exhibited anisotropic expansion properties. The water contact angle on the hydrogels decreased from 26.5 to 15.3° with an increase in the degree of cationization, thereby enhancing hydrophilicity. The IC50 values of sacran ampholytes decreased with an increased degree of cationization, resulting in a reduction in cytotoxicity toward the L-929 mouse fibroblast cell line. This reduction was associated with an increase in the cell proliferation density after 3 days of incubation. Scanning electron microscopy images showed fibroblast intercellular connections. Therefore, the sacran ampholyte hydrogel exhibited increased hydrophilicity and cell compatibility, which is beneficial for various biomedical applications.

Iron-catalyzed non-directed arene C-H difluoromethylation

Practical, undirected and selective catalytic functionalization of unactivated arenes remains a challenging problem in organic synthesis. We herein report a bioinspired L-cystine-derived ligand BCPOM/Fe-enabled innate C-H difluoromethylation of unactivated arenes as limiting reagents with stable and inexpensive BrCF2CO2Et as the difluoromethylation source in high efficiency. Notably, this method uses environmentally benign H2O2 as the sole oxidant, and enables late-stage functionalization and exceptionally functional-group tolerance, even including oxidation-labile aldehyde, phenolic hydroxy, primary amine, and boronic acid groups, which is difficult to access by current means.

Preparation and Mechanism of Shale Inhibitor TIL-NH2 for Shale Gas Horizontal Wells.

In this study, a new polyionic polymer inhibitor, TIL-NH2, was developed to address the instability of shale gas horizontal wells caused by water-based drilling fluids. The structural characteristics and inhibition effects of TIL-NH2 on mud shale were comprehensively analyzed using infrared spectroscopy, NMR spectroscopy, contact angle measurements, particle size distribution, zeta potential, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. The results demonstrated that TIL-NH2 significantly enhances the thermal stability of shale, with a decomposition temperature exceeding 300 °C, indicating excellent high-temperature resistance. At a concentration of 0.9%, TIL-NH2 increased the median particle size of shale powder from 5.2871 μm to over 320 μm, effectively inhibiting hydration expansion and dispersion. The zeta potential measurements showed a reduction in the absolute value of illite's zeta potential from -38.2 mV to 22.1 mV at 0.6% concentration, highlighting a significant decrease in surface charge density. Infrared spectroscopy and X-ray diffraction confirmed the formation of a close adsorption layer between TIL-NH2 and the illite surface through electrostatic and hydrogen bonding, which reduced the weakly bound water content to 0.0951% and maintained layer spacing of 1.032 nm and 1.354 nm in dry and wet states, respectively. Thermogravimetric analysis indicated a marked reduction in heat loss, particularly in the strongly bound water content. Scanning electron microscopy revealed that shale powder treated with TIL-NH2 exhibited an irregular bulk shape with strong inter-particle bonding and low hydration degree. These findings suggest that TIL-NH2 effectively inhibits hydration swelling and dispersion of shale through the synergistic effects of cationic imidazole rings and primary amine groups, offering excellent temperature and salt resistance. This provides a technical foundation for the low-cost and efficient extraction of shale gas in horizontal wells.

Cross-linking of mesoporous bioactive glass nanoparticle incorporated gelatin hydrogels by tannic acid with enhanced mechanical performance and stability

Gelatin-based hydrogels are used in diverse biomedical applications, such as wound dressings, tissue regeneration, and cell culture models. However, gelatin requires additional cross-linking to form a stable hydrogel. Tannic acid (TA), a polyphenolic compound, can undergo the Michael addition reaction and Schiff's base reaction with primary amine groups in neutral aqueous solutions. In this work, TA was selected as a cross-linker of gelatin to fabricate hydrogels reacting with primary amine groups in the gelatin molecular chain. Primary amine-modified mesoporous bioactive glass nanoparticles (AMBGNs) were added to further enhance the cross-linking of the system. The swelling ratios and weight losses showed that the most stable hydrogels retain approximately 53 % of their mass after 28 days of immersion in PBS solution. Young's modulus increased significantly with the increase in the content of TA and AMBGNs. The addition of TA and AMBGNs also resulted in a substantial reduction of gelation time. The prepared hydrogels possessed adequate stability and mechanical properties and showed potential for customized application in a variety of clinical service settings, such as wound healing, bone regeneration, and soft tissue regeneration.

Chitosan Properties: A Preliminary Review

The content of amino groups in chitosan becomes the main cause of its differences from chitin in the context of structures and properties such as their chelation, flocculation, and biological functions. Furthermore, the random distribution of chitosan makes it easier to generate intra-and inter-molecular hydrogen bonds. Also, the existence of two hydroxyl groups and one primary amine group in chitosan, which can donate a free pair of electrons, make it soluble in diluted aqueous acetic solvents, and allow the formation of the coordination bonds that increase the possibilities for chemical modification. Its modification includes the incorporation of hydrophobic groups. Therefore, this paper reviews the properties of chitosan.

Crystal structures of the isomeric dipeptides l-glycyl-l-me-thio-nine and l-me-thionyl-l-glycine.

The oxidation of me-thionyl peptides can contribute to increased biological (oxidative) stress and development of various inflammatory diseases. The conformation of peptides has an important role in the mechanism of oxidation and the inter-mediates formed in the reaction. Herein, the crystal structures of the isomeric dipeptides Gly-Met (Gly = glycine and Met = me-thio-nine) and Met-Gly, both C7H14N2O3S, are reported. Both mol-ecules exist in the solid state as zwitterions with nominal proton transfer from the carb-oxy-lic acid to the primary amine group. The Gly-Met mol-ecule has an extended backbone structure, while Met-Gly has two nearly planar regions kinked at the C atom bearing the NH3 group. In the crystals, both structures form extensive three-dimensional hydrogen-bonding networks via N-H⋯O and bifurcated N-H⋯(O,O) hydrogen bonds having N⋯O distances in the range 2.6619 (13)-2.8513 (13) Å for Gly-Met and 2.6273 (8)-3.1465 (8) Å for Met-Gly.

Assessing the Acidic and Alkaline Recalcitrance of Covalently Modified Surface Amines on Ordered Mesoporous Carbon.

Ordered mesoporous carbon (OMC) scaffolds were covalently modified with primary amine groups by means of oxidation-coupling, yielding C-O-C bonds, or organometallic activation-coupling, yielding C-C bonds. The aminated OMCs were stressed by immersion in either 1 M hydrochloric acid or 1 M sodium hydroxide solutions at room temperature for 6 h and characterized by nitrogen sorption, electron microscopy, low-angle X-ray diffraction, thermogravimetric analysis, and the 4-nitrobenzaldehyde assay. Results demonstrate that aminated surfaces of OMC by butyllithium grafting are stable toward both 1 M HCl and 1 M NaOH, whereas the oxidation-aminated OMC surfaces can withstand 1 M NaOH only. This study illustrates the importance of chemical testing to supplant chemical intuition when tailoring carbon surfaces for applications where strong acids or bases are employed. This is especially emphasized for carbonaceous materials because of the surface heterogeneity among different carbon allotropes.

Graphene Oxide/Polyamidoamine G4 as a High Efficient and Eco-Friendly Adsorbent for Dichromate Ions.

In this study, GO/PAMAM4 was used as a biocompatible nanocomposite adsorbent to adsorb dichromate (DC) ions. In alkaline solutions, DC ions changed to chromate ions which were not adsorbed on the surface of adsorbent. Thus, experiments were carried out in acidic and neutral water solution. Under these conditions, adsorption sites of adsorbent were protonated primary and ternary amine groups of adsorbent shown as -NH3+ and -NHR2+, respectively, that adsorbed DC ions through electrostatic interaction. Adsorption isotherms of DC on GO/PAMAM4 were obtained under various ionic strengths, pHs and temperatures. Isotherms were analyzed by the ARIAN model. The highest observed adsorption capacity of this process was 246.7 mg g-1 at pH=0 and 318 K. Tests at pH=2 showed that this process was endothermic. Adsorption kinetic experiments were carried out under various initial DC concentrations, pHs, temperatures, shaking rates and ionic strengths and were analyzed by the KASRA model and intraparticle diffusion, ISO and NIPPON equations. Pb2+, Cd2+, Cr3+ and tannic acid (TA) were separated by GO/PAMAM4 from DC ions and the GO/PAMAM4 was recycled by using an alkaline solution.