Methionine-mediated synthesis of magnetic nanoparticles and functionalization with gold quantum dots for theranostic applications

• Arūnas Jagminas,
• Agnė Mikalauskaitė,
• Vitalijus Karabanovas and
• Jūrate Vaičiūnienė

Beilstein J. Nanotechnol. 2017, 8, 1734–1741, doi:10.3762/bjnano.8.174

• , peaked near 1515 cm−1, belongs to δs(NH3) mode and is indicative of the presence of charged amino groups [35][37]. The symmetric C–H deformation mode is also observed at 1341 cm−1 in the FTIR spectra of both pure methionine and CoFe2O4@Met. The attachment of methionine molecules during the synthesis of

Two-dimensional carbon-based nanocomposites for photocatalytic energy generation and environmental remediation applications

• Suneel Kumar,
• Ashish Kumar,
• Ashish Bahuguna,
• Vipul Sharma and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2017, 8, 1571–1600, doi:10.3762/bjnano.8.159

• structure, while other five phases have indirect band gaps in their bulk structures [62]. It is noteworthy to mention here that the polymeric graphitic carbon nitride (g-C3N4) has been reported as the most stable, highly ordered polymeric structure with pendant amino groups and tri-s-triazine (C6N7) as the

Development of polycationic amphiphilic cyclodextrin nanoparticles for anticancer drug delivery

• Gamze Varan,
• Juan M. Benito,
• Carmen Ortiz Mellet and
• Erem Bilensoy

Beilstein J. Nanotechnol. 2017, 8, 1457–1468, doi:10.3762/bjnano.8.145

• therapy can be provided with lower drug dose. Zeta potential measurements indicate that 6OCaproβCD has a negative surface charge unlike the other formulations. In this study, PC βCDC6 has a strong positive surface charge owing to polycationic amino groups. This amphiphilic CD derivative was previously

Micro- and nano-surface structures based on vapor-deposited polymers

• Hsien-Yeh Chen

Beilstein J. Nanotechnol. 2017, 8, 1366–1374, doi:10.3762/bjnano.8.138

• polymerization chamber to form a multi-phasic reactive species (monomer vapors). The copolymerization processes spontaneously occur when the multicomponent copolymer coatings form on substrates [41][46][47]. A wide range of functionalities was demonstrated: combinations of active esters, carbonyls, amino groups

Recombinant DNA technology and click chemistry: a powerful combination for generating a hybrid elastin-like-statherin hydrogel to control calcium phosphate mineralization

• Mohamed Hamed Misbah,
• Mercedes Santos,
• Luis Quintanilla,
• Christina Günter,
• Matilde Alonso,
• Andreas Taubert and
• José Carlos Rodríguez-Cabello

Beilstein J. Nanotechnol. 2017, 8, 772–783, doi:10.3762/bjnano.8.80

• modify 60% of the amino groups distributed along the recombinamer chain was dissolved in 1 mL of dimethylformamide (DMF). This solution was then added to a solution of the ELR at 25 mg/mL in DMF. The reaction was performed under an inert atmosphere and with continuous stirring at room temperature for 48

• by adding cyclooctyne groups by amidation, with the ε-amino groups of the lysine residues being converted into cyclooctyne bearing an activated carboxyl group (N-succinimidyl ester), as described elsewhere [25], to form component 2 (Figure 1B). Azide derivatization of ELRs is indicated by an increase

First examples of organosilica-based ionogels: synthesis and electrochemical behavior

• Andreas Taubert,
• Ruben Löbbicke,
• Barbara Kirchner and
• Fabrice Leroux

Beilstein J. Nanotechnol. 2017, 8, 736–751, doi:10.3762/bjnano.8.77

• sulfonate groups, but also to amino groups of the linker and on to other sulfonates from there. This effect may contribute to the rather efficient conduction but the details are currently under investigation using solid-state NMR spectroscopy. The hypothesis of very mobile protons is however qualitatively

Dispersion of single-wall carbon nanotubes with supramolecular Congo red – properties of the complexes and mechanism of the interaction

• Anna Jagusiak,
• Barbara Piekarska,
• Tomasz Pańczyk,
• Małgorzata Jemioła-Rzemińska,
• Elżbieta Bielańska,
• Barbara Stopa,
• Grzegorz Zemanek,
• Janina Rybarska,
• Irena Roterman and
• Leszek Konieczny

Beilstein J. Nanotechnol. 2017, 8, 636–648, doi:10.3762/bjnano.8.68

• red spectrum after acidification to pH 4.3 (B); free SWNT suspension spectrum (C). Congo red structure: (A) at physiological pH; (B) ionization of the amino groups at acidic pH and conversion to the quinoid form leading to the change of colour. Binding of CR to SWNTs in solutions of different ionic

Comparison of four methods for the biofunctionalization of gold nanorods by the introduction of sulfhydryl groups to antibodies

• Xuefeng Wang,
• Zhong Mei,
• Yanyan Wang and
• Liang Tang

Beilstein J. Nanotechnol. 2017, 8, 372–380, doi:10.3762/bjnano.8.39

• solution and the CTAB bilayer density [15]. The common ligand exchange is the replacement of the CTAB of GNR with thiol-terminated ligands, such as thiolated poly(ethylene glycol) and mercaptoundecanoic acid [10][11]. These agents can link the amino groups of biomolecules with the carboxylic group from

• -thiolated antibodies has also been developed [18]. However, the reaction between bi-functional linkers of Traut’s reagent and the primary amino groups on the antibody occurs randomly. Thus, the antibody activity would be lost when the amino groups were excessively thiolated in antigen-binding regions [19

• functionalization strategy is through the reaction of amino groups of thiol-poly(ethylene glycol)amine (SH-PEG-NH2) with carboxyl groups in the anti-IgG by using EDC. The thiol moiety of SH-PEG-NH2 can be directly conjugated to GNRs through the Au–S bond. In the current work, we compared the four abovementioned

Tailoring bifunctional hybrid organic–inorganic nanoadsorbents by the choice of functional layer composition probed by adsorption of Cu²⁺ ions

• Veronika V. Tomina,
• Inna V. Melnyk,
• Yuriy L. Zub,
• Aivaras Kareiva,
• Miroslava Vaclavikova,
• Gulaim A. Seisenbaeva and
• Vadim G. Kessler

Beilstein J. Nanotechnol. 2017, 8, 334–347, doi:10.3762/bjnano.8.36

• useful in further grafting of new functions via organic condensation reactions [30]. In the studies examining one-step preparations of nanoparticles bearing 3-aminopropyl groups it was shown that heating a suspension in DMF at 100 °C for 24 h did not increase the content of surface amino groups, but

• improved the stability of the surface layer [28]. It was shown [27] that the introduction of 3-aminopropyltriethoxysilane (APTES) to TEOS sol in ethanol in a molar ratio of 1:1 yielded nanoparticles with an average diameter around 66 nm, but their surface layer contained almost no amino groups. At a TEOS

• /APTES molar ratio of 3:1, the surface layer did contain amino groups (1.56 mmol/g), but the particle size decreases to about 9 nm. When the order of components introduction was changed, the content of functional groups increased to 3.2 mmol/g. However, according to 29Si NMR spectroscopy, the content of

Comparison of four functionalization methods of gold nanoparticles for enhancing the enzyme-linked immunosorbent assay (ELISA)

• Paula Ciaurriz,
• Fátima Fernández,
• Edurne Tellechea,
• Jose F. Moran and
• Aaron C. Asensio

Beilstein J. Nanotechnol. 2017, 8, 244–253, doi:10.3762/bjnano.8.27

• of free amine groups (few lysine amino acid residues) compared to the antibody molecule. The lower availability of free amino groups could hamper the attachment of peroxidase in the covalent strategy (Figure 1c), although more experiments should be performed to confirm this. Consequently, this would

Streptavidin-coated gold nanoparticles: critical role of oligonucleotides on stability and fractal aggregation

• Roberta D'Agata,
• Pasquale Palladino and
• Giuseppe Spoto

Beilstein J. Nanotechnol. 2017, 8, 1–11, doi:10.3762/bjnano.8.1

• has been demonstrated that the interaction between proteins and citrate-stabilized AuNPs occurs through a mechanism involving carboxylate–ammonium interactions established between citrate and lysine or histidine amino groups on the protein surface. The mechanism also includes contributions from steric

Chitosan-based nanoparticles for improved anticancer efficacy and bioavailability of mifepristone

• Huijuan Zhang,
• Fuqiang Wu,
• Yazhen Li,
• Xiping Yang,
• Jiamei Huang,
• Tingting Lv,
• Yingying Zhang,
• Jianzhong Chen,
• Haijun Chen,
• Yu Gao,
• Guannan Liu and
• Lee Jia

Beilstein J. Nanotechnol. 2016, 7, 1861–1870, doi:10.3762/bjnano.7.178

• reactive amino side groups, chitosan could be made available via chemical modifications or ionic interactions [14]. Chitosan-bearing protonated amino groups could interact with a wide variety of natural or synthetic anionic species, such as negatively charged proteins, DNA [15][16][17][18][19], and some

Effective intercalation of zein into Na-montmorillonite: role of the protein components and use of the developed biointerfaces

• Ana C. S. Alcântara,
• Margarita Darder,
• Pilar Aranda and
• Eduardo Ruiz-Hitzky

Beilstein J. Nanotechnol. 2016, 7, 1772–1782, doi:10.3762/bjnano.7.170

• ninhydrin spray solution as revealing agent confirmed the presence of protein in the extracted liquid phase, showing a purplish color resulting from reaction between ninhydrin and free amino groups from amino acids of solubilized zein (Supporting Information File 1, Figure S2). The molecular weight of the

• signals between 173–175 ppm due to carbonyls present in the peptide groups in both the main chain and the protein side chains. The signals at 128 ppm, those from 45 to 70 and those from 15 to 45 ppm are assigned to amino acid aromatic side chains, α-carbons linked to amino groups, and carbons from the

• values, reaching wavenumber values of 1664 cm−1 in the biohybrids (Figure 3b–d). This shift may be a consequence of the perturbation introduced in the amide group by interactions between the involved protonated amino groups and the negatively charged sites in the clay structure. Similar results involving

An efficient recyclable magnetic material for the selective removal of organic pollutants

• Clément Monteil,
• Nathalie Bar,
• Agnès Bee and
• Didier Villemin

Beilstein J. Nanotechnol. 2016, 7, 1447–1453, doi:10.3762/bjnano.7.136

• , respectively. Referring back to Figure 3, the repulsion between negative charges increases with the number of introduced phosphonate groups. At pH 14, we observe a similar evolution, but all values of qmax are much lower because of the absence of electrostatic attraction, whereas all the amino groups are

High antiviral effect of TiO₂·PL–DNA nanocomposites targeted to conservative regions of (−)RNA and (+)RNA of influenza A virus in cell culture

• Asya S. Levina,
• Marina N. Repkova,
• Elena V. Bessudnova,
• Ekaterina I. Filippova,
• Natalia A. Mazurkova and
• Valentina F. Zarytova

Beilstein J. Nanotechnol. 2016, 7, 1166–1173, doi:10.3762/bjnano.7.108

• noncovalently immobilized on TiO2 nanoparticles (≈5 nm in diameter) in the anatase form [17] due to the affinity of polylysine to the TiO2 surface. This affinity can be explained in all likelihood by the electrostatic interaction between the positively charged amino groups of PL and the negatively charged TiO2

• surface at neutral pH [22]. Since the PL–DNA conjugate contains a 100-fold excess of the amino groups over an oligonucleotide [17], the majority of the amino groups are free to interact with the negatively charged surface of the TiO2 nanoparticles. The resultant TiO2·PL–DNA nanocomposite was used to

Multiwalled carbon nanotube hybrids as MRI contrast agents

• Nikodem Kuźnik and
• Mateusz M. Tomczyk

Beilstein J. Nanotechnol. 2016, 7, 1086–1103, doi:10.3762/bjnano.7.102

• covalent transformations, e.g., the data were shown to couple oxidized SWCNT with hyaluronic acid containing amino groups [44]. Liu described interesting mass growth during the heating of SPIO–MWCNT hybrids above 400 °C in TGA, which was explained as oxidation of iron(II) in Fe3O4 to iron(III) in Fe2O3

Facile synthesis of water-soluble carbon nano-onions under alkaline conditions

• Gaber Hashem Gaber Ahmed,
• Rosana Badía Laíño,
• Josefa Angela García Calzón and
• Marta Elena Díaz García

Beilstein J. Nanotechnol. 2016, 7, 758–766, doi:10.3762/bjnano.7.67

• , using the bottom-up approach, we prepared C-dots based on the thermal carbonization of a mixture of nitrogen-containing organic compounds, ethyleneglycol bis(2-aminoethyl ether)-N,N,N′,N′-tetraacetic acid (EGTA) and Tris, thus providing them not only with surface hydroxy but also with amino groups

Chemiresistive/SERS dual sensor based on densely packed gold nanoparticles

• Sanda Boca,
• Cosmin Leordean,
• Simion Astilean and
• Cosmin Farcau

Beilstein J. Nanotechnol. 2015, 6, 2498–2503, doi:10.3762/bjnano.6.259

• , this stability decreases proportionally. Hence, to increase the stability of the concentrated collidal solution, the originally citrate-capped AuNPs were functionalized with folic acid molecules by electrostatic interaction between the negative surface of the particles and the positive amino groups of

Green and energy-efficient methods for the production of metallic nanoparticles

• Mitra Naghdi,
• Mehrdad Taheran,
• Satinder K. Brar,
• M. Verma,
• R. Y. Surampalli and
• J. R. Valero

Beilstein J. Nanotechnol. 2015, 6, 2354–2376, doi:10.3762/bjnano.6.243

• amino groups in chitosan and sulfonic groups in heparin can provide enough electrostatic attractive force for the formation and stabilization of the Au and Ag NPs. They observed an increasing trend in the size of the Ag NPs while increasing the concentration of Ag+ or heparin. The particle sizes of CTS

Self-organization of gold nanoparticles on silanated surfaces

• Htet H. Kyaw,
• Salim H. Al-Harthi,
• Azzouz Sellai and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2015, 6, 2345–2353, doi:10.3762/bjnano.6.242

• be covalently bonded to the oxygen from the SiO2 surface as a tripod structure (shown as type IV) with higher available amino groups oriented away from the substrate thus being available for binding gold nanoparticles [24]. These different types of orientation of APTES molecules could play an

Template-controlled mineralization: Determining film granularity and structure by surface functionality patterns

• Nina J. Blumenstein,
• Jonathan Berson,
• Stefan Walheim,
• Petia Atanasova,
• Johannes Baier,
• Joachim Bill and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2015, 6, 1763–1768, doi:10.3762/bjnano.6.180

• potential of the amino-functionalized SAM is charged slightly positive during the reaction [28][29] due to protonation of the amino groups (–NH3+) at this pH. Additionally, a Stern layer is present, which is formed by negatively charged counterions [29][30]. The particles in solution can interact with these

• agglomerates grow together (j–n) resulting in a rough surface for the final morphology. Deposition mechanism of mineralized ZnO nanoparticles on amino SAMs. The negative charges represent counterions attached to the positive surface charge (Stern layer) provided by protonated amino groups (–NH3

Peptide-equipped tobacco mosaic virus templates for selective and controllable biomineral deposition

• Klara Altintoprak,
• Axel Seidenstücker,
• Alexander Welle,
• Sabine Eiben,
• Petia Atanasova,
• Nina Stitz,
• Alfred Plettl,
• Joachim Bill,
• Hartmut Gliemann,
• Holger Jeske,
• Dirk Rothenstein,
• Fania Geiger and
• Christina Wege

Beilstein J. Nanotechnol. 2015, 6, 1399–1412, doi:10.3762/bjnano.6.145

• Wild type TMVwt and genetically modified TMVLys [76] (also named TMV–Lys here to underscore the functional amino groups exposed by its lysine side chains) were purified according to Gooding and Hebert [91]. Peptide conjugation onto the virus surface followed a protocol established on the basis of

• virus particles with thousands of surface-exposed amino groups of lysine residues (TMVLys) served as biotemplates for chemical conjugation reactions. (b) Hetero-bifunctional linker molecules (succinimidyl-(N-maleimidopropionamido) ester, SM(PEG)4) were coupled to TMVLys via N-hydroxysuccinimide (NHS

Natural and artificial binders of polyriboadenylic acid and their effect on RNA structure

• Giovanni N. Roviello,
• Domenica Musumeci,
• Valentina Roviello,
• Marina Pirtskhalava,
• Alexander Egoyan and
• Merab Mirtskhulava

Beilstein J. Nanotechnol. 2015, 6, 1338–1347, doi:10.3762/bjnano.6.138

• about 106 M−1. The binding activity of neomycin towards nucleic acids is attributed to its cationic nature due to the amino groups protonation at pH less than 7. Purine derivatives In the work of Davies [17] the poly(rA) recognition by different heteroaromatic compounds (Figure 6) was studied by means

Protein corona – from molecular adsorption to physiological complexity

• Lennart Treuel,
• Dominic Docter,
• Michael Maskos and
• Roland H. Stauber

Beilstein J. Nanotechnol. 2015, 6, 857–873, doi:10.3762/bjnano.6.88

• the HSA molecule from (−10.5 ± 1.3) mV for native HSA to (−19 ± 4) mV for HSAsuc (both in PBS at pH 7.4). For comparison, they also altered the carboxyl groups of the native HSA molecule by reacting them with ethylenediamine, thus, converting them into positively charged amino groups, creating an

Self-assembled anchor layers/polysaccharide coatings on titanium surfaces: a study of functionalization and stability

• Ognen Pop-Georgievski,
• Dana Kubies,
• Josef Zemek,
• Neda Neykova,
• Roman Demianchuk,
• Eliška Mázl Chánová,
• Miroslav Šlouf,
• Milan Houska and
• František Rypáček

Beilstein J. Nanotechnol. 2015, 6, 617–631, doi:10.3762/bjnano.6.63

• organic moieties and their covalent structure was further verified by independent IRRAS and XPS measurements. The IR spectra of the resulting anchor layers showed the characteristic in-plane bending modes, δin-plane(NH), of free and H-bonded amino groups in the region 1600–1650 cm−1. The covalent

• free hydroxy groups. (B) Immobilization of neridronate, APTES siloxane and poly(dopamine) anchor layers through surface specific reactions between the phosphonate, silane and catechol groups of corresponding compounds and hydroxy groups on the surface. (C) Covalent binding of ALG chains to amino groups