Key for crossing the BBB with nanoparticles: the rational design

• Sonia M. Lombardo,
• Marc Schneider,
• Akif E. Türeli and
• Nazende Günday Türeli

Beilstein J. Nanotechnol. 2020, 11, 866–883, doi:10.3762/bjnano.11.72

• ) are based on magnetite (Fe3O4) or maghemite (γ-Fe2O3) molecules encapsulated in polysaccharides, synthetic polymers or monomer coatings and have a size range from 1 to 100 nm [21][182]. SPIONs possess interesting magnetic properties and some formulations have already been approved as MRI contrast

Multilayer capsules made of weak polyelectrolytes: a review on the preparation, functionalization and applications in drug delivery

• Varsha Sharma and
• Anandhakumar Sundaramurthy

Beilstein J. Nanotechnol. 2020, 11, 508–532, doi:10.3762/bjnano.11.41

• changing the integrity or permeability. Magnetic NPs have shown greater cytotoxicity in comparison with microcapsules containing an equivalent amount of magnetite [79]. The first and foremost way of incorporating NPs into the shell is either by the adsorption of NPs over the sacrificial template or using

Use of data processing for rapid detection of the prostate-specific antigen biomarker using immunomagnetic sandwich-type sensors

• Camila A. Proença,
• Tayane A. Freitas,
• Thaísa A. Baldo,
• Elsa M. Materón,
• Flávio M. Shimizu,
• Gabriella R. Ferreira,
• Frederico L. F. Soares,
• Ronaldo C. Faria and
• Osvaldo N. Oliveira Jr.

Beilstein J. Nanotechnol. 2019, 10, 2171–2181, doi:10.3762/bjnano.10.210

• -linked immunosorbent assay. The approaches for immunoassays and data processing are generic, and therefore the strategies described here may provide a simple platform for clinical diagnosis of cancers and other types of diseases. Keywords: cancer biomarkers; magnetite nanoparticles; microfluidic devices

• ], including magnetic nanoparticles (MNPs) that can be exploited for their catalytic properties [10] and magnetic separation in pre-concentrating the analyte [11][12][13][14][15][16]. The most common magnetic nanoparticles used for this purpose are magnetite (Fe3O4) nanoparticles, which have a stronger

Magnetic properties of biofunctionalized iron oxide nanoparticles as magnetic resonance imaging contrast agents

• Natalia E. Gervits,
• Andrey A. Gippius,
• Alexey V. Tkachev,
• Evgeniy I. Demikhov,
• Sergey S. Starchikov,
• Igor S. Lyubutin,
• Alexander L. Vasiliev,
• Vladimir P. Chekhonin,
• Maxim A. Abakumov,
• Alevtina S. Semkina and
• Alexander G. Mazhuga

Beilstein J. Nanotechnol. 2019, 10, 1964–1972, doi:10.3762/bjnano.10.193

• nanoparticles located inside and outside of each capsule [11] and integration of the nanoparticles in the matrix of HSA threads, as will be discussed in this paper. The problem of distinguishing between magnetite Fe3O4 and maghemite γ-Fe2O3, both of which usually appear as synthesis products of iron oxide

• of the structure due to the presence of both magnetite Fe3O4 and maghemite γ-Fe2O3. Another method to distinguish between Fe2+ and Fe3+ and their positions in the crystal structure is Mössbauer spectroscopy. However, the use of ionizing radiation and radioactive sources in this method limits the

• possibility of its transfer to production. Raman spectroscopy can also be used to discriminate nanoscale magnetite and maghemite. However, this method gives only qualitative information about the iron oxide structure and does not allow the number of Fe2+ and Fe3+ atoms or their positions to be determined

The effect of magneto-crystalline anisotropy on the properties of hard and soft magnetic ferrite nanoparticles

• Hajar Jalili,
• Bagher Aslibeiki,
• Ali Ghotbi Varzaneh and
• Volodymyr A. Chernenko

Beilstein J. Nanotechnol. 2019, 10, 1348–1359, doi:10.3762/bjnano.10.133

• substituting iron ions in the magnetite structure. This indicates an increase of the interplane distances (d) in the spinel structure. Similar results have been reported for NixCo1−xFe2O4 NPs by Caetano and co-workers [15]. According to Bragg’s law, λ = 2d·sin θ, (λ is the wavelength of X-ray wavelength, here

• , tend to occupy both the B-sites and the smaller A-sites (see Figure 6). This mixed occupancy in cobalt-substituted magnetite nanoparticles has been confirmed by Mössbauer spectroscopy [30]. Therefore, it is expected that when cobalt ions substitute iron ions at the A-sites, an increasing Me–O bond

On the relaxation time of interacting superparamagnetic nanoparticles and implications for magnetic fluid hyperthermia

• Andrei Kuncser,
• Nicusor Iacob and
• Victor E. Kuncser

Beilstein J. Nanotechnol. 2019, 10, 1280–1289, doi:10.3762/bjnano.10.127

• -free nanoparticles, the Brownian relaxation mechanism becomes dominant over the Néel mechanism only for nanoparticles larger than a critical radius (e.g., 8 nm in the case of magnetite nanoparticles) [21]. In such conditions, the heat transfer mechanism might also be completed by a hysteretic loss (the

• magnetite nanoparticle based ferrofluids of different volume fractions were independently derived by alternative techniques [26][33]. Detailed experimental and methodological aspects involving a very diluted ferrofluid as reference are described in [26]. The adiabatic-like curve obtained in the case of a

• concentrated ferrofluid (φ = 0.094) consisting of quasi-ellipsoidal magnetite nanoparticles of average magnetic volume of 4.3 × 10−25 m3 dispersed in transformer oil, with a spontaneous magnetization Ms = 4.5 × 105 A m−2, as determined by DC low temperature magnetometry and an effective anisotropy energy

Photoactive nanoarchitectures based on clays incorporating TiO₂ and ZnO nanoparticles

• Eduardo Ruiz-Hitzky,
• Pilar Aranda,
• Marwa Akkari,
• Nithima Khaorapapong and
• Makoto Ogawa

Beilstein J. Nanotechnol. 2019, 10, 1140–1156, doi:10.3762/bjnano.10.114

• nanoparticles on the external surface of sepiolite fibres. The resulting ZnO–Fe3O4@sepiolite nanoarchitecture exhibits photoactivity due to the ZnO NPs, and the presence of magnetite NPs facilitates the recovery by the use of a magnet (Figure 4) [133]. Moreover, the presence of iron oxide could be useful also

• isopropoxide; reprinted with permission from [109], copyright 2008 American Chemical Society. ZnO-Fe3O4@sepiolite nanoarchitecture prepared in two steps: First, the fiber clay is modified by assembly of magnetite NPs. After that, the ZnO NPs are added yielding a magnetic photocatalyst. The STEM images on the

• right shows the silicate component (red), the magnetite NPs (green) and the ZnO NPs (blue) analyzed with an EDAX detector and a Gatan Tridiem energy filter; reprinted with permission from [133], copyright 2017 Elsevier. (A) TEM image of the Pt–TiO2@sepiolite clay nanoarchitectures prepared by a

Scavenging of reactive oxygen species by phenolic compound-modified maghemite nanoparticles

• Małgorzata Świętek,
• Yi-Chin Lu,
• Rafał Konefał,
• Liliana P. Ferreira,
• M. Margarida Cruz,
• Yunn-Hwa Ma and
• Daniel Horák

Beilstein J. Nanotechnol. 2019, 10, 1073–1088, doi:10.3762/bjnano.10.108

• , phenolic compounds with a higher number of hydroxy groups have enhanced ROS scavenging capability. In addition to low-molecular-weight phenolic compounds of natural origin, some inorganic nanoparticles also have antioxidant properties, e.g., zinc, cerium, magnesium oxide, magnetite, and silver [6][7][8][9

• functional groups. In this study, magnetite (Fe3O4) nanoparticles were synthetized by coprecipitation of iron(II) chloride and iron(III) chloride with ammonia and subsequently oxidized with hydrogen peroxide under mild acidic conditions. The resulting maghemite (γ-Fe2O3) has the benefit of higher chemical

• heated to 70 °C for 10 min, and 25% NH4OH (10 mL) in water (25 mL) was added dropwise. The mixture was heated at 90 °C for 1 h, and the particles were washed with water four times (50 mL for each wash) and dispersed in water (200 mL). To oxidize magnetite, 37% hydrochloric acid (150 µL) in water (5 mL

Fe₃O₄ nanoparticles as a saturable absorber for giant chirped pulse generation

• Ji-Shu Liu,
• Xiao-Hui Li,
• Abdul Qyyum,
• Yi-Xuan Guo,
• Tong Chai,
• Hua Xu and
• Jie Jiang

Beilstein J. Nanotechnol. 2019, 10, 1065–1072, doi:10.3762/bjnano.10.107

• ultrafast recovery time of 18–30 ps [3]. FONPs can be classified as a semiconductor material (with a band gap of ≈0.3 eV), which can be modulated by tuning the nanoparticle diameter [4]. For the magnetite (Fe3O4) material of anti-spinel structure, Fe(II) and Fe(III) of the octahedral position of the crystal

Magnetic field-assisted assembly of iron oxide mesocrystals: a matter of nanoparticle shape and magnetic anisotropy

• Julian J. Brunner,
• Marina Krumova,
• Helmut Cölfen and
• Elena V. Sturm (née Rosseeva)

Beilstein J. Nanotechnol. 2019, 10, 894–900, doi:10.3762/bjnano.10.90

• driven by competing of two types of anisotropic interactions caused by particle shape (i.e., faceting) and orientation of the magnetic moment (i.e., easy axes: <111>magnetite). Hence, these findings provide a fundamental understanding of formation mechanisms and structuring of mesocrystals built up from

• superparamagnetic nanoparticles and how a magnetic field can be used to design anisotropic mesocrystals with different structures. Keywords: directed assembly; magnetite; mesocrystal; nanoparticle; transmission electron microscopy; Findings In materials science, nanoparticles and their assemblies belong to the

• hot research topics nowadays [1][2][3][4][5][6][7]. One reason is that their properties can strongly differ from the physical and chemical properties of their corresponding bulk material [8][9][10]. As a matter of fact, magnetite bulk single crystals are ferrimagnetic, while magnetite nanocrystals

Tungsten disulfide-based nanocomposites for photothermal therapy

• Tzuriel Levin,
• Hagit Sade,
• Rina Ben-Shabbat Binyamini,
• Maayan Pour,
• Iftach Nachman and
• Jean-Paul Lellouche

Beilstein J. Nanotechnol. 2019, 10, 811–822, doi:10.3762/bjnano.10.81

• magnetite nanoparticles into γ-maghemite (mag) nanoparticles. The cerium ion attaches to the nanoparticle, producing surface defects (an Fe–O–[CeLn] bond is formed). The cerium-doped maghemite nanoparticles are more stable than the non-doped ones, which tend to aggregate. In addition to the stabilization

• . Then, a concentrated (24 wt %) NH4OH solution (750 µL) was added, resulting in the immediate formation of a black precipitate of magnetite (Fe3O4) nanoparticles. Sonication was continued for an additional 10 min. The liquid was decanted with the help of magnetic separation, using a 0.5 T magnet. The

• to the decanted magnetite NPs, followed by the addition of degassed purified water (18 mL). The resulting mixture was ultrasonicated for 30 min under nitrogen using a high-power sonicator, then transferred into 50 mL Amicon® Ultra-15 centrifugal filter tubes (100KD, Millipore, Cork, Ireland). The

Heating ability of magnetic nanoparticles with cubic and combined anisotropy

• Nikolai A. Usov,
• Mikhail S. Nesmeyanov,
• Elizaveta M. Gubanova and
• Natalia B. Epshtein

Beilstein J. Nanotechnol. 2019, 10, 305–314, doi:10.3762/bjnano.10.29

• , Moscow, Russia National Research Nuclear University “MEPhI”, 115409, Moscow, Russia 10.3762/bjnano.10.29 Abstract The low frequency hysteresis loops and specific absorption rate (SAR) of assemblies of magnetite nanoparticles with cubic anisotropy are calculated in the diameter range of D = 20–60 nm

• taking into account both thermal fluctuations of the particle magnetic moments and strong magneto–dipole interaction in assemblies of fractal-like clusters of nanoparticles. Similar calculations are also performed for assemblies of slightly elongated magnetite nanoparticles having combined magnetic

• . However, the ability of magnetic nanoparticle assemblies to generate heat can be improved if the nanoparticles are covered by nonmagnetic shells of appreciable thickness. Keywords: fractal clusters; magnetite nanoparticles; magneto–dipole interaction; numerical simulation; specific absorption rate

Size-selected Fe₃O₄–Au hybrid nanoparticles for improved magnetism-based theranostics

• Maria V. Efremova,
• Yulia A. Nalench,
• Eirini Myrovali,
• Anastasiia S. Garanina,
• Ivan S. Grebennikov,
• Polina K. Gifer,
• Maxim A. Abakumov,
• Marina Spasova,
• Makis Angelakeris,
• Alexander G. Savchenko,
• Michael Farle,
• Natalia L. Klyachko,
• Alexander G. Majouga and
• Ulf Wiedwald

Beilstein J. Nanotechnol. 2018, 9, 2684–2699, doi:10.3762/bjnano.9.251

• and agarose phantom systems) showed the best characteristics for application as contrast agents in magnetic resonance imaging and for local heating using magnetic particle hyperthermia. Due to the octahedral shape and the large saturation magnetization of the magnetite particles, we obtained an

• hyperthermia; magnetic resonance imaging; nanomagnetism; theranostics; Introduction Biocompatible magnetite nanoparticles (NPs) are anticipated to provide new noninvasive therapies and early diagnostics for previously incurable diseases using a single, so-called “theranostics” platform [1][2][3]. The magnetic

• -Fe2O3 and magnetite, to high-quality stoichiometric Fe3O4. We find a size-dependent transition from superparamagnetic to a stable ferrimagnetic response, a bulk-like saturation magnetization, and observe the Verwey transition at 123 K – all of which result in the superior magnetic properties for a

Cytotoxicity of doxorubicin-conjugated poly[N-(2-hydroxypropyl)methacrylamide]-modified γ-Fe₂O₃ nanoparticles towards human tumor cells

• Zdeněk Plichta,
• Yulia Kozak,
• Rostyslav Panchuk,
• Viktoria Sokolova,
• Matthias Epple,
• Lesya Kobylinska,
• Pavla Jendelová and
• Daniel Horák

Beilstein J. Nanotechnol. 2018, 9, 2533–2545, doi:10.3762/bjnano.9.236

• , since they yield hydrophilic particles that are mildly polydisperse and do not need any transfer in water. The advantage of maghemite over magnetite consists in its chemical stability [22]. Moreover, the particles exhibited superparamagnetic behavior as documented in our previous paper [23]. This

Nanocellulose: Recent advances and its prospects in environmental remediation

• Katrina Pui Yee Shak,
• Yean Ling Pang and
• Shee Keat Mah

Beilstein J. Nanotechnol. 2018, 9, 2479–2498, doi:10.3762/bjnano.9.232

• nanocellulose surfaces can improve their function as magnetite-based adsorbents for arsenic removal. It is proven that amino groups accessible for iron coordination result in a larger number of adsorption sites on the nanocellulose surface as compared to MFC. In addition, nanocellulose has also been proposed as

• magnetic field. As a result, magnetic nanomaterials have drawn increasing attention. Nanocellulose incorporated with other magnetic nanomaterials is presented as an excellent composite adsorbent with magnetic properties. For example, a core–shell cellulose magnetite (Fe3O4) polymeric ionic liquid magnetic

• -absorbing materials in order to protect cellulosic fibres from UV bleaching [128]. An et al. [129] claimed that the prepared nano-fibrillated cellulose/magnetite/titanium dioxide nanocomposites had a higher photocatalytic hydrogen generation rate as compared to the nano-fibrillated cellulose/titanium

Synthesis of a MnO₂/Fe₃O₄/diatomite nanocomposite as an efficient heterogeneous Fenton-like catalyst for methylene blue degradation

• Zishun Li,
• Xuekun Tang,
• Kun Liu,
• Jing Huang,
• Yueyang Xu,
• Qian Peng and
• Minlin Ao

Beilstein J. Nanotechnol. 2018, 9, 1940–1950, doi:10.3762/bjnano.9.185

• /diatomite. These peaks match well with the (220), (311), (400), (422), (511) and (440) plane spacings of cubic magnetite (JCPDS file No. 19-0629), suggesting the Fe3O4 nanoparticles are successfully coating the surface of diatomite [21]. In addition, the characteristic peaks of magnetite have a large FWHM

• . However, the original characteristic peaks of magnetite are weakened. This indicates that the nano-MnO2 covering on the Fe3O4/diatomite is of low crystallinity or amorphous. Figure 2 shows the FTIR spectra of purified diatomite, Fe3O4/diatomite and MnO2/Fe3O4/diatomite. The broad peaks at 3400 and 1630 cm

• nanoparticles [28]. The marked lattice fringe spacing of 0.28 nm in the HRTEM images (inset) is corresponding to the (331) planes of cubic magnetite [29]. Figure 4b shows the TEM images of MnO2/Fe3O4/diatomite, the nanoparticles on the surface are fully covered by a layer of rough 3D structured material. As

Magnetic properties of Fe₃O₄ antidot arrays synthesized by AFIR: atomic layer deposition, focused ion beam and thermal reduction

• Juan L. Palma,
• Alejandro Pereira,
• Raquel Álvaro,
• José Miguel García-Martín and
• Juan Escrig

Beilstein J. Nanotechnol. 2018, 9, 1728–1734, doi:10.3762/bjnano.9.164

• .9.164 Abstract Magnetic films of magnetite (Fe3O4) with controlled defects, so-called antidot arrays, were synthesized by a new technique called AFIR. AFIR consists of the deposition of a thin film by atomic layer deposition, the generation of square and hexagonal arrays of holes using focused ion beam

Review on nanoparticles and nanostructured materials: history, sources, toxicity and regulations

• Jaison Jeevanandam,
• Ahmed Barhoum,
• Yen S. Chan,
• Alain Dufresne and
• Michael K. Danquah

Beilstein J. Nanotechnol. 2018, 9, 1050–1074, doi:10.3762/bjnano.9.98

• ]. Generally, biocompatible magnetite (Fe3O4), iron oxide, iron sulfides and maghemite (Fe2O3) are synthesized using magnetotactic bacteria [156][157] that helps in targeted cancer treatment via magnetic hyperthermia, magnetic resonance imaging (MRI), DNA analysis and gene therapy [158]. Moreover, surface

Enzymatically promoted release of organic molecules linked to magnetic nanoparticles

• Chiara Lambruschini,
• Silvia Villa,
• Luca Banfi,
• Fabio Canepa,
• Fabio Morana,
• Annalisa Relini,
• Paola Riani,
• Renata Riva and
• Fulvio Silvetti

Beilstein J. Nanotechnol. 2018, 9, 986–999, doi:10.3762/bjnano.9.92

• Chiara Lambruschini Silvia Villa Luca Banfi Fabio Canepa Fabio Morana Annalisa Relini Paola Riani Renata Riva Fulvio Silvetti Department of Chemistry and Industrial Chemistry, Università di Genova, via Dodecaneso, 31 16146 Genova, Italy 10.3762/bjnano.9.92 Abstract Magnetite-based magnetic

• decided not to bind a real drug, but simply a fluorescent molecule, in order to facilitate analysis of enzymatic cleavage and obtain the first proof of concept of the enzymatic release of a small organic molecule bound to a magnetic nanoparticle. Results and Discussion Magnetite nanoparticles were

• azelate-linked conjugate 13. Figure 3B reports the fluorescence spectra for this compound and for unconjugated 12. Finally, the infrared spectra of both 9 and 13 are reported in Figure 4 and compared with the spectra of NP@APTES and of magnetite. Although a broadening of the peaks is observed, the signals

Heavy-metal detectors based on modified ferrite nanoparticles

• Urszula Klekotka,
• Ewelina Wińska,
• Elżbieta Zambrzycka-Szelewa,
• Dariusz Satuła and
• Beata Kalska-Szostko

Beilstein J. Nanotechnol. 2018, 9, 762–770, doi:10.3762/bjnano.9.69

• Abstract In this work, we analyze artificial heavy-metal solutions with ferrite nanoparticles. Measurements of adsorption effectiveness of different kinds of particles, pure magnetite or magnetite doped with calcium, cobalt, manganese, or nickel ions, were carried out. A dependence of the adsorption

• ] and also magnetic nanoparticles [13][14] usually doped with other elements (e.g., Ca, Mn) [15][16] have been tested for this purpose. Therefore, detailed studies on adsorption efficiency on doped magnetite nanoparticles are very interesting and innovative in order to understand the importance of core

• composition and surface modification. The aim of the study is to examine the efficiency of adsorption of heavy metals in artificial solutions on doped magnetite nanoparticles (Ca, Co, Mn, Ni) surface-modified with PA, SA, AA, 3-PPA or 16-PHDA linkers. Experimental Reagents and solutions Chemicals used in this

Anchoring Fe₃O₄ nanoparticles in a reduced graphene oxide aerogel matrix via polydopamine coating

• Błażej Scheibe,
• Radosław Mrówczyński,
• Natalia Michalak,
• Karol Załęski,
• Michał Matczak,
• Mateusz Kempiński,
• Zuzanna Pietralik,
• Mikołaj Lewandowski,
• Stefan Jurga and
• Feliks Stobiecki

Beilstein J. Nanotechnol. 2018, 9, 591–601, doi:10.3762/bjnano.9.55

• Academy of Sciences, M. Smoluchowskiego 17, 60-179 Poznań, Poland Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland 10.3762/bjnano.9.55 Abstract Reduced graphene oxide–magnetite hybrid aerogels attract great interest thanks to their potential applications, e.g., as

• magnetic actuators. However, the tendency of magnetite particles to migrate within the matrix and, ultimately, escape from the aerogel structure, remains a technological challenge. In this article we show that coating magnetite particles with polydopamine anchors them on graphene oxide defects

• , immobilizing the particles in the matrix and, at the same time, improving the aerogel structure. Polydopamine coating does not affect the magnetic properties of magnetite particles, making the fabricated materials promising for industrial applications. Keywords: aerogel; composite; Fe3O4 nanoparticles

Atomic layer deposition and properties of ZrO₂/Fe₂O₃ thin films

• Kristjan Kalam,
• Helina Seemen,
• Peeter Ritslaid,
• Mihkel Rähn,
• Aile Tamm,
• Kaupo Kukli,
• Aarne Kasikov,
• Joosep Link,
• Raivo Stern,
• Salvador Dueñas,
• Helena Castán and
• Héctor García

Beilstein J. Nanotechnol. 2018, 9, 119–128, doi:10.3762/bjnano.9.14

• Fe2O3 phases do not possess lattice structure, allowing commensurate growth on TiN. The epitaxial relationship between magnetite (Fe3O4) and titanium nitride might be considered [41], but magnetite was not recognized in this study in the XRD patterns and, most importantly, the very first layers

Dynamic behavior of a nematic liquid crystal mixed with CoFe₂O₄ ferromagnetic nanoparticles in a magnetic field

• Emil Petrescu,
• Cristina Cirtoaje and
• Cristina Stan

Beilstein J. Nanotechnol. 2017, 8, 2467–2473, doi:10.3762/bjnano.8.246

• higher Fréedericksz threshold [11][12]. The unique properties of nanoparticles open new development directions not only in materials science, but also in electronics, providing considerable improvement [13]. Liquid crystals, largely used for displays, are now mixed with nanoparticles such as magnetite

Involvement of two uptake mechanisms of gold and iron oxide nanoparticles in a co-exposure scenario using mouse macrophages

• Dimitri Vanhecke,
• Dagmar A. Kuhn,
• Dorleta Jimenez de Aberasturi,
• Sandor Balog,
• Ana Milosevic,
• Dominic Urban,
• Diana Peckys,
• Niels de Jonge,
• Wolfgang J. Parak,
• Alke Petri-Fink and
• Barbara Rothen-Rutishauser

Beilstein J. Nanotechnol. 2017, 8, 2396–2409, doi:10.3762/bjnano.8.239

• ][45], and characterisation are provided in Supporting Information File 1 (Figures S1–S13). Please note that the synthesis protocol employed for the iron oxide NPs has been reported to yield maghemite (γ-Fe2O3), but as no experimental verification was applied to exclude formation of magnetite (Fe3O4

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

• [11][12][13][14]. However, the direct-deposition protocols are mainly suitable for covering γ-Fe2O3 NPs. The formation of a gold shell on magnetite (Fe3O4) or ferrite surfaces through reduction of chloroauric acid by citrates or borohydride is usually problematic due to the formation of pure gold

• attachment of gold species. In recent publications amino acids such as methionine [19] and lysine [24] have been reported to be effective capping agents to control the size of magnetite [19] and Co ferrite [24] NPs during co-precipitation synthesis [25]. The main goal of the methionine capping was the

• specific targeting ligands, such as aptamers and antibodies. This synthesis way may also be explored in future to design superparamagnetic, methionine-stabilized plasmonic magnetite NPs decorated with Au0/Au+1 QDs. Experimental Chemicals: All chemicals, including Co(II) and Fe(III) chlorides, and HAuCl4