New application of bimetallic Ag/Pt nanoplates in a colorimetric biosensor for specific detection of E. coli in water

• Azam Bagheri Pebdeni,
• Mohammad N. AL-Baiati and
• Morteza Hosseini

Beilstein J. Nanotechnol. 2024, 15, 95–103, doi:10.3762/bjnano.15.9

• acid solution was gradually added to a stirred mixture of sodium citrate and AgNO3. The purple Ag seed solution was then obtained. In addition, 10 mL of 0.05 M AgNO3 aqueous solution was mixed with 20 mL of 0.1 M hexadecyltrimethylammonium bromide (CTAB) aqueous solution. Slowly, 10 mL of 0.1 M

• ascorbic acid and 0.408 mL of the prepared Ag seed solution were dropped into the CTAB aqueous solution. The Ag nanotemplates were circular. After adding 0.8 mL of 2 M NaOH aqueous solution, the circular Ag nanotemplates were prepared. To lessen the interaction of free CTAB with the synthesis of the

Plasmonic nanotechnology for photothermal applications – an evaluation

• A. R. Indhu,
• L. Keerthana and
• Gnanaprakash Dharmalingam

Beilstein J. Nanotechnol. 2023, 14, 380–419, doi:10.3762/bjnano.14.33

Concentration-dependent photothermal conversion efficiency of gold nanoparticles under near-infrared laser and broadband irradiation

• Vikas,
• Raj Kumar and
• Sanjeev Soni

Beilstein J. Nanotechnol. 2023, 14, 205–217, doi:10.3762/bjnano.14.20

• irradiation power values. Experimental Nanoparticles Gold nanospheres of 40 nm diameter (product no. 741981) and GNRs of 25 × 47 nm size (product no. 771651) were purchased from Sigma-Aldrich. GNRs of 10 × 38 nm size (product no. A12-10-780-CTAB-DIH-1-25) and GNRs of 10 × 41 nm size (product no. A12-10-808

• -CTAB-DIH-1-25) were purchased from Nanopartz Inc. Suspensions with different concentrations of these GNPs were prepared by using ultrapure water (18.1 MΩ resistivity). Plasmonic photothermal measurements The photothermal experiments were performed by adding a 1.5 mL volume of different GNP

A new method for obtaining the magnetic shape anisotropy directly from electron tomography images

• Cristian Radu,
• Ioana D. Vlaicu and
• Andrei C. Kuncser

Beilstein J. Nanotechnol. 2022, 13, 590–598, doi:10.3762/bjnano.13.51

• nanoparticle system. Experimental For the preparation of the magnetite MNPs, the following starting materials were used as purchased: FeSO4·7H2O (Merck, 99.5%), hexadecyltrimethylammonium bromide (CTAB, 99+%, Acros Organics), NaOH (puriss p.a., ACS reagent, reag. Ph. Eur., K < 0.02%, ≥98%, pellets), NH4OH (for

• analysis, 28–30 wt % solution of NH3 in water, Acros Organics). The preparation of the MNPs was performed by reverse precipitation, in which an aqueous solution (50 mL) of FeSO4 with the surfactant CTAB (2:1, mass ratio) was slowly dripped into a 50 mL basic solution of NaOH and NH4OH. The solution turned

Tin dioxide nanomaterial-based photocatalysts for nitrogen oxide oxidation: a review

• Viet Van Pham,
• Hong-Huy Tran,
• Thao Kim Truong and
• Thi Minh Cao

Beilstein J. Nanotechnol. 2022, 13, 96–113, doi:10.3762/bjnano.13.7

• , nanobelts, and nanotubes. These morphologies can be controllably obtained by using polyvinylpyrrolidone (PVP), sodium dodecyl sulfonate (SDS), cetyl trimethyl ammonium bromide (CTAB), or tetrapropyl ammonium bromide (TPAB) as surfactants in a hydrothermal method [56][57][58][59]. The difference of

The role of deep eutectic solvents and carrageenan in synthesizing biocompatible anisotropic metal nanoparticles

• Nabojit Das,
• Akash Kumar and
• Raja Gopal Rayavarapu

Beilstein J. Nanotechnol. 2021, 12, 924–938, doi:10.3762/bjnano.12.69

• nanoparticles, especially rod-shaped gold nanoparticles. The most approved and widely used surfactants for synthesizing anisotropic nanoparticles are quaternary ammonium surfactants with halides (bromide, chloride, or iodide) as counterions. Hexadecyltrimethylammonium bromide (CTAB) is the most commonly used

• maintaining high yield and monodispersity. Initially, gold nanorods were synthesized using electrochemical methods using polycarbonate membrane templates or porous alumina for shape control in the presence of surfactants (mostly CTAB) [34][35]. Because of their optical properties, gold nanorods became

• (NaBH4). Although, seedless synthesis of anisotropic plasmonic metal nanoparticles has been reported, they involved binary surfactants for tuning the absorption spectrum [40]. Apart from CTAB, several other quaternary ammonium surfactants such as myristyltrimethylammonium bromide (MTAB

Rapid controlled synthesis of gold–platinum nanorods with excellent photothermal properties under 808 nm excitation

• Jialin Wang,
• Qianqian Duan,
• Min Yang,
• Boye Zhang,
• Li Guo,
• Pengcui Li,
• Wendong Zhang and
• Shengbo Sang

Beilstein J. Nanotechnol. 2021, 12, 462–472, doi:10.3762/bjnano.12.37

• or presence of Ag+ in the solution were achieved by centrifugation or keeping the Ag+ ions in freshly prepared AuNRs solutions, respectively. When Ag+ was removed, CTAB and K2PtCl4 were added to the cleaned AuNRs solution with an optical density (OD) of 1.5. Please note that the AgNO3 solution was

• Figure 1d and Table 1. Grzelczak et al. proposed an electric field-directed mechanism to explain this phenomenon [27]. The concentration of CTAB in the reaction solution was 8.8 mM. This is much higher than the critical micelle constant (1.04–1.41 mM) of CTAB at this temperature [29][30][31], thus CTAB

• micelles were formed in the solution. PtCl42− is complexed with CTAB micelles and then gets reduced at the surface of AuNRs by ascorbic acid. During the reaction, a relatively obvious Pt shell formed gradually. In sharp contrast, in the presence of Ag+, it is apparent that Pt grows mainly at the tip of the

Doxorubicin-loaded gold nanorods: a multifunctional chemo-photothermal nanoplatform for cancer management

• Uzma Azeem Awan,
• Abida Raza,
• Shaukat Ali,
• Rida Fatima Saeed and
• Nosheen Akhtar

Beilstein J. Nanotechnol. 2021, 12, 295–303, doi:10.3762/bjnano.12.24

• treatments. Regardless of the various beneficial properties, GNRs have limitations in clinical applications due to the cytotoxicity of the surfactant cetyltrimethylammonium bromide (CTAB), which acts as a template in the synthesis process of GNRs [17]. Different polymers can be used to coat GNRs to enhance

• their biocompatibility and dispersion at physiological pH values. The positive CTAB layer on the GNR surface facilitates electrostatic adsorption of anionic compounds, such as poly(sodium 4-styrenesulfonate) (PSS), which ultimately facilitates electrostatic interaction with cationic anticancerous drugs

• ]. The uniform GNRs were synthesized with an aspect ratio of 4.3 (26 ± 2 nm in length and 6 ± 3 nm in width), by keeping pH value (pH 3) and temperature (T = 28 °C) constant. The prepared GNR suspension has a surplus of cytotoxic CTAB, which was removed by repetitive cycles of centrifugation and re

A review on the green and sustainable synthesis of silver nanoparticles and one-dimensional silver nanostructures

• Sina Kaabipour and
• Shohreh Hemmati

Beilstein J. Nanotechnol. 2021, 12, 102–136, doi:10.3762/bjnano.12.9

High-responsivity hybrid α-Ag₂S/Si photodetector prepared by pulsed laser ablation in liquid

• Raid A. Ismail,
• Hanan A. Rawdhan and
• Duha S. Ahmed

Beilstein J. Nanotechnol. 2020, 11, 1596–1607, doi:10.3762/bjnano.11.142

• ) mixed with cationic cetyltrimethylammonium bromide (CTAB) as surfactant. The effect of the CTAB surfactant on the structural, morphological, optical, and elemental composition of Ag2S NPs was evaluated using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy

• (SEM), energy-dispersive X-ray spectroscopy (EDX), and UV–vis spectroscopy. The optical absorption decreased and the optical energy gap of α-Ag2S increased from 1.5 to 2 eV after the CTAB surfactant was added to the Tu solution. XRD studies revealed that the synthesized Ag2S NPs were polycrystalline

• with a monoclinic structure and that crystallinity of the nanoparticles was improved after adding CTAB. Raman studies revealed the presence of peaks related to Ag–S bonds (Ag modes) and the longitudinal optical phonon 2LO mode. Scanning electron microscopy investigations confirmed the production of

Direct observation of oxygen-vacancy formation and structural changes in Bi₂WO₆ nanoflakes induced by electron irradiation

• Hong-long Shi,
• Bin Zou,
• Zi-an Li,
• Min-ting Luo and
• Wen-zhong Wang

Beilstein J. Nanotechnol. 2019, 10, 1434–1442, doi:10.3762/bjnano.10.141

• of deionized water, 0.97 g (0.002 mol) Bi(NO3)3·5H2O, 0.15 g cetyltrimethylammonium bromide (CTAB), and 0.33 g (0.001 mol) Na2WO4·2H2O were added successively under magnetic stirring at room temperature to yield the precursor suspension. The precursor suspension was further transferred into a Teflon

Highly ordered mesoporous silica film nanocomposites containing gold nanoparticles for the catalytic reduction of 4-nitrophenol

• Mohamad Azani Jalani,
• Leny Yuliati,
• Siew Ling Lee and
• Hendrik O. Lintang

Beilstein J. Nanotechnol. 2019, 10, 1368–1379, doi:10.3762/bjnano.10.135

• , good thermal stability, high uniformity, and controllable pore size [1]. These nanomaterials with a hexagonal structure were independently discovered using a layered silicate kanemite as a template to form folded sheet materials (FSM)-16 [14] and cetyltrimethylammonium bromide (CTAB) as a cationic

Polydopamine-coated Au nanorods for targeted fluorescent cell imaging and photothermal therapy

• Boris N. Khlebtsov,
• Andrey M. Burov,
• Timofey E. Pylaev and
• Nikolai G. Khlebtsov

Beilstein J. Nanotechnol. 2019, 10, 794–803, doi:10.3762/bjnano.10.79

• fluids because of a cetyltrimethylammonium bromide (CTAB) bilayer on the AuNR surface, which is a necessary agent in the synthesis method [16]. The coating of the nanoparticles with polymeric or inorganic shells and further functionalization with target molecules can help to overcome this drawback

• transversal and longitudinal plasmonic peak intensities is 3.6, which is indicative to small amount of impurities in the AuNR sample. The adsorption of positively charged CTAB molecules on AuNR surface prevents a successful adsorption of dopamine. To make a PDA coating feasible, the CTAB molecules were

• replaced with the thiolated polyethylene glycol (PEG-SH) as the latter molecules interact more strongly with the Au surface. Without this intermediate procedure, the adsorption of dopamine on CTAB-stabilized AuNRs resulted in nanoparticle aggregation. The formation of the PDA coating can be easily induced

Self-assembly and wetting properties of gold nanorod–CTAB molecules on HOPG

• Imtiaz Ahmad,
• Floor Derkink,
• Tim Boulogne,
• Pantelis Bampoulis,
• Harold J. W. Zandvliet,
• Hidayat Ullah Khan,
• Rahim Jan and
• E. Stefan Kooij

Beilstein J. Nanotechnol. 2019, 10, 696–705, doi:10.3762/bjnano.10.69

• , University of Peshawar, Khyber Pakhtunkhwa 25120, Pakistan School of Chemical and Materials Engineering, National University of Sciences and Technology, Islamabad 44000, Pakistan 10.3762/bjnano.10.69 Abstract The formation of self-assembled superstructures of cetyltrimethylammonium bromide (CTAB) after

• drying on a nonwetting highly ordered pyrolytic graphite (HOPG) surface have been investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Although SEM did not reveal coverage of CTAB layers, AFM showed not only CTAB assembly, but also the dynamics of the process on the

• surface. The self-assembled layers of CTAB molecules on the HOPG terraces prior to nanorod deposition were shown to change the wettability of the surface, and as a result, gold nanorod deposition takes place on nonwetting HOPG terraces. Keywords: CTAB; gold nanorods; micelles; self-assembly; wettability

Surface plasmon resonance enhancement of photoluminescence intensity and bioimaging application of gold nanorod@CdSe/ZnS quantum dots

• Siyi Hu,
• Yu Ren,
• Yue Wang,
• Jinhua Li,
• Junle Qu,
• Liwei Liu,
• Hanbin Ma and
• Yuguo Tang

Beilstein J. Nanotechnol. 2019, 10, 22–31, doi:10.3762/bjnano.10.3

• and biophotonics applications. Experimental Materials and instrumentation Hexadecyltrimethylammonium bromide (CTAB, >98.0%), L-ascorbic acid (BioUltra, ≥99.5%), silver nitrate (AgNO3, >99%), gold(III) chloride trihydrate (HAuCl4·3H2O, 99%), 3-mercaptopropionic acid (MPA, ≥99%), N-ethyl-N'-(3

• prepared by drop casting the sample dispersion onto an amorphous carbon-coated 300 mesh copper grid. Synthesis of GNRs To synthesize the GNRs, the seed-mediated growth method in CTAB solution was applied, as previously discussed [30][31]. The seed solution was prepared using 5 mL of a 0.2 M CTAB solution

• and 5 mL of 0.1 mM HAuCl4. Following this, 0.6 mL of ice-cold 0.01 M NaBH4 solution was quickly added to the HAuCl4− CTAB solution and vigorously stirred for 3–5 min. This caused the solution color to change from yellow to light brown. The solution was stored at 37 °C for 30 min before use. The growth

Graphene-enhanced metal oxide gas sensors at room temperature: a review

• Dongjin Sun,
• Yifan Luo,
• Marc Debliquy and
• Chao Zhang

Beilstein J. Nanotechnol. 2018, 9, 2832–2844, doi:10.3762/bjnano.9.264

• active sites. Meng and co-workers [81] published an inspiring study, where they develop a microwave-assisted hydrothermal technique to grow CuO rods in GO suspension using cetyltrimethylammonium bromide (CTAB) as a soft template. The Cu2O nanorods–rGO hybrids obtained after annealing showed a porous

Cyclodextrin-assisted synthesis of tailored mesoporous silica nanoparticles

• Fuat Topuz and
• Tamer Uyar

Beilstein J. Nanotechnol. 2018, 9, 693–703, doi:10.3762/bjnano.9.64

• bromide (CTAB). Rod-like MSNs were synthesized by using Pluronic 123, a copolymer of ethylene and propylene oxides as porogen additive in the presence of NH4F and heptane [14]. The length and width of such particles could be tuned by addition of HCl. Likewise, Oden and co-workers reported a morphological

• structures were produced using a combination of CTAB surfactant, ethylene glycol solvent and NH4OH as the catalyst. MSNs were also reported in branched forms using organosilane precursors in a one-pot, CTAB-directed sol–gel synthesis [17]. For such a system, increasing the ethyl acetate concentration led to

• injection of tetramethoxysilane (TMOS) and the template molecule n-dodecylamine into the reaction system [18]. Likewise, stearylamine, which has one less alkyl group relative to CTAB, was used as the surfactant to generate microporous silica particles [19]. On the other hand, without the requirement of a

Facile phase transfer of gold nanorods and nanospheres stabilized with block copolymers

• Yaroslav I. Derikov,
• Georgiy A. Shandryuk,
• Raisa V. Talroze,
• Alexander A. Ezhov and
• Yaroslav V. Kudryavtsev

Beilstein J. Nanotechnol. 2018, 9, 616–627, doi:10.3762/bjnano.9.58

• nanorods depend on the refractive index of a medium bordering the nanorod surface. The effect is more pronounced for the TM mode. As shown in [47], in hydrosols, CTAB forms a 4–5 nm bilayer at the surface of Au nanoparticles. The optical dispersion curves for the substances relevant to this study are

• presented in Figure 3. For the sodium D-line, the refractive index of CTAB equals 1.4350 [48], which is close to 1.4440 for chloroform [49], but markedly different from 1.3333 for water [43], 1.4956 for benzene [44], 1.4920 for toluene [44], 1.5915 for polystyrene [50] and 1.622 for poly(2-vinylpyridine) at

• 436 nm [51]. Thus, the presence of a CTAB bilayer at the Au nanorod surface should noticeably shift the maximum position of the TM plasmon resonance in water and benzene. This can be checked by simulations for a model in which a single nanorod is coated with a surface layer with the refractive index

The role of ligands in coinage-metal nanoparticles for electronics

• Ioannis Kanelidis and
• Tobias Kraus

Beilstein J. Nanotechnol. 2017, 8, 2625–2639, doi:10.3762/bjnano.8.263

• initial nucleation processes of particle synthesis; this is probably the mechanism of the formation of ultrathin gold nanowires [64]. Silver nanoparticle synthesis by reduction of silver salts is an important case of ligand-directed nanoparticle growth. Cetyltrimethylammonium bromide (CTAB, Figure 2) in

• combination with ascorbic acid and spherical silver seeds yielded rod-like structures in water by reduction of AgNO3. Jana, Gearheart, and Murphy suggested that CTAB forms micellar templates for the anisotropic growth of nanostructures [65]. Recent studies modified this picture and indicated that CTAB

• formation of gold nanorods with controllable aspect ratios. In the presence of CTAB alone, rods with a broad size distribution formed (see above [65]) in a mixture with other shapes. An improved protocol with a binary surfactant mixture of CTAB and sodium oleate led to gold nanorods with a narrower size

Synthesis and characterization of noble metal–titania core–shell nanostructures with tunable shell thickness

• Bartosz Bartosewicz,
• Marta Michalska-Domańska,
• Malwina Liszewska,
• Dariusz Zasada and
• Bartłomiej J. Jankiewicz

Beilstein J. Nanotechnol. 2017, 8, 2083–2093, doi:10.3762/bjnano.8.208

• the latter approach, control over the shape and size of the synthesized particles is limited. The metal nanoparticles were stabilized before the coating step using various surfactants or stabilizing agents such as Lutensol ON50 [21], cetyltrimethylammonium bromide (CTAB) [27][28][29][30][40], anionic

Fabrication of hierarchically porous TiO₂ nanofibers by microemulsion electrospinning and their application as anode material for lithium-ion batteries

• Jin Zhang,
• Yibing Cai,
• Xuebin Hou,
• Xiaofei Song,
• Pengfei Lv,
• Huimin Zhou and
• Qufu Wei

Beilstein J. Nanotechnol. 2017, 8, 1297–1306, doi:10.3762/bjnano.8.131

• acid and cetyltrimethylammonium bromide (CTAB) were supplied by Shanghai Chemical Regents Co. (Shanghai, China). Additionally, polyvinyl pyrrolidone (PVP) (Mw = 1300000) was purchased from Tianjin Bodi Chemical Reagent Co., Ltd. (Tianjin, China). All chemicals were used as received without further

• purification. Preparation of the spinning solution 0.5 g PVP and 0.3 g CTAB were firstly dissolved into 6.5 g ethanol and 0.4 g acetic acid followed by vigorously stirring to form a homogeneous solution. Subsequently, 1 g paraffin oil and stoichiometric amounts of TBT with different TBT/paraffin oil ratios (w

Selective detection of Mg²⁺ ions via enhanced fluorescence emission using Au–DNA nanocomposites

• Tanushree Basu,
• Khyati Rana,
• Niranjan Das and
• Bonamali Pal

Beilstein J. Nanotechnol. 2017, 8, 762–771, doi:10.3762/bjnano.8.79

• AuNPs. The TEM images of AuNSs and AuNRs are shown in Figure 3, which reveal the formation of Au–DNA NCs [29]. These AuNSs were found to be separated from each other due to the CTAB coating on their surface, which renders them to have a positive charge [30]. The dynamic light scattering (DLS) results

• propionic acid (MPA). The synthesized AuNSs had a CTAB coating and were positively charged in nature. The values obtained for the zeta potential, conductance and mobility are summarized in Supporting Information File 1, Table S2. In Figure 7, the zeta potential is given before binding with DNA for bare

• bromide (CTAB) and DL-dithiothreitol solution (DTT) were purchased from Sigma Aldrich. Sodium borohydride (NaBH4) and silver nitrate (AgNO3) were purchased from Rankem and Fisher Scientific, respectively. Chloroauric acid (HAuCl4·H2O), ascorbic acid, mercaptopropionic acid (MPA) and magnesium acetate (Mg

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

• length influences CNT toxicity and cellular uptake [22][23]. Surfactants commonly used for dispersion of CNTs include SDS, CTAB, Triton X-100 or sodium cholate [24][25][26]. A less known approach is based on the interaction of CNTs with a bis-azo dye – Congo red (CR) [27]. This original procedure was

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

• the GNR surfaces after binding of anti-IgG. The four modified anti-IgG all induced a decrease in zeta potential after conjugation. This is consistent with previously reported observations that GNR surface potentials decrease after bioconjugation from highly positive surface charges packed with CTAB, a

• cationic surfactant bilayer [17][24], because of the replacement of CTAB by thiolated anti-IgG [17][25]. Anti-IgG were detected in thiolation and nanoconjugates with GNRs, but not in free GNRs, by gel electrophoresis followed by Coomassie brilliant blue staining (Figure S1, Supporting Information File 1

Nanoscale isoindigo-carriers: self-assembly and tunable properties

• Tatiana N. Pashirova,
• Andrei V. Bogdanov,
• Lenar I. Musin,
• Julia K. Voronina,
• Irek R. Nizameev,
• Marsil K. Kadirov,
• Vladimir F. Mironov,
• Lucia Ya. Zakharova,
• Shamil K. Latypov and
• Oleg G. Sinyashin

Beilstein J. Nanotechnol. 2017, 8, 313–324, doi:10.3762/bjnano.8.34

• , respectively, two times and 20 times higher than that of the classical surfactants, CTAB and SDS. Fluorescence studies showed that significant changes occur in the pyrene spectrum of the isoindigo derivatives in solution for all the compounds under study, regardless the length of the alkyl chain (Figure 4b

• available classical anionic (SDS), cationic (CTAB) and nonionic (Tween 80) surfactants. Because isatin and isoindigo derivatives are new dyes, their extinction coefficients were determined for the first time. UV–vis absorption spectra of 2a–h and 3 in chloroform are presented in Figures S11–S18 (Supporting

• of that of isoindigo 2a. The solubilization of compound 3 is observed in micellar solutions of CTAB and Tween 80 (Figure S23 and Figure S24, Supporting Information File 1). It is noteworthy that apart from the solubilization mechanism by typical interaction between surfactants and dyes, mixed