pH-Controlled fluorescence switching in water-dispersed polymer brushes grafted to modified boron nitride nanotubes for cellular imaging

• Saban Kalay,
• Yurij Stetsyshyn,
• Volodymyr Donchak,
• Khrystyna Harhay,
• Ostap Lishchynskyi,
• Halyna Ohar,
• Yuriy Panchenko,
• Stanislav Voronov and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2019, 10, 2428–2439, doi:10.3762/bjnano.10.233

• the maximum fluorescein absorption is at 437 nm but in alkaline solution it is at about 490 nm, and the absorption intensity is significantly higher than that of the acidic solution. As seen in the figure, the highest intensity of the absorbance is at 490 nm for pH 10 (Figure 7, green line) and

• slightly less at pH 7–8 (Figure 7, blue and red lines). In contrast, at pH 6 (Figure 7, yellow line) a strongly shifted, small, intense absorbance peak is observed. At pH 4 (Figure 7, green line) the absorbance is very poor, and we can state here that it has no absorbance. Only at pH 2 (Figure 7, brown

Multiwalled carbon nanotube based aromatic volatile organic compound sensor: sensitivity enhancement through 1-hexadecanethiol functionalisation

• Nadra Bohli,
• Meryem Belkilani,
• Juan Casanova-Chafer,
• Eduard Llobet and
• Adnane Abdelghani

Beilstein J. Nanotechnol. 2019, 10, 2364–2373, doi:10.3762/bjnano.10.227

• 1011), operating at 100 kV. An Alpha FTIR spectrometer (Bruker, France) equipped with an ATR platinum crystal diamond module was used, in absorbance mode, to obtain the infrared spectra of the gold-decorated MWCNTs before and after the deposition of the SAM monolayer. This technique provides useful

• performance [25][26]. FTIR characterisation In order to ensure that the HDT monolayers are formed and well immobilized on the Au-MWCNT layers, we used FTIR spectroscopy. Figure 3 shows the infrared spectra, in absorbance mode, of both Au-MWCNT and HDT/Au-MWCNT layers. When analysing and comparing the infrared

Mannosylated brush copolymers based on poly(ethylene glycol) and poly(ε-caprolactone) as multivalent lectin-binding nanomaterials

• Stefania Ordanini,
• Wanda Celentano,
• Anna Bernardi and
• Francesco Cellesi

Beilstein J. Nanotechnol. 2019, 10, 2192–2206, doi:10.3762/bjnano.10.212

• . In the case of the divalent compound PEG8-PCL2-Man2, the absorbance quickly reached a plateau and then remained almost constant, although a stepwise variation of the OD indicated a partial precipitation of the aggregates, as shown in Figure 6B. The same happened for the octavalent glycopolymer A4

Incorporation of doxorubicin in different polymer nanoparticles and their anticancer activity

• Sebastian Pieper,
• Hannah Onafuye,
• Dennis Mulac,
• Jindrich Cinatl Jr.,
• Mark N. Wass,
• Martin Michaelis and
• Klaus Langer

Beilstein J. Nanotechnol. 2019, 10, 2062–2072, doi:10.3762/bjnano.10.201

• ) sodium dodecylsulfate and 50% (v/v) N,N-dimethylformamide (pH 4.7) at 37 °C for 4 h. Absorbance was determined at 570 nm for each well using a 96-well multiscanner. After subtracting of the background absorption, the results are expressed as percentage viability relative to untreated control cultures

Optimization and performance of nitrogen-doped carbon dots as a color conversion layer for white-LED applications

• Tugrul Guner,
• Hurriyet Yuce,
• Didem Tascioglu,
• Eren Simsek,
• Umut Savaci,
• Aziz Genc,
• Servet Turan and
• Mustafa M. Demir

Beilstein J. Nanotechnol. 2019, 10, 2004–2013, doi:10.3762/bjnano.10.197

• -Alpha XPS spectrometer. Fourier-transform infrared spectroscopy (FTIR; Spectrum 100, PerkinElmer, Shelton, CT, USA) was used to characterize the kinetic behavior of the chemical bonds. Photoluminescence (PL) and absorbance were measured using an integrating sphere (ISP-50-80-R, Ocean Optics Inc

Nanostructured and oriented metal–organic framework films enabling extreme surface wetting properties

• Andre Mähringer,
• Julian M. Rotter and
• Dana D. Medina

Beilstein J. Nanotechnol. 2019, 10, 1994–2003, doi:10.3762/bjnano.10.196

• of experiments establishes the pillar-like nanostructured Ni-CAT-1 films as highly efficient, antifog coatings featuring additional desired properties such as light absorbance. Furthermore, it underlines the power of VAC in enabling controlled bottom-up fabrication of MOF films with well-defined

Gold-coated plant virus as computed tomography imaging contrast agent

• Alaa A. A. Aljabali,
• Mazhar S. Al Zoubi,
• Khalid M. Al-Batanyeh,
• Ali Al-Radaideh,
• Mohammad A. Obeid,
• Abeer Al Sharabi,
• Walhan Alshaer,
• Bayan AbuFares,
• Tasnim Al-Zanati,
• Murtaza M. Tambuwala,
• Naveed Akbar and
• David J. Evans

Beilstein J. Nanotechnol. 2019, 10, 1983–1993, doi:10.3762/bjnano.10.195

• increase in the absorbance shift is expected as the SPR of the AuNPs is sensitive to their interparticle distance and surface state [41]. Furthermore, the LSPR band of Au-CPMV is dependent on the size of the particles. The peak absorbance wavelength increases with the increase of the particle diameter as

• together and incubated at 60 °C for 10 min. The samples were left to cool for 30 min and then centrifuged at 14000g for 40 min (Thermo Scientific CL10 Centrifuge) to pellet the particles. The supernatant BCA dye absorbance was measured at λ = 565 nm using a microplate reader. The change in absorbance is a

Preservation of rutin nanosuspensions without the use of preservatives

• Pascal L. Stahr and
• Cornelia M. Keck

Beilstein J. Nanotechnol. 2019, 10, 1902–1913, doi:10.3762/bjnano.10.185

• time in the dark, the absorbance was measured by a UV–vis plate reader (Multiskan GO, Thermo scientific, Germany) at 517 nm. The inhibition activity (inhibition [%]) was calculated as where Asample is the absorbance of the sample and A0 is the absorbance of the control (DPPH solution). The resulting

Engineered superparamagnetic iron oxide nanoparticles (SPIONs) for dual-modality imaging of intracranial glioblastoma via EGFRvIII targeting

• Xianping Liu,
• Chengjuan Du,
• Haichun Li,
• Ting Jiang,
• Zimiao Luo,
• Zhiqing Pang,
• Daoying Geng and
• Jun Zhang

Beilstein J. Nanotechnol. 2019, 10, 1860–1872, doi:10.3762/bjnano.10.181

• ) solution was added to each well. Finally, the absorbance of each well was measured with a microplate reader (Bio-TEK, USA) at a wavelength of 490 nm. To evaluate the in vivo systematic toxicity of PNPs, the histological sections of major organs (e.g., heart, liver, spleen, lung and kidney) were collected

Microfluidic manufacturing of different niosomes nanoparticles for curcumin encapsulation: Physical characteristics, encapsulation efficacy, and drug release

• Mohammad A. Obeid,
• Ibrahim Khadra,
• Abdullah Albaloushi,
• Margaret Mullin,
• Hanin Alyamani and
• Valerie A. Ferro

Beilstein J. Nanotechnol. 2019, 10, 1826–1832, doi:10.3762/bjnano.10.177

• encapsulation efficiency Following removal of the non-encapsulated curcumin by dialysis, 100 µL of each niosome formulation (removed from the dialysis tubing) was lysed with methanol in order to release the encapsulated curcumin, which was then quantified at UV absorbance at 421 nm. The encapsulation efficiency

• preheated at 37 °C. At each time point, the absorbance was measured at 421 nm and the concentration of the released curcumin was determined against a calibration curve. The experiments were performed in triplicate and the mean ± SD is reported. Statistical analysis Statistical significance was assessed by

Toxicity and safety study of silver and gold nanoparticles functionalized with cysteine and glutathione

• Barbara Pem,
• Igor M. Pongrac,
• Lea Ulm,
• Ivan Pavičić,
• Valerije Vrček,
• Darija Domazet Jurašin,
• Marija Ljubojević,
• Adela Krivohlavek and
• Ivana Vinković Vrček

Beilstein J. Nanotechnol. 2019, 10, 1802–1817, doi:10.3762/bjnano.10.175

• shaking the plates. The absorbance was recorded at 530 nm using a VictorTM multilabel reader (Perkin Elmer, Massachusetts, USA). The ratio of live, apoptotic and dead cells after treatment with NPs or respective metal salts was determined by flow cytometry experiments using Annexin V and 7

Biocatalytic oligomerization-induced self-assembly of crystalline cellulose oligomers into nanoribbon networks assisted by organic solvents

• Yuuki Hata,
• Yuka Fukaya,
• Toshiki Sawada,
• Masahito Nishiura and
• Takeshi Serizawa

Beilstein J. Nanotechnol. 2019, 10, 1778–1788, doi:10.3762/bjnano.10.173

• solution containing 10 vol % MeCN or EtOH at a concentration where the absorbance of CDP at 280 nm was 0.1. The CDP solutions were incubated at 60 °C for 6 and 72 h. The CD spectra of the samples were recorded on a J-725 instrument (JASCO) at a path length of 2 mm, a scan rate of 100 nm min−1, and a

Growth dynamics and light scattering of gold nanoparticles in situ synthesized at high concentration in thin polymer films

• Corentin Guyot,
• Philippe Vandestrick,
• Ingrid Marenne,
• Olivier Deparis and
• Michel Voué

Beilstein J. Nanotechnol. 2019, 10, 1768–1777, doi:10.3762/bjnano.10.172

• to aggregate yielding nanoparticles. These steps are enhanced by annealing the films at a temperature higher than the glass transition temperature of the polymer. In practice, the in situ synthesis allowed us to obtain relatively thin films (300–500 nm) with an absorbance equivalent to that measured

• with a “classical” colloidal solution of AuNPs in a cuvette with 1 cm optical path (Figure 1). This means that the same absorbance can be obtained with a material thickness ca. 2·104 times smaller. Passive Q-switches based on saturable absorption of AuNP-doped films are usually prepared in a two-steps

• mass ratio increases, the absorbance reaches an increasing plateau value. Moreover, increasing the annealing temperature increases the reduction kinetics. The plateau value is reached within shorter times. Besides playing a role in the growth kinetics of the nanoparticles by promoting the reduction of

Doxorubicin-loaded human serum albumin nanoparticles overcome transporter-mediated drug resistance in drug-adapted cancer cells

• Hannah Onafuye,
• Sebastian Pieper,
• Dennis Mulac,
• Jindrich Cinatl Jr.,
• Mark N. Wass,
• Klaus Langer and
• Martin Michaelis

Beilstein J. Nanotechnol. 2019, 10, 1707–1715, doi:10.3762/bjnano.10.166

• 20% (w/v) sodium dodecylsulfate and 50% (v/v) N,N-dimethylformamide with the pH adjusted to 4.7 at 37 °C for 4 h. The absorbance was determined at 570 nm for each well using a 96-well multiscanner. After subtracting of the background absorption, the results are expressed as percentage viability

Kelvin probe force microscopy work function characterization of transition metal oxide crystals under ongoing reduction and oxidation

• Dominik Wrana,
• Karol Cieślik,
• Wojciech Belza,
• Christian Rodenbücher,
• Krzysztof Szot and
• Franciszek Krok

Beilstein J. Nanotechnol. 2019, 10, 1596–1607, doi:10.3762/bjnano.10.155

• nanostructures exhibit a strong absorbance of light over a broad spectrum, which is of potential use in novel tumor therapy [19]. In addition, in the previous year, a profound interest was focused on the superconductivity of various TiO structures [20][21]. According to those, rock-salt TiO is a type-II

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

• . At constant intervals of time, samples were taken from the suspension and centrifuged. Then the absorbance of the solution was analyzed at a wavelength of 664 nm. The photocatalytic efficiency of Bi2WO6 was taken calculated as follows: η(%) = (A0 – A)/A0·100%, where A0 and A are the absorbance of MB

• (red) of the SAED pattern, overlaid by a standard PDF card; (d) Absorbance and degradation efficiency as a function of irradiation time, the inset is a photograph of the degradation experiment. Effects of electron-beam irradiation on an individual Bi2WO6 nanoflake observed by using HRTEM. (a–e

BiOCl/TiO₂/diatomite composites with enhanced visible-light photocatalytic activity for the degradation of rhodamine B

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

Beilstein J. Nanotechnol. 2019, 10, 1412–1422, doi:10.3762/bjnano.10.139

• –vis spectra of RhB in the degradation process by BTD. It can be seen that with the increase of illumination time, the absorbance intensity decreases and the peak shifts toward shorter wavelength (blue shift). This is mainly due to de-ethylation of RhB, accompanied by the breakage of aromatic groups

Construction of a 0D/1D composite based on Au nanoparticles/CuBi₂O₄ microrods for efficient visible-light-driven photocatalytic activity

• Weilong Shi,
• Mingyang Li,
• Hongji Ren,
• Feng Guo,
• Xiliu Huang,
• Yu Shi and
• Yubin Tang

Beilstein J. Nanotechnol. 2019, 10, 1360–1367, doi:10.3762/bjnano.10.134

• solution (measured by means of the absorbance at a wavelength of 357 nm). The blank experiment showed that the degradation rate of TC solution under visible-light irradiation is very low, indicating that the self-degradation of TC is negligible (Figure 6a). Pure CBO has a poor photocatalytic activity

A highly efficient porous rod-like Ce-doped ZnO photocatalyst for the degradation of dye contaminants in water

• Binjing Hu,
• Qiang Sun,
• Chengyi Zuo,
• Yunxin Pei,
• Siwei Yang,
• Hui Zheng and
• Fangming Liu

Beilstein J. Nanotechnol. 2019, 10, 1157–1165, doi:10.3762/bjnano.10.115

• centrifuged before this process began. The supernatant was diluted with an equal amount of deionized water, then taken out for the measurement of absorbance (A0) at 554 nm by UV–vis spectroscopy. Every 20 min the sampling process was repeated, and the absorbance was determined. The degradation rate (DR) was

• test tube. The suspension was stirred in darkness for 30 min before the initial absorbance was measured. The degradation rate was calculated after 2 h of exposure to sunlight. The design and results are listed in Table 1. Characterization of photocatalysts The XRD patterns of ZnO and CZO-4 were

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

• the solution (20 μL) was transferred to a 2 mL Eppendorf tube containing water (1.58 mL) and FC reagent (100 μL). Then, 17 wt % sodium carbonate solution (300 μL) was added, and the mixture was vortexed for 140 s and kept in the dark for 1.5 h. Absorbance was measured using a Specord 250Plus UV

• mL Eppendorf tube containing chitosan solution (0.2 mL), and the mixture was vigorously vortexed for 1 min and stored in the dark for 30 min. The absorbance was measured at a wavelength of 517 nm against ethanol using the same spectrometer as above. A mixture of 0.1 mM DPPH (0.6 mL and ethanol (1.4

• mL) served as a control. DPPH inhibition was determined as follows: where A0 and A1 are the absorbance of the control and the sample, respectively. The results from the DPPH assay were expressed as the half maximal inhibitory concentration (IC50), which is the amount of substance required to decrease

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

• directly used to measure the output power, and the other is used to measure the output power after passing through the SA. Figure 2d gives the nonlinear transmission curve of the FONP SA. It can be seen that the saturation absorption intensity, modulation depth, and nonsaturable absorbance are about 12 MW

• FONP powder were measured by UV–vis–NIR spectroscopy, as shown in Figure 3d. From these results, 92% absorbance at 1560 nm can be observed. In Figure 4a–c, the microstructure of the FONP SA is confirmed via scanning electron microscopy (SEM) at the 4, 3 and 1 µm scale, respectively. It can be clearly

Enhanced inhibition of influenza virus infection by peptide–noble-metal nanoparticle conjugates

• Zaid K. Alghrair,
• David G. Fernig and
• Bahram Ebrahimi

Beilstein J. Nanotechnol. 2019, 10, 1038–1047, doi:10.3762/bjnano.10.104

• exert its antiviral activity from the outside of the cell. Thus, the addition of FluPep to cells in culture prevents infection by influenza viruses, as does intranasal delivery of the peptide in a murine model of human influenza [15]. Noble-metal nanoparticles possess a strong plasmon absorbance, which

• allows for the detection at very low levels, using a range of approaches, from absorbance [17][18] to photothermal microscopy [19] and various extensions of the latter [20][21]. Noble-metal nanoparticles can be passivated and functionalised with biomolecules such that they possess the biological

• nanoparticles is at 520 nm. When gold nanoparticles are aggregated, their surface plasmons couple causing a red shift in their plasmon absorbance to approximately 650 nm. The aggregation parameter (AP) was defined as (A650nm − Aref 650nm)/(A520nm−Aref 520), where A650nm and A520nm are the absorbance of gold

Structural and optical properties of penicillamine-protected gold nanocluster fractions separated by sequential size-selective fractionation

• Xiupei Yang,
• Zhengli Yang,
• Fenglin Tang,
• Jing Xu,
• Maoxue Zhang and
• Martin M. F. Choi

Beilstein J. Nanotechnol. 2019, 10, 955–966, doi:10.3762/bjnano.10.96

• AuNCs possess a sharper decrease in absorbance than that of larger ones, from shorter to longer wavelengths, as could be observed in previous work [38][39]. In essence, the large AuNCs produce absorption spectra that have higher absorption than that of the small core nanoclusters. The difference in the

Effects of gold and PCL- or PLLA-coated silica nanoparticles on brain endothelial cells and the blood–brain barrier

• Aniela Bittner,
• Angélique D. Ducray,
• Hans Rudolf Widmer,
• Michael H. Stoffel and
• Meike Mevissen

Beilstein J. Nanotechnol. 2019, 10, 941–954, doi:10.3762/bjnano.10.95

• was removed and the remaining MTT-formazan was dissolved in DMSO (Sigma, Switzerland). Absorbance was measured at 540 nm using a plate reader (Synergy HT, BioTek, Switzerland). Nanoparticle uptake PCL-, PLLA- and Au-NP uptake was investigated using transmission electron microscopy (TEM). PCL- and PLLA

Nanoscale optical and structural characterisation of silk

• Meguya Ryu,
• Reo Honda,
• Adrian Cernescu,
• Arturas Vailionis,
• Armandas Balčytis,
• Jitraporn Vongsvivut,
• Jing-Liang Li,
• Denver P. Linklater,
• Elena P. Ivanova,
• Vygantas Mizeikis,
• Mark J. Tobin,
• Junko Morikawa and
• Saulius Juodkazis

Beilstein J. Nanotechnol. 2019, 10, 922–929, doi:10.3762/bjnano.10.93

• crystalline building blocks of silk. Nanoscale optical and structural properties of silk have been measured from 100 nm thick longitudinal slices of silk fibers with ca. 10 nm resolution, the highest so far. Optical sub-wavelength resolution in hyperspectral mapping of absorbance and molecular orientation

• were carried out for comparison at IR wavelengths of 2–10 μm using synchrotron radiation. A reliable distinction of transmission changes by only 1–2% as the anisotropy of amide bands was obtained from nanometer-thin slices of silk. Keywords: absorbance; anisotropy; retardance; silk; Introduction

• orientation dependency of the birefringence Δn and dichroism Δκ, define the optical response of a material. The reflectance R is proportional to the real part, while the absorbance A corresponds to the imaginary part of . Recently, we demonstrated that the IR measurements of silk performed using three