A review on slip boundary conditions at the nanoscale: recent development and applications

• Ruifei Wang,
• Jin Chai,
• Bobo Luo,
• Xiong Liu,
• Jianting Zhang,
• Min Wu,
• Mingdan Wei and
• Zhuanyue Ma

Beilstein J. Nanotechnol. 2021, 12, 1237–1251, doi:10.3762/bjnano.12.91

• this conclusion was drawn based on an ideal Lennard–Jones fluid. Its applicability on other Newtonian fluids with properties such as polarity and even on non-Newtonian fluids should be further validated. 2.2 Surface charge effects Investigating electrokinetics phenomena, including electro-osmosis

• applied electric field. Due to the surface charge on the solid surface, an electrical double layer (EDL), which is comprised of oppositely charged ions, naturally forms within the liquid in the vicinity of the solid surface. As shown in Figure 5, the EDL consists of an immobile Stern layer and a mobile

• experience a slippage [80]. In addition, the hydrodynamic slippage at the solid–liquid interface can in turn largely enhance the electro-osmotic velocity, which increases the urgency for a deep research on the liquid slippage phenomena in electrokinetics. Owing to the direct influence of surface charge

Morphology-driven gas sensing by fabricated fractals: A review

• Vishal Kamathe and
• Rupali Nagar

Beilstein J. Nanotechnol. 2021, 12, 1187–1208, doi:10.3762/bjnano.12.88

• material upon interaction with target gas analytes arise due to changes in, for instance, energy bands, surface charge, and work function caused by temperature, grain size, crystal plane energies, and doping [87][90][91]. Thus, there is no single sensing mechanism that explains all SMO gas sensors. The

pH-driven enhancement of anti-tubercular drug loading on iron oxide nanoparticles for drug delivery in macrophages

• Karishma Berta Cotta,
• Sarika Mehra and
• Rajdip Bandyopadhyaya

Beilstein J. Nanotechnol. 2021, 12, 1127–1139, doi:10.3762/bjnano.12.84

•  1). The NOR@IONPs also carry a surface charge and neutral pH. Thus indicating that these particles indeed have an improved stability, possibly due to the coating of drug. NOR@IONPpH5 also appear to have a higher drug loading. It was noted that both NOR@IONPpH5 and NOR@IONPpH10 had 2–3 nm larger

• identical treatment conditions (Figure 6a). The increased uptake could be due to active engulfment of nanoparticles by macrophages, due to their larger size (20–120 nm size range) and surface charge (+29 mV or −16.5 mV) [46], which results in simultaneous internalization of larger amounts of drug. Figure 6b

Modification of a SERS-active Ag surface to promote adsorption of charged analytes: effect of Cu²⁺ ions

• Bahdan V. Ranishenka,
• Andrei Yu. Panarin,
• Irina A. Chelnokova,
• Sergei N. Terekhov,
• Peter Mojzes and
• Vadim V. Shmanai

Beilstein J. Nanotechnol. 2021, 12, 902–912, doi:10.3762/bjnano.12.67

• charged hydrophilic thiols (sodium 2-mercaptoethyl sulfonate, mercaptopropionic acid, 2-mercaptoethanol, 2-(dimethylamino)ethanethiol hydrochloride, and thiocholine) to vary the surface charge of the SERS substrate. We used two oppositely charged porphyrins, cationic copper(II) tetrakis(4-N-methylpyridyl

• the surface charge of the substrate, which tends to be negative. Using the data obtained and our model SERS system, we analyzed the modification of the Ag surface by different reagents (lithium chloride, polyethylenimine, polyhexamethylene guanidine, and multicharged metal ions). Finally, all those

• suggest that some negatively charged centers are still present at the NP surfaces after thiocholine modification, such as, for example, adsorbed chloride thiocholine counter ions, which contribute to the resulting surface charge. The experimental data obtained support previous reports about the great

Comprehensive review on ultrasound-responsive theranostic nanomaterials: mechanisms, structures and medical applications

• Sepand Tehrani Fateh,
• Lida Moradi,
• Elmira Kohan,
• Michael R. Hamblin and
• Amin Shiralizadeh Dezfuli

Beilstein J. Nanotechnol. 2021, 12, 808–862, doi:10.3762/bjnano.12.64

Recent progress in actuation technologies of micro/nanorobots

• Ke Xu and
• Bing Liu

Beilstein J. Nanotechnol. 2021, 12, 756–765, doi:10.3762/bjnano.12.59

• conductive materials into a micro/nanorobot and then adjusting the surface charge of the robot or the electrochemical reaction on the interface through electric fields can also yield actuation. Zhang et al. [29] proposed an interdigital microelectrode system. When an AC electric field is applied, metal

Fate and transformation of silver nanoparticles in different biological conditions

• Barbara Pem,
• Marija Ćurlin,
• Darija Domazet Jurašin,
• Valerije Vrček,
• Rinea Barbir,
• Vedran Micek,
• Raluca M. Fratila,
• Jesus M. de la Fuente and
• Ivana Vinković Vrček

Beilstein J. Nanotechnol. 2021, 12, 665–679, doi:10.3762/bjnano.12.53

• medical products may be related to human exposure and safety as AgNPs may undergo complex transformations in biological media [6]. It is well known that AgNP physicochemical characteristics, such as size, shape, surface charge, surface functionalization, or core composition determine their interactions

• such conditions, the repulsive electrostatic forces between particles with the same surface charge are weakened, leading to aggregation upon collision [10]. The AgNPs with bulky coatings are less sensitive to this, since their stabilisation is steric and not electrostatic [14]. The dissolution of AgNPs

• AgNPs in artificial biological media In order to gain more coherent insight into the transformation of different AgNPs in biological media, we examined changes in their size, surface charge, and dissolution in simpler media (i.e., CCM, m(CCM+BSA), mCYS, m(CYS+BSA), mGSH, m(GSH+BSA), ALF, and AGF, see

The preparation temperature influences the physicochemical nature and activity of nanoceria

• Robert A. Yokel,
• Wendel Wohlleben,
• Johannes Georg Keller,
• Matthew L. Hancock,
• Jason M. Unrine,
• D. Allan Butterfield and
• Eric A. Grulke

Beilstein J. Nanotechnol. 2021, 12, 525–540, doi:10.3762/bjnano.12.43

• , compared to 6.5 to 13.2 nm for the as-prepared nanoceria. After 75 days of dissolution, the surface charge was −9 mV, compared to the as-prepared nanoceria surface charge of −40 mV, suggesting the loss of the citrate coating. RAW 264.7 cell exposure to the as-prepared solvothermally synthesized nanoceria

• the exposure to partially dissolved nanoceria may be due to the increased surface content of Ce3+ providing antioxidant potential. After dialysis in water, the partially dissolved nanoceria rapidly precipitates from the dispersion, presumably due to the loss of surface citrate and reduced surface

• charge. The particles do not pass through a 0.2 micrometer MWCO filter, suggesting that they were quite large, which may have affected cell uptake. The results illustrate an effect of nanoceria dissolution on its biological identity. Nanoceria reactivity Nanoceria reactivity increased as the content of

Simulation of gas sensing with a triboelectric nanogenerator

• Kaiqin Zhao,
• Hua Gan,
• Huan Li,
• Ziyu Liu and
• Zhiyuan Zhu

Beilstein J. Nanotechnol. 2021, 12, 507–516, doi:10.3762/bjnano.12.41

• area. Further, in order to eliminate the inevitable topological change during the actual movement of the TENG, an air gap was established in COMSOL to construct the two-dimensional model of the TENG. Based on the assumption that the surface charge density of the triboelectric nanogenerator is constant

• materials approach or move away from each other, other substances, such as water vapor, carbon dioxide, and other gases, can pass through the gap. We present a simulation with water vapor under ideal conditions, that is, the surface charge density may be changed during the experiment. A simplified two

• triboelectric materials is helpful for distinguishing different gases. It is noted that water or humidity can degrade the surface charge density of the electrification surfaces in an actual experiment. We will carry out further investigations in the future. Conclusion Simulations of three differently shaped

A review on nanostructured silver as a basic ingredient in medicine: physicochemical parameters and characterization

• Gabriel M. Misirli,
• Kishore Sridharan and
• Shirley M. P. Abrantes

Beilstein J. Nanotechnol. 2021, 12, 440–461, doi:10.3762/bjnano.12.36

• aggregation, physicochemical or biological synthesis methods used, chemical nature of the coating, surface charge, and free Ag+ content. The quality control of AgNPs is necessary to guarantee their suitability for the intended use, reproducibility, efficacy, and low toxicity [146]. Another important point is

Colloidal particle aggregation: mechanism of assembly studied via constructal theory modeling

• Scott C. Bukosky,
• Sukrith Dev,
• Monica S. Allen and
• Jeffery W. Allen

Beilstein J. Nanotechnol. 2021, 12, 413–423, doi:10.3762/bjnano.12.33

• , as well as the particle size, spacing, and surface charge. As a result, these system parameters can be tuned in order to control the balance between the DLVO forces. Tunability, or the ability to direct the movement and assembly of particles into higher-order structures, is important for a wide

• electrolyte ions arrange near the surface of the particles to form an electric double layer, thus screening the surface charge. The characteristic length or “thickness” of this double layer (which is a function of the ion concentration, I) is known as the Debye length, λD, while the surface charge is

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

• their surface with PSS. The LSPR peak of the PSS-coated GNRs was slightly redshifted to 783 nm (Figure 1c). The shift of the LSPR peak after PSS coating is due to the side-by-side assembly of the PSS-GNRs [27]. The surface charge of the GNRs changed from strongly positive (+42 mV, due to CTAB presence

• concentration of 10 µg/mL and were stirred overnight in the dark at room temperature. Excess drug was removed by centrifugation at 12,000g for 10 min and the pellet was re-dispersed in 2 mL deionized water. UV–vis spectra of DOX-loaded GNRs were scanned at a wavelength range of 400–1100 nm. The surface charge

Differences in surface chemistry of iron oxide nanoparticles result in different routes of internalization

• Barbora Svitkova,
• Vlasta Zavisova,
• Veronika Nemethova,
• Martina Koneracka,
• Miroslava Kretova,
• Filip Razga,
• Monika Ursinyova and
• Alena Gabelova

Beilstein J. Nanotechnol. 2021, 12, 270–281, doi:10.3762/bjnano.12.22

• carrier, are the most frequently used materials for biomedical applications [17][18][19][20]. The impact of the surface chemistry on the mechanism of nanoparticle uptake has not been sufficiently clarified yet. MNPs with comparable basic physicochemical characteristics (e.g., particle size, surface charge

• surface charge), cell membrane properties (fluidity, type of receptors, and receptor density), and cell type [30][31][32]. For biomedical applications, the optimal size of nanocarriers is in the range of 95–200 nm because of the higher accumulation rate in tumors [33][34]. Spherical nanoparticles (NPs) in

Paper-based triboelectric nanogenerators and their applications: a review

• Jing Han,
• Nuo Xu,
• Yuchen Liang,
• Mei Ding,
• Junyi Zhai,
• Qijun Sun and
• Zhong Lin Wang

Beilstein J. Nanotechnol. 2021, 12, 151–171, doi:10.3762/bjnano.12.12

• phenomenon. However, the results were highly controversial [88][89]. Xu et al. [90] have proposed that the quantification of the surface charge density at different temperature values is a critical method for investigating this phenomenon. This can be readily explored as an effective tool to identify the

Fusion of purple membranes triggered by immobilization on carbon nanomembranes

• René Riedel,
• Natalie Frese,
• Fang Yang,
• Martin Wortmann,
• Raphael Dalpke,
• Daniel Rhinow,
• Norbert Hampp and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 93–101, doi:10.3762/bjnano.12.8

• deposited patches primarily prefer uncovered areas. In addition, the PM gets well oriented in an electric field according to its surface charge. Initially, a drop of 5 µL WT PM suspension was attached to the substrate only and was not in contact with the opposite electrode. While the plate distance was kept

Effect of different silica coatings on the toxicity of upconversion nanoparticles on RAW 264.7 macrophage cells

• Cynthia Kembuan,
• Helena Oliveira and
• Christina Graf

Beilstein J. Nanotechnol. 2021, 12, 35–48, doi:10.3762/bjnano.12.3

• surface charge [51]. Positively charged silica particles interact more efficiently with the negatively charged cell membrane than negatively charged particles [45], which can also cause an enhanced uptake [51][52]. This process is supported by the fact that the hydrodynamic diameter of the AHAPS

• Table 1. The dispersion behavior and changes in the surface charge of the samples in various media (ethanol, water, and Dulbecco's Modified Eagle Medium (DMEM) supplemented with 10% fetal bovine serum (FBS), 1% glutamine, 1% fungizone, and 1% penicillin) were studied by conducting DLS and ELS

• measurements. The DLS and ZP results are also shown in Table 1. The zeta potential changed from negative to positive after AHAPS functionalization due to the positive surface charge of the amine group in the AHAPS ligand. The zeta potential values of the AHAPS-functionalized samples slightly decreased after

Unravelling the interfacial interaction in mesoporous SiO₂@nickel phyllosilicate/TiO₂ core–shell nanostructures for photocatalytic activity

• Bridget K. Mutuma,
• Xiluva Mathebula,
• Isaac Nongwe,
• Bonakele P. Mtolo,
• Boitumelo J. Matsoso,
• Rudolph Erasmus,
• Zikhona Tetana and
• Neil J. Coville

Beilstein J. Nanotechnol. 2020, 11, 1834–1846, doi:10.3762/bjnano.11.165

• factor that affects the photocatalytic activity of TiO2, is its adsorption capacity for dye molecules. The adsorption capacity of TiO2 can be readily improved by modifying its surface charge density or by increasing its surface area and pore volume [5][20][21]. Further, SiO2 is a good adsorptive material

Nanocasting synthesis of BiFeO₃ nanoparticles with enhanced visible-light photocatalytic activity

• Thomas Cadenbach,
• Maria J. Benitez,
• A. Lucia Morales,
• Cesar Costa Vera,
• Luis Lascano,
• Francisco Quiroz,
• Alexis Debut and
• Karla Vizuete

Beilstein J. Nanotechnol. 2020, 11, 1822–1833, doi:10.3762/bjnano.11.164

• dye, as well as the surface-charge properties of the catalyst. For instance, at neutral pH values RhB is characterized by a zwitter ionic state, whereas it forms a cationic species upon protonation of a carboxylic group at pH values below its pKS2 value of 3.22. Under basic reaction conditions BiFeO3

Mapping of integrated PIN diodes with a 3D architecture by scanning microwave impedance microscopy and dynamic spectroscopy

• Rosine Coq Germanicus,
• Peter De Wolf,
• Florent Lallemand,
• Catherine Bunel,
• Serge Bardy,
• Hugues Murray and
• Ulrike Lüders

Beilstein J. Nanotechnol. 2020, 11, 1764–1775, doi:10.3762/bjnano.11.159

• (including native oxides and surface charge effects). However, the sMIM-C results show a very good signal contrast for both p-type and n-type semiconductors at different levels as well as for lightly doped layers, metallic contacts, oxides, and thin dielectric layers. Therefore, the sMIM methodology provides

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

• NPs. CTAB has a positive surface charge [36], and CTAB molecules accumulated on the surfaces of the Ag2S NPs and repelled other Ag2S NPs due to the mobile electronic charges in Ag2S (negative surface charge). The FTIR spectra of the Ag2S NPs prepared with and without the CTAB surfactant measured in

Optically and electrically driven nanoantennas

• Monika Fleischer,
• Dai Zhang and
• Alfred J. Meixner

Beilstein J. Nanotechnol. 2020, 11, 1542–1545, doi:10.3762/bjnano.11.136

• large surface charge oscillations on the opposite surfaces confining the gap, and a field in the gap that is enhanced by several orders of magnitude with respect to the incident field [27]. The gap field is particularly strong when the particle plasmons are in resonance. The enhanced local field and the

Applications of superparamagnetic iron oxide nanoparticles in drug and therapeutic delivery, and biotechnological advancements

• Maria Suciu,
• Corina M. Ionescu,
• Alexandra Ciorita,
• Septimiu C. Tripon,
• Dragos Nica,
• Hani Al-Salami and
• Lucian Barbu-Tudoran

Beilstein J. Nanotechnol. 2020, 11, 1092–1109, doi:10.3762/bjnano.11.94

• negatively charged SPIONs [57], together with other weak binding proteins, i.e., mannose-binding lectin and their associated serine proteases, apolipoproteins, beta-2 glycoprotein, and clotting factors FXI and FXII. SPIONs with no surface charge have no proteins adsorbed onto them [58][59]. These

• biological applications are synthesized with biocompatible coatings. This coating is very important as its chemical composition determines the way a cell responds to the nanoparticle contact. The coating may or may not have a surface charge that faces the surrounding media, and molecular components from the

• interaction with cells depend on surface charge and zeta potential. A higher zeta potential (positive or negative) leads to more stable and dispersed particles in the colloid [76][91]. Positively charged particles tend to stick to the cell surfaces (which have a negatively charged outer layer in general) and

Adsorptive removal of bulky dye molecules from water with mesoporous polyaniline-derived carbon

• Hyung Jun An,
• Jong Min Park,
• Nazmul Abedin Khan and
• Sung Hwa Jhung

Beilstein J. Nanotechnol. 2020, 11, 597–605, doi:10.3762/bjnano.11.47

• on pH, since the surface charge of porous carbon generally decreases (from positive to negative) with increasing pH of the adsorption solution [61][62][63]. Therefore, the negative AR1 should have a favorable interaction at low pH; on the contrary, the adsorption of the positive JGB will be more

Identification of physicochemical properties that modulate nanoparticle aggregation in blood

• Ludovica Soddu,
• Duong N. Trinh,
• Eimear Dunne,
• Dermot Kenny,
• Giorgia Bernardini,
• Ida Kokalari,
• Arianna Marucco,
• Marco P. Monopoli and
• Ivana Fenoglio

Beilstein J. Nanotechnol. 2020, 11, 550–567, doi:10.3762/bjnano.11.44

• activation of some factors by surface-driven exposure of cryptic domains following adsorption was reported in some studies [5][6]. Other studies have reported the NPs ability to damage or activate platelets, endothelial cells or monocytes [4]. Some physicochemical properties, including the surface charge and

• comparison, therefore, excludes surface charge and hydrophilicity as variables to be investigated. In Figure 12 we summarise the strategy used to unravel possible SARs. This strategy allowed us to identify the surface chemistry as the key factor in the protein corona composition while both surface chemistry

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

• reversal of the surface charge [3]. The coated templates are then rinsed and dipped in a solution of oppositely charged polymer; again, a monolayer deposition takes place but with the restoration of the original surface charge. The rinsing step becomes important, as it would otherwise lead to complex