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A precise description of the thermodynamic states of gaseous and solid detonation products is essential when using thermodynamic calculations to determine the detonation performance and destructive power of explosives. For high oxygen-lean explosives (the oxygen contained in explosives is insufficient to completely oxidize combustible elements and excess solid carbon will be generated in the detonation products), the phase state of solid carbon product affects the Chapman–Jouguet (CJ) detonation performance parameters, reaction zone, and energy release process. However, the recovery of detonation products demonstrates that the actual detonation carbon product is primarily a mixed state of diamond/graphite stack, as opposed to the existing thermodynamic codes, which essentially treat detonation carbon as single-phase carbon. To understand the thermodynamic effect of the mixed carbon phase state on the non-ideal detonation behavior, in this work, the matching relationship among the VINET equation of state parameters, thermodynamic potential parameters of the solid products of the equivalent system and the phase mixed system was constructed by using the nonlinear fitting method. The relationship between the carbon phase composition at the CJ point and the explosive composition structure was researched. Investigations were conducted into how the mixed carbon phase affected the volume and content of gas products as well as the composition at CJ points. Diamond formation in products is good for enhancing explosive's working capacity. Based on mixed-state potential parameters, the correlation mechanism between the mixed carbon phase and the chemical reaction zone was investigated, and it was found that intramolecular carbon/intermolecular carbon and more detonation graphite/diamond products all would lead to the extension of the reaction zone. [ABSTRACT FROM AUTHOR]

Nitrogen-vacancy (NV-) centers in nanodiamonds have emerged as a versatile platform for a wide range of applications, including bioimaging, photonics, and quantum sensing. However, the widespread adoption of nanodiamonds in practical applications has been hindered by the challenges associated with patterning them into high-resolution features with sufficient throughput. In this work, we overcome these limitations by introducing a direct laser-writing bubble printing technique that enables the precise fabrication of two-dimensional nanodiamond patterns. The printed nanodiamonds exhibit a high packing density and strong photoluminescence emission, as well as robust optically detected magnetic resonance (ODMR) signals. We further harness the spatially resolved ODMR of the nanodiamond patterns to demonstrate the mapping of two-dimensional temperature gradients using high frame rate widefield lock-in fluorescence imaging. This capability paves the way for integrating nanodiamond-based quantum sensors into practical devices and systems, opening new possibilities for applications involving high-resolution thermal imaging and biosensing.

The nitrogen-vacancy (NV) center is a promising candidate to realize practical quantum sensors with high sensitivity and high spatial resolution at room temperature and atmospheric pressure. In conventional high-frequency AC magnetometry with NV centers, the setup requires a pulse sequence with an appropriate time synchronization and strong microwave power. To avoid these practical difficulties, AC magnetometry using continuous-wave optically detected magnetic resonance (CW-ODMR) was recently demonstrated. That previous study utilized radio frequency (RF)-dressed states generated by the coherent interaction between the electron spin of the NV center and the RF wave. However, the drawback of this method is that the detectable frequency of the AC magnetic fields is fixed. Here, we propose and demonstrate frequency-tunable magnetic field sensing based on CW-ODMR. In the new sensing scheme, we obtain RF double-dressed states by irradiation with RF fields at two different frequencies. One creates the RF-dressed states and changes the frequency of the target AC field. The other is a target AC field that induces a change in the CW-ODMR spectrum by generating the RF double-dressed states through coherent interaction with the RF-dressed states. The sensitivity of our method is estimated to be comparable to or even higher than that of the conventional method based on the RF field with a single frequency. The estimated bandwidth is 7.5 MHz, higher than that of the conventional method using the RF-dressed states. Our frequency-tunable magnetic field sensor based on CW-ODMR paves the way for new applications in diamond devices. [ABSTRACT FROM AUTHOR]

We report results on the mechanical and structural response to shear deformation of nanodiamond superstructures in interlayer-bonded twisted bilayer graphene (IB-TBG) and interlayer-bonded graphene bilayers with randomly distributed individual interlayer C–C bonds (RD-IBGs) based on molecular-dynamics simulations. We find that IB-TBG nanodiamond superstructures subjected to shear deformation undergo a brittle-to-ductile transition (BDT) with increasing interlayer bond density (nanodiamond fraction). However, RD-IBG bilayer sheets upon shear deformation consistently undergo brittle failure without exhibiting a BDT. We identify, explain, and characterize in atomic-level detail the different failure mechanisms of the above bilayer structures. We also report the dependence of the mechanical properties, such as shear strength, crack initiation strain, toughness, and shear modulus, of these graphene bilayer sheets on their interlayer bond density and find that these properties differ significantly between IB-TBG nanodiamond superstructures and RD-IBG sheets. Our findings show that the mechanical properties of interlayer-bonded bilayer graphene sheets, including their ductility and the type of failure they undergo under shear deformation, can be systematically tailored by controlling interlayer bond density and distribution. These findings contribute significantly to our understanding of these 2D graphene-based materials as mechanical metamaterials. [ABSTRACT FROM AUTHOR]

[Display omitted] Pre-treatment of diamond surface in low-temperature plasma for oxygenation and in acids for carboxylation was hypothesized to promote the branching density of the hyperbranched glycidol polymer. This was expected to increase the homogeneity of the branching level and suppress interactions with proteins. As a result, composite nanodiamonds with reduced hydrodynamic diameters that are maintained in physiological environments were anticipated. Surfaces of 140-nm-sized nanodiamonds were functionalized with oxygen and carboxyl groups for grafting of hyperbranched dendritic polyglycerol via anionic ring-opening polymerization of glycidol. The modification was verified with Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy. Dynamic light scattering investigated colloidal stability in pH-diverse (2–12) solutions, concentrated phosphate-buffered saline, and cell culture media. Thermogravimetric analysis of nanodiamonds-protein incubations examined non-specific binding. Fluorescence emission was tested across pH conditions. Molecular dynamics simulations modeled interparticle interactions in ionic solutions. The hyperbranched polyglycerol grafting increased colloidal stability of nanodiamonds across diverse pH, high ionic media like 10 × concentrated phosphate-buffered saline, and physiological media like serum and cell culture medium. The hyperbranched polyglycerol suppressed non-specific protein adsorption while maintaining intensive fluorescence of nanodiamonds regardless of pH. Molecular modelling indicated reduced interparticle interactions in ionic solutions correlating with the improved colloidal stability. [ABSTRACT FROM AUTHOR]

Aim Methodology Results Conclusions To investigate the efficacy of nanodiamond irrigation solution with sonic agitation for removing of hard‐tissue debris (HTD) within the isthmus‐containing mesial roots of human mandibular molars using micro‐CT analysis.Forty mesial roots of extracted human mandibular molars were selected based on micro‐computed tomography scans (9‐μm resolution). The mesial canals were mechanically prepared using ProTaper® Gold nickel–titanium rotary instruments and divided into four groups (n = 10 each) according to the final irrigation protocol: sonic agitation with nanodiamond irrigation solution for three 20‐s cycles, sonic agitation with 17% EDTA for three 20‐s cycles, sonic agitation with 3% NaOCl for three 20‐s cycles and manual syringe irrigation with NaOCl using a 30‐G needle syringe for 60 s. The samples were scanned again after canal preparation and the use of the final irrigation protocols. Data were collected to evaluate the percentage of HTD removed. Statistical comparisons were made using the anova post hoc Tukey test (p < .05).None of the irrigation protocols was able to completely eliminate HTD from the isthmus‐containing mesial canals of mandibular molars. However, sonic agitation with the nanodiamond irrigant and sonic agitation with 17% EDTA irrigation solutions showed higher mean reductions of HTD (68.0% and 68.9%, respectively) compared to sonic agitation with 3% NaOCl and manual syringe irrigation with 3% NaOCl (43.4% and 13.7%, respectively) (p < .05).The effectiveness of sonic agitation in removing HTD from the entire root canal was superior to that of manual syringe irrigation. When employing sonic agitation, the addition of nanodiamonds to NaOCl demonstrated enhanced HTD removal capabilities compared to using NaOCl alone and was comparable to that of EDTA. These results suggest that sonic agitation with a nanodiamond irrigation solution may serve as an effective alternative approach for HTD removal in root canal treatment. [ABSTRACT FROM AUTHOR]

In pursuit of diamond nanoparticles, a capacitively-coupled radio frequency flow-through plasma reactor was operated with methane-argon gas mixtures. Signatures of the final product obtained microscopically and spectroscopically indicated that the product was an amorphous form of graphite. This result was consistent irrespective of combinations of the macroscopic reactor settings. To explain the observed synthesis output, measurements of C2 and gas properties were carried out by laser-induced fluorescence and optical emission spectroscopy. Strikingly, the results indicated a strong gas temperature gradient of 100 K per mm from the center of the reactor to the wall. Based on additional plasma imaging, a model of hot constricted region (filamentation region) was then formulated. It illustrated that, while the hot constricted region was present, the bulk of the gas was not hot enough to facilitate diamond sp 3 formation: characterized by much lower reaction rates, when compared to sp 2, sp 3 formation kinetics are expected to become exponentially slow. This result was further confirmed by experiments under identical conditions but with a H2/CH4 mixture, where no output material was detected: if graphitic sp 2 formation was expected as the main output material from the methane feedstock, atomic hydrogen would then be expected to etch it away in situ, such that the net production of that sp 2-hybridized solid material is nearly a zero. Finally, the crucial importance of gas heating was corroborated by replacing RF with microwave source whereby facile sp 3 production was attained with H2/CH4 gas mixture. [ABSTRACT FROM AUTHOR]

Boron nitride has attracted scientific interest in recent years due to its potential use in electronics, both as hexagonal (hBN) and cubic (cBN) phases. While both are successfully realized through chemical vapor deposition, the heteroepitaxial growth of cBN on another iconic semiconductor, diamond is plagued with mixed‐phase formation. Employing first‐principles computations and a nanoreactor approach, the BN phase preferences are explored on diamond (001) controlled—as it is discovered—by the hydrogen gas concentration. In a limited‐hydrogen environment, the initial BN‐island expands along the diamond surface, forming a 3D metastable cubic phase that grows in the direction normal to the basal plane through kinetically‐limited nucleation, thus overcoming the thermodynamic preference toward the hBN phase. Comparatively, the amorphous phase is favored in the absence of hydrogen, while the hexagonal phase dominates at its high levels, elucidating numerous experimental observations. A obtained kinetic phase diagram connects the phase with hydrogen chemical potential to facilitate targeted phase selection. The results suggest that gas‐mediated nucleation kinetics provide feasible control for the precise synthesis. It also offers valuable guidance for the controllable synthesis of desired BN phases and advances research toward potential BN electronics. [ABSTRACT FROM AUTHOR]

The modulation of the electrostatic potential barrier at grain boundaries determines the performance of many ceramic-based electronics such as varistors. However, conventional protocols relying on complex doping and annealing processes inevitably increase the inhomogeneity of microstructure, which may jeopardize the performance stability and mechanical reliability in service. Instead of doping, herein we demonstrate an effective strategy to modulate the potential barrier in ZnO-based low-voltage varistors by exploiting internal stress-induced piezoelectric polarization. The local residual stress as large as ~1 GPa can be created in the ZnO matrix by incorporating ultra-stiff nanodiamond particles using a cold sintering process. As a result, the composite with only 2 wt% of nanodiamond exhibits a prominent nonlinear current-voltage response at a low switch voltage of 15.7 V/mm, which is ascribed to the depressed barrier height induced by the distinct effects of positively and negatively charged polarization on grain boundaries. More strikingly, the large internal stress can significantly enhance the strength of the composite by more than 230% compared with the monolith, owing to the highly strengthened grain boundaries and crack-tip bridging from prestressed nanodiamonds. These findings add internal stress as a new dimension to design mechanically robust ceramic electronics with high performance. The authors find that the large internal stress induced by prestressed stiff nanoparticles can be exploited as an effective tool to modulate the potential barrier while highly enhance the mechanical reliability of ceramics. [ABSTRACT FROM AUTHOR]

Abrikosov vortices play a fundamental role in the magnetic and electric properties of superconductors. The study of their pinning forces is essential to better understand the stability of vortex lattices, with the aim of increasing critical currents in superconductors. However, the study of vortices is challenging because of their nanometric sizes and the large variation in the pinning forces. In this Letter, we use a single nitrogen-vacancy center in a nanodiamond as a nanoscale magneto sensor to locally probe single vortices and their pinning effects in a thin niobium film. This simple, far-field optical approach also offers the possibility of manipulating a single spin with a single flux quantum. [ABSTRACT FROM AUTHOR]

Diamond containing nitrogen‐vacancy centers (NV−) is one of the most investigated materials for quantum technologies, because of this system's exceptional spin properties. Although the NV− optical transition is very bright, it suffers from spectral diffusion and weak zero‐phonon line, and is in the visible range. This limits integration into quantum photonic structures and interfacing with optical fiber networks. In contrast, rare earth (RE) ions exhibit extremely narrow and stable optical transitions, including erbium's 1.5 µm telecom wavelength. Combining RE with NV− properties through short‐range interactions is however challenging as RE do not readily enter the diamond lattice. In this work, a thin‐film‐based architecture in which RE and NV− centers can interact while preserving their unique properties is introduced. Thin films of Er3+:Y2O3 are grown by chemical vapor deposition on diamond substrates with well‐crystallized and highly textured structures. An extensive spectroscopic study of Er3+ transitions at room and low temperatures further reveals that photoluminescence spectra and decays are close to bulk materials. It is also shown that Y2O3 thin film deposition has no detrimental effects on NV− optical and spin properties. RE thin films deposited on diamond can thus be suitable for building hybrid materials for new functionalities in quantum sensing, communication, and processing. [ABSTRACT FROM AUTHOR]

Commercially available powders of detonation nanodiamond (DND) contain extrastrong 20–120 nm sized aggregates, in an amount sometimes up to 50% by mass sustainable to the conventional methods of deaggregation. It demonstrates the significant inhomogeneity structure of products of detonation synthesis and noticeably reduces the yield of 4.0 − 5.0 nm individual isolated particles obtained from DNDs. The presence of these aggregates is obviously related to the some essential features of detonation synthesis. This work presents the results of studying such extrastrong aggregates from DND powder. In order to determine the structure we applied the heat treatment of samples in vacuum and in air, and the subsequent study using Raman spectroscopy, X-ray diffraction, UV–vis spectroscopy, analysis of specific surface and dynamic light scattering (DLS). As a result, a structural model of extrastrong aggregates is proposed. It is shown that extrastrong aggregates consist notably of relatively large (∼8.0 nm) single crystalline diamond particles bonded by facets and covered by smaller 4.5 − 3.0 nm and less crystalline grains. Our results add the details for description of formation processes of diamond particles and aggregates in detonation synthesis from excessive carbon in the composition of explosives. [ABSTRACT FROM AUTHOR]

A first composite material containing uniformly dispersed disaggregated detonation nanocrystalline diamonds (DNDs) in SiO2 aerogel matrix was prepared. The synthetic protocol included hydrolysis of tetramethyl orthosilicate (Si(OMe)4, TMOS) by hydrosol of surface carboxylated DNDs with a typical size of 4–5 nm with DMSO serving as a cosolvent and a stabilizer of DND single crystals. Composite samples containing DNDs in silica aerogel matrix in concentration 1.0, 0.1 and 0.01 % w/w were prepared at ambient temperature. HRTEM data revealed that DNDs nanocrystals were uniformly distributed in aerogel and did not form aggregates. Textural and optical composites' properties were determined. [ABSTRACT FROM AUTHOR]

While lithium resources are scarce for high energy‐dense lithium‐ion batteries (LIBs), sodium‐ion batteries (SIBs), serving as an alternative, inherently suffer from low capacity and the high‐cost use of non‐graphite anodes. Combining Li‐ and Na‐ions within a single battery system is expected to mitigate the shortcomings of both systems while leveraging their respective advantages. In this study, we developed and assembled a nanodiamonds (NDs)‐assisted co‐Li/Na‐ion battery (ND–LSIB). This innovative battery system comprised a commercial graphite anode, an ND‐modified polypropylene (DPP) separator, a hybrid lithium/sodium‐based electrolyte, and a cathode. It is theoretically and experimentally demonstrated that the ND/Li co‐insertion can serve as an ion‐drill opening graphite layers and reconstructing graphite anodes into few‐layered graphene with expanding interlayer space, achieving highly efficient Li/Na storage and the theoretical maximum of LiC6 for Li storage in graphite. In addition, ND is helpful for creating a LiF‐/NaF‐rich hybrid solid electrolyte interface with improved ionic mobility, mechanical strength, and reversibility. Consequently, ND–LSIBs have higher specific capacities ~1.4 times the theoretical value of LIBs and show long‐term cycling stability. This study proposes and realizes the concept of Li/Na co‐storage in one ion battery with compatible high‐performance, cost‐effectiveness, and industrial prospects. [ABSTRACT FROM AUTHOR]

The evolution of the cathodoluminescence spectra from commercially available nanodiamonds with high density of nitrogen‐vacancy defects has been studied in a large wavelength range, from 200 to 800 nm, and temperatures from 5 to 300 K, in order to achieve a temperature probe with high spatial resolution. The full width at half maximum of the peak associated to the neutral charge state of the NV center has been found to evolve with temperature in a predictable way, although its value may vary from sample to sample. We have attributed this shift to the differences in the nanodiamonds surface chemistry. [ABSTRACT FROM AUTHOR]

Free radical generation plays a key role in many biological processes including cell communication, maturation, and aging. In addition, free radical generation is usually elevated in cells under stress as is the case for many different pathological conditions. In liver tissue, cells produce radicals when exposed to toxic substances but also, for instance, in cancer, alcoholic liver disease and liver cirrhosis. However, free radicals are small, short-lived, and occur in low abundance making them challenging to detect and especially to time resolve, leading to a lack of nanoscale information. Recently, our group has demonstrated that diamond-based quantum sensing offers a solution to measure free radical generation in single living cells. The method is based on defects in diamonds, the so-called nitrogen-vacancy centers, which change their optical properties based on their magnetic surrounding. As a result, this technique reveals magnetic resonance signals by optical means offering high sensitivity. However, compared to cells, there are several challenges that we resolved here: Tissues are more fragile, have a higher background fluorescence, have less particle uptake, and do not adhere to microscopy slides. Here, we overcame those challenges and adapted the method to perform measurements in living tissues. More specifically, we used precision-cut liver slices and were able to detect free radical generation during a stress response to ethanol, as well as the reduction in the radical load after adding an antioxidant. [ABSTRACT FROM AUTHOR]

AbstractThermosets, before hardening, consist of independent macromolecules similar to thermoplastics, however, chemical curing of these macromolecules via heat or radiations may form irreversibly crosslinked macromolecular networks between their main chains. Graphene quantum dots are inimitable spherical nano-entities having the advantages of extremely small sizes, of 5-10 nm, very high surface area, surface/edge effects, quantum confinements and a range of physical characteristics including semiconductivity, fluorescence and magnetic properties. Similar to other nanocarbons (like graphene, fullerene or nanodiamonds), graphene quantum dots have been examined as noteworthy nanofillers to enhance the essential physical features of various macromolecular matrices, such as thermosets, thermoplastics and rubbers. Consequently, this review article was intended to systematically discuss the existing scientific state of graphene quantum dots reinforced thermosetting macromolecular matrices for the formation of high performance nanomaterials. According to the literature reports, the type, amount and molecular weight of these macromolecules seemed to affect the epoxy-quantum dots interactions and physical properties, like strength and heat stability of the resulting nanomaterials. Moreover, including graphene quantum dots in thermosetting matrices, like epoxies, hyperbranched polyesters and hyperbranched polyurethanes, has positively influenced the engineering aspects (mainly mechanical and thermal attributes) of the resulting nanocomposites owing to their interactions, compatibility and interfacial tendencies toward these matrices. Principally, epoxy/graphene quantum dots nanocomposites have been fabricated and investigated for the effects of graphene quantum nano-entities on the physical property enhancements of these irreversibly crosslinked macromolecules due to their mutual matrix-nanofiller interfaces. As per our analysis, the literature hitherto on the graphene quantum dots reinforced thermosetting matrix nanocomposites has disclosed significant property improvements of these macromolecules and their promising technological applications for high performance anticorrosion coatings, electromagnetic interference shields and biomedical fields. [ABSTRACT FROM AUTHOR]

Highlights In polymer‐based dental composites, wear is a three‐body wear system mainly abrasive, because of the food particles and wear products suspended in the oral cavity, which are transferred to the microcavities of the surface of the replacements. Due to this fact, the incorporation of nanodiamond as reinforcement in these polymer–matrix composites, which promotes the creation of a solid lubricant tribofilm surface could be advantageous. With the reinforcement of nanodiamonds, BisGMA/TEGDMA‐based composites increase their microhardness by 95%–420%. A maximum hardness exceeding 65 HV is achieved with a reinforcement of 3.2 wt%. The specific wear rate of neat BisGMA/TEGDMA is near 10−4 mm3/Nm and the Archard's coefficient is 2.6 × 105. The incorporation of a content of 1.6 wt% ND is enough to cause a diminution of ~78% in the friction coefficient and a reduction of the specific wear rate and Archard's coefficient of ~50%. Nevertheless, the addition of relatively high contents reduces the effectiveness of photoinitiation and photocuring, which is related to the scattering and absorption of light radiation by ND. This causes a significant decline in elastic properties starting at 50 μm from the surface. Photocuring polymer resin was successfully reinforced with nanodiamonds. Microhardness increases from 95% up to 420%, close to commercial composites. Friction coefficient and wear rate are reduced with 1.6 wt% nanodiamonds. High levels of reinforcement reduce the effectiveness of photocuring. [ABSTRACT FROM AUTHOR]

Highlights In this study, we present a model for predicting the Young's modulus of polymer/nanodiamond (ND) composites, taking into account the interphase properties. The Christensen‐Lo model is adapted and refined to predict the modulus of ND‐based nanocomposites by considering the properties of spherical NDs and their surrounding interphase. The outcomes of the developed model are benchmarked against experimental data, exploring the impact of various parameters, such as ND radius, ND concentration, and interphase properties (thickness and modulus) on the nanocomposite modulus. Findings suggest an inverse correlation between the size of the nanoparticles and the modulus of nanocomposite. Specifically, it is observed that nanoparticles with a minimum radius of 1 nm and a maximum concentration of 5 vol% can increase the nanocomposite modulus by 180%. Additionally, maximum thickness and modulus of the interphase can significantly improve the nanocomposite modulus. The highest interphase thickness of 10 nm and maximum interphase modulus of 100 GPa can grow the modulus of samples by 300%. The predicted influences of all parameters on the nanocomposite modulus validate the accuracy of the developed model. A model for the Young's modulus of polymer nanodiamond (ND) composites is presented. ND radius, ND concentration, and interphase thickness and modulus are considered. The outcomes of the developed model are compared to the experimental data. 5 vol% of the smallest ND (R = 1 nm) increases the nanocomposite modulus by 180%. The thickest and the toughest interphase enhance the nanocomposite modulus by 300%. [ABSTRACT FROM AUTHOR]

The advent of the new 5G communication standard has introduced demanding requirements for the performance of RF front-end filters, necessitating high frequency, large bandwidth, and other improved parameters. Consequently, researchers have been actively investigating the potential of surface acoustic wave resonators and film bulk acoustic resonators to address these needs, leading to the development of numerous novel structures. Through finite element simulation, a new heterogeneous stack structure Al/LN/diamond/Si with an interdigitated electrode resonant cavity is proposed. And the advantageous role of a diamond thin film in the surface acoustic wave resonant structure, including the excitation of high-frequency acoustic resonance modes and modulation of the electromechanical coupling coefficient has been studied. This structure holds promise for addressing the increasing demands for high-frequency, large-bandwidth RF front-end filters in the context of the new 5G communication standard. The results show that the central resonant frequency of the new structure resonator is 5284 MHz, the electromechanical coupling coefficient is 10.96%, and the Q factor value is 10 316, which has potential application value in the field of high-frequency filtering. [ABSTRACT FROM AUTHOR]

Control of the charge state of the nitrogen-vacancy (NV) center is crucial because of its instability and its transitions between the negative (NV–) and neutral (NV0) NV charge states under laser irradiation In this study, we fabricated an n-i-n junction, with an i-layer sandwiched between two phosphorus-doped n-layers; then, we measured the charge state of NV centers under steady state and laser irradiation in a known band structure where the Fermi energy changes gradually. The steady-state charge state measured by a nondestructive single shot exhibited stable NV– and NV0 signals when the Fermi level was even slightly above and below the transition level, respectively. This result indicates that the charge state can be significantly stabilized through band engineering. Both charge-state populations were observed only when the Fermi level was close to the transition level. Under continuous green laser irradiation, the ratio of NV– measured by the photoluminescence spectra changed gradually with the Fermi level in the depletion layer because of the balance between excitation from the laser and the supply of charge from the band. This outcome agrees reasonably with the calculated bands. Furthermore, we measured the PL spectra of the ensemble NV centers and discovered that their charge state can be well-controlled, as in the single NV center. The charge state of the i-layer at the interface can be stabilized by depositing a thin n-layer on the surface. These results would contribute significantly to improve sensor performance. [ABSTRACT FROM AUTHOR]

Absolute kinetics for reactions of C2H2 with a series of ∼60 individual carbon nanoparticles (NPs) from graphite, graphene, graphene oxide, carbon black, diamond, and nano-onion feedstocks were measured for temperatures (TNP) ranging from 1200 to 1700 K. All the NPs were observed to gain mass by carbon addition under conditions that varied with feedstock but with large variations in initial growth rate. Long reaction periods were studied to allow the evolution of growth rates over time to be observed. Diamond NPs were found to passivate against C2H2 addition if heated above ∼1400 K, and the highly variable initial reactivity for carbon nano-onions was found to depend on the presence of non-onion-structure surface carbon. For graphitic and carbon black NPs, three distinct growth modes were observed, correlated with the initial NP mass (Minitial). Smallest graphitic and carbon black NPs, with masses <∼25 MDa, initially grew rapidly but also passivated quickly after adding <4% of Minitial. NPs in the 20–50 MDa range also passivated but only after multiple waves of fast growth separated by periods of low reactivity, with up to ∼11% total mass gain before passivation. The largest carbon black and graphitic NPs, with Minitial >50 MDa, grew rapidly and continuously, adding up to ∼300% of Minitial with no sign of rate slowing as long as C2H2 was present. The efficiencies for C2H2 addition and etching by O2 are strongly correlated, but the correlation changes as the NPs passivate. Growth and passivation mechanisms are discussed. [ABSTRACT FROM AUTHOR]

The Hugoniot elastic limit (HEL) is widely adopted as an important criterion for assessing the dynamic strength of materials, representing the transition stress from elastic to plastic response prior to failure under shock compression. Nano-polycrystalline diamond currently holds the highest HEL of 208 (±14) GPa. Here, we report a diamond-TiC composite (∼11.5 wt. % TiC) showing an ultrahigh HEL of at least 195 (±3.5) GPa, which is comparable to that of nano-polycrystalline diamond. All measured velocity profiles on the diamond-TiC free surface exhibited a single-wave structure at shock pressures of 48–195 GPa. Moreover, the measured Us–Up (shock wave velocity–particle velocity) relation can be linearly fitted, indicating no elastic–plastic transition or solid–solid phase transition up to a shock pressure of 195 GPa. The diamond-TiC composite's compression ratio was similar to that of TiC but significantly higher than that of diamond. These extraordinary dynamic responses are intrinsically attributed to the unique microstructure in which diamond polycrystals are encased in a TiC matrix, providing protection against yielding. Our findings not only developed a mechanically reliable, lightweight, and high-performance armor material at low synthesis costs, but also provided new insights into the shock compression behavior of diamond composites. [ABSTRACT FROM AUTHOR]

Fluorescent nanodiamonds have been used to a large extent in various biological systems due to their robust nature, their inert properties, and the relative ease of modifying their surface for attachment to different functional groups. Within a given batch, however, each nanodiamond is indistinguishable from its neighbors and, so far, one could only rely on fluorescence statistics for some global information about the ensemble. Here, we propose and measure the possibility of adding another layer of unique information, relying on the coupling between the strain in the nanodiamond and the spin degree-of-freedom in the nitrogen-vacancy center in diamond. We show that the large variance in axial and transverse strain can be encoded to an individual radio frequency identity for a cluster of nanodiamonds. When using single nanodiamonds, this unique fingerprint can then be potentially tracked in real-time in, e.g., cells, as their size is compatible with metabolism intake. From a completely different aspect, in clusters of nanodiamonds, this can already serve as a platform for anti-counterfeiting measures. [ABSTRACT FROM AUTHOR]

Hyperthermia plays a significant role in cancer treatment by inducing cell damage through temperature elevation, often used alongside other treatment modalities. During hyperthermia therapy, temperature control is crucial. Here, we report on a simple synthesis route of hybrid plasmonic nanodiamonds either completely wrapped with an Au shell (NV@Au) or densely covered with Au NPs (NV@SiO 2 @Au). Such integration of nanodiamonds with Au NPs is advantageous both for heating and precise thermometry at nanoscale. After structural and optical investigations, heating abilities of the obtained plasmonic nanodiamonds were thoroughly inspected on glass, in association with living cells, and in tissue slices ex vivo, revealing their effective heat generation under excitation with light using a single excitation source. The developed hybrid plasmonic nanodiamonds were finally applied for local photothermal therapy of melanoma in vivo, demonstrating their efficacy in eradicating cancer cells and monitoring temperature during the process.

The interfaces between medical implants and living tissues are of great complexity because of the simultaneous occurrence of a wide variety of phenomena. The engineering of implant surfaces represents a crucial challenge in material science, but the further improvement of implant properties remains a critical task. It can be achieved through several processes. Among them, the production of specialized coatings based on carbon-based materials stands very promising. The use of carbon coatings allows one to simultaneously fine-tune tribological, mechanical, and chemical properties. Here, we review applications of nanostructured carbon coatings (nanodiamonds, carbon nanotubes, and graphene-related materials) for the improvement of the overall properties of medical implants. We are focusing on biological interactions, improved corrosion resistance, and overall mechanical properties, trying to provide a complete overview within the field.

Abstract Since wound healing requires cells to repopulate a damaged area, cell migration is essential. In addition, migration plays a crucial role in cancer metastasis. Whether tumour cells can invade tissue and metastasize is a crucial factor determining their malignancy or in other words a hallmark of cancer (Lazebnik in Nat Rev Cancer 10: 232–233, 2010, https://doi.org/10.1038/nrc2827 ). Nanodiamonds potentially offer a powerful tool to investigate these migration processes. Due to their unprecedented photostability, they can function as long-term fluorescent labels. Besides, nanodiamonds are robust quantum sensors that can reveal, for instance, the temperature or the concentration of certain chemicals with nanoscale resolution. However, to utilise nanodiamonds to study cell migration, it is essential to understand if and how the presence of nanodiamonds influences cell migration. Here, we investigate this process for the first time. We found that nanodiamonds do not alter the speed at which HeLa cells populate a scratch at any tested concentrations. Furthermore, we tested cell attachment by quantifying focal adhesion points. Oxygen-terminated fluorescent nanodiamonds influence the cell spreading, the number of focal adhesions and the size of focal adhesion points. Interestingly, this is different for other types of nanodiamonds in the literature. For these particles, it has been described in the literature that they hinder cell migration. Our results support that fluorescent nanodiamonds do not influence cell migration strongly and thus can be used in labelling and sensing migrating cells. Graphical Abstract

Alina Sigaeva,&ast; Runrun Li,&ast; Jan Jelle van Laar, Leon Wierenga, Romana Schirhagl Department of Biomaterials and Biotechnology, Groningen University, University Medical Center Groningen, Groningen, the Netherlands&ast;These authors contributed equally to this workCorrespondence: Romana Schirhagl, Email romana.schirhagl@gmail.comIntroduction: As nanodiamonds become more and more widely used for intracellular labelling and measurements, the task of delivering these nanoparticles inside cells becomes more and more important. Certain cell types easily take up nanodiamonds, while others require special procedures.Methods: In previous research, we found that HT-29 cells (a colon cancer cell line), which are notoriously difficult in the context of nanodiamond internalization, show increased uptake rates, when pre-treated with trypsin- ethylenediaminetetraacetic acid (trypsin-EDTA). However, the uptake mechanism has not been studied before. This article focuses on a more detailed investigation of the reasons underlying this phenomenon. We start by identifying the timing of fluorescent nanodiamond (FND) uptake in trypsin-EDTA pre-treated cells. We then use a combination of chemical inhibitors and Immunocytochemistry to identify the main pathways employed by HT-29 cells in the internalization process.Results and Discussion: We investigate how these pathways are affected by the trypsin-EDTA pre-treatment and conclude by offering possible explanations for this phenomenon. We found that nanodiamonds are internalized via different pathways. Clathrin-mediated endocytosis proves to be the dominating mechanism. Trypsin-EDTA treatment increases particle uptake and affects the uptake mechanism.Keywords: nanodiamonds, cell uptake, cancer cells, HT29 cells, NV centers, imaging

We report the successful assembly of a tripeptide in the presence of nanodiamonds (NDs) into nanocomposite hydrogels. While the presence of NDs does not hinder peptide self‐assembly and gelation kinetics are not affected, NDs improve the viscoelastic properties and significantly increase the elastic moduli of the peptide hydrogels. Increased resistance of the gels against applied stress can also be attained depending on the amount of NDs loaded in the nanocomposite. Raman micro‐spectroscopy and TEM confirmed the presence of NDs on the surface, and not in the interior, of peptide nanofibers. Peptide‐ND non‐covalent interactions are also probed by Raman and Fourier‐transformed infrared spectroscopies. Overall, this work enables the embedding of NDs into nanocomposite hydrogels formed through the self‐assembly of a simple tripeptide at physiological pH, and it provides key insights to open the way for their future applications in biomaterials, for instance exploiting their luminescence and near‐infrared responsiveness. [ABSTRACT FROM AUTHOR]

Sensing based on Nitrogen‐Vacancy (NV) centers in nanodiamonds (NDs) represents a potentially groundbreaking technology with broad applications. Nevertheless, the optimization of their quantum‐optical properties is still a challenging issue. The present work aims at enhancing and controlling NV centers optical properties in NDs by combining their surface chemistry tuning and proton beam irradiation. Systematic thermal oxidations are carried out to study the evolution of surface chemical groups (IR spectroscopy), as well as their influence on optical properties (photoluminescence spectroscopy, PL decay measurements). Proton irradiation is performed by exploring a wide range of fluences (1014 – 1017 cm−2) in order to precisely control the amount of NV centers, thus defining the conditions that maximize their creation and emission intensity. In addition, NV centers charge state control is achieved by assessing NV−/NV0 ratio upon different surface termination tuning and NV centers amount. Finally, a novel predictive mathematical model is developed, allowing for the evaluation of the efficiencies of the formation of both NV− and NV0. Although the model is tested in the specific case study with proton irradiated NDs, it offers a broad applicability, thus representing a key landmark in the prediction of the outcome of ion‐beam‐based color centers generation in diamond. [ABSTRACT FROM AUTHOR]

The surfaces of nanodiamond particles are modified using natural castor oil‐derived 12‐hydroxystearic acid, which has thixotropic solvent properties. 12‐Hydroxystearyl chain‐modified nanodiamonds (12OHSt‐ND) are spread from a dispersion medium onto ultrapure water to afford Langmuir monolayers (a single‐particle layer) of 12OHSt‐ND exhibited a two‐dimensional phase transition from an expanded phase to a condensed phase. The surface morphology of the single‐particle layer shows a dispersed form of aggregated particles, while the layered regularity of the multilayers shows high periodicity. The surface hydrophobicity of the single‐particle layer of 12OHSt‐ND is more pronounced than that of the single‐particle layer of stearic acid‐modified nanodiamonds. The origin of the surface hydrophobicity of the single‐particle layer of 12OHSt‐ND is predicted to be the vertical conformation of the modified chains achieved via hydrogen bonding between the modified chains. In addition, the stepwise multilayers of 12OHSt‐ND exhibit various structural colors depending on the number of layers. [ABSTRACT FROM AUTHOR]

AbstractNanodiamonds are unique spherical carbon nano-entities having the advantages of very high surface area and high optical, thermal, wear and strength characteristics. Like other carbonaceous nanoparticles (like fullerene, graphene or carbon nanotube), nanodiamond nano-reinforcements have been investigated for the significant types of polymeric matrices (such as thermosets, thermoplastics, rubbers) nanocomposites. Consequently, this overview was planned to systematically describe the current scientific status of the nanodiamonds reinforced thermoplastic nanomaterials. In this regard, polyamide/nanodiamonds, polyimide/nanodiamonds and polystyrene/nanodiamonds nanocomposites have been fabricated using the facile solution, in-situ and melt mixing techniques. We suggest that including nanodiamonds in polyamides and polyimides increased their engineering characteristics, like mechanical properties and thermal stability, of the resulting nanocomposites due to a distinct interface formation and their compatibilization effects toward these matrices. Correspondingly, including nanodiamonds in polystyrene has been observed to increase the intrinsically low strength/toughness features of this polymer. Predominantly, nano-reinforcement and miscibility effects of the nanodiamonds with the polystyrene and their mutual matrix-nanofiller synergies were responsible to improve the overall microstructural and physical properties of the resulting nanocomposites. As per our analysis, the research reports so far on the important categories of the nanodiamonds reinforced thermoplastic matrix nanocomposites have shown important technical applications in the fields of high-tech coatings, membranes and energy devices. [ABSTRACT FROM AUTHOR]

Nanodiamonds (NDs) are utilized for various purposes in dentistry, such as tissue regeneration, gene therapy, and medication delivery. Despite the examination of their potential for dental uses, there is currently no published review summarizing the conducted investigations. Additional investigations are required to comprehend the biological compatibility of NDs in dentistry. NDs have been proven effective for a variety of applications in dentistry because of unique qualities such as target cell selectivity, nanometer size, and fluorescence. Nanodiamonds find various applications in dentistry, encompassing roles in directed tissue regeneration, reinforcing polymers, and administering medications for treating infections and cancer. Researchers have also suggested the potential use of nanodiamonds as coatings for antibacterial or bioactive dental implants. Nevertheless, investigations on their biological compatibility have been scarce and insufficient so far, necessitating significantly further studies to envision the potential use of NDs in dentistry. It is believed that within the ten years to come, these emerging substances will discover several kinds of daily usage in dental practice. [ABSTRACT FROM AUTHOR]

Fluorescent nanodiamonds (FNDs) are carbon-based nanomaterials that emit bright, photostable fluorescence and exhibit a modifiable surface chemistry. Myeloid-derived suppressor cells (MDSCs) are an immunosuppressive cell population known to expand in cancer patients and contribute to worse patient outcomes. To target MDSC, glycidol-coated FND were conjugated with antibodies against the murine MDSC markers, CD11b and GR1 (dual-Ab FND). In vitro, dual-Ab FND uptake by murine MDSC was significantly higher than IgG-coated FND (94.7% vs. 69.0%, p < 0.05). In vivo, intra-tumorally injected dual-Ab FND primarily localized to the tumor 2 and 24 h post-injection, as measured by in vivo fluorescence imaging and flow cytometry analysis of the spleen and tumor. Dual-Ab FND were preferentially taken up by intra-tumoral MDSC, representing 87.1% and 83.0% of FND+ cells in the tumor 2 and 24 h post-injection, respectively. Treatment of mice with anti-PD-L1 immunotherapy prior to intra-tumoral injection of dual-Ab FND did not significantly alter the uptake of FND by MDSC. These results demonstrate the ability of our novel dual-antibody conjugated FND to target MDSC and reveal a potential strategy for targeted delivery to other specific immune cell populations in future cancer research. [ABSTRACT FROM AUTHOR]

AbstractNanodiamonds have been researched as sphere-shaped carbon nano-entities having countless surface/structural properties, facile fabrication and mammoth technological value. An important utilization of nanodiamonds has been observed as nano-reinforcing agents for nanocompositing purposes. Semiconducting polymers (conjugated polymers) having π electron delocalization have been documented for worthy electrochemical/optical/thermal/mechanical features, in addition to the electron transfer through their backbone. Doping of carbonaceous nanoparticles, like nanodiamonds, with conjugated polymers have been found to further improve the valuable physical characteristics in their final nanocomposite form. Correspondingly, this overview describes the impact of nanodiamond nano-reinforcement on the specialized aspects of polyaniline/nanodiamond, polypyrrole/nanodiamond and polythiophene/nanodiamond nanocomposites. According to literature reports, these groupings of conjugated polymer/nanodiamond hybrids revealed noteworthy microstructural, conductive, optical, electrochemical, microwave absorption, specific capacitance, photovoltaic and actuation characteristics. Subsequently, several significant applications of polymer/nanodiamond nanomaterials have been explored including the solar cells, supercapacitors and actuators. [ABSTRACT FROM AUTHOR]

The objective of this research is to investigate the potential impact of nanodiamond filler particles on the mechanical and morphological characteristics of epoxy composites that are fortified with ramie and jute fibers. Composed of composite laminates containing nanodiamonds at concentrations of 0.1, 0.3, and 0.5 wt. %, the laminates were produced via vacuum‐assisted resin infusion (VARI to evaluate the alterations in mechanical properties, Vickers hardness, tensile, and flexural tests were conducted on the prepared composites). The findings showed that adding 0.3 wt. % nanodiamonds to epoxy composites significantly improved the hardness of the composites about 18.56% and 34.38%, the tensile strength of the composites about 19.1% and 28.01%, and the flexural strength of the composites about 17.7% and 21.12% for ramie/epoxy and jute/epoxy, respectively. The optimal concentration of nanodiamonds for both types of fibers in order to optimize these properties was calculated to be 0.3 wt. % of nanodiamonds. A micro‐x‐ray CT scan was performed to determine the percentage of porosity in composites. The utilization of scanning electron microscopy (SEM) demonstrated that an increase in the nanodiamond content led to enhanced fiber dispersion and reduced interfacial voids. In contrast, Fourier transform infrared (FTIR) analysis unveils the hydrophobic characteristics, cellulose content, and improved interfacial bonding between the fibers and the epoxy matrix, which is attributed to the robust covalent bonding enabled by the nanodiamonds. Highlights: Adding nanodiamonds (NDs) improved adhesion at fiber‐matrix interface.Mechanical properties peaked for composites with 0.3 wt. % of NDs.Beyond 0.3 wt. % of NDs, agglomerates in composites were observed through SEM.Void percent increased for composites with 0.5 wt. % of NDs. [ABSTRACT FROM AUTHOR]

The properties of graphene oxide–detonation nanodiamond composites obtained as a result of heterocoagulation of graphene oxide and hydrogenated detonation nanodiamonds in aqueous mixtures were studied. The resulting composites with different proportions of graphene oxide and detonation nanodiamond were subjected to drying and subsequent heat treatment in a vacuum, converting graphene oxide into graphene. The structure of the composites was studied using electron microscopy and Raman spectroscopy. The specific surface area and porosity of the obtained samples were studied by analyzing nitrogen adsorption isotherms. A model for the composite formation and a possible technology for producing a material based on it with different specific surface area values and pore structure are proposed. It is shown, that the largest possible specific surface area of two-component structures of the «DND/GO» type does not exceed 500 m2·g−1. It was also concluded that it is necessary to achieve a uniform distribution of detonation nanodiamond particles over the surface of graphene sheets. [ABSTRACT FROM AUTHOR]

Optically addressable spin defects in three-dimensional (3D) crystals and two-dimensional (2D) van der Waals (vdW) materials are revolutionizing nanoscale quantum sensing. Spin defects in one-dimensional (1D) vdW nanotubes will provide unique opportunities due to their small sizes in two dimensions and absence of dangling bonds on side walls. However, optically detected magnetic resonance of localized spin defects in a nanotube has not been observed. Here, we report the observation of single spin color centers in boron nitride nanotubes (BNNTs) at room temperature. Our findings suggest that these BNNT spin defects possess a spin S = 1/2 ground state without an intrinsic quantization axis, leading to orientation-independent magnetic field sensing. We harness this unique feature to observe anisotropic magnetization of a 2D magnet in magnetic fields along orthogonal directions, a challenge for conventional spin S = 1 defects such as diamond nitrogen-vacancy centers. Additionally, we develop a method to deterministically transfer a BNNT onto a cantilever and use it to demonstrate scanning probe magnetometry. Further refinement of our approach will enable atomic scale quantum sensing of magnetic fields in any direction. Optically addressable spin defects, such as the NV centre in diamond, have enabled the nanoscale measurement of external stimuli. Here, Gao, Vaidya and coauthors observe a single spin colour centres in boron nitride nanotubes, which, due to their spin S = 1/2 ground state, allow for omnidirectional magnetic field sensing. ' [ABSTRACT FROM AUTHOR]

We use a simple and effective experimental method for determining the radiative quantum yield of single silicon-vacancy centers (SiV) in nanometric-sized diamonds (NDs). It is based on variations in the luminescence lifetimes of SiVs induced by a controlled change in the NDs' dielectric environment. The deposition of a high refractive index immersion oil on a thin polymer sample containing NDs with an average size of 20 nm induces a noticeable shortening of SiV lifetimes, a clear signature of a strong radiative contribution to the decays. While SiV centers were generally considered to be weak quantum emitters, we demonstrate that single SiV centers in nanodiamonds have a quantum efficiency up to 60 % , under ambient conditions. This quantum efficiency is very similar to that of the negatively charged nitrogen-vacancy centers, which we measured using the same approach. This feature makes single SiV attractive as bright, high-purity single-photon sources for quantum technologies. [ABSTRACT FROM AUTHOR]

Nanodiamonds (NDs) offer immense potential in various fields, but graphitic or metal-based impurities hinder their widespread adoption. Conventional purification methods often employ harsh chemicals or high temperatures, raising concerns about ND integrity and surface properties. Herein, we compared various strategies to purify and tailor the surface functional groups in the detonation-derived NDs. A facile 2-step purification strategy combining salt-assisted air oxidation (SAAO) and Fenton chemistry is particularly interesting for efficient and selective removal of graphitic impurities while preserving the diamond lattice structure. SAAO selectively burns off graphitic impurities at 450 °C under controlled oxygen flow, minimizing damage to the diamond core. Subsequently, Fenton's reagent (H2O2/Fe2+) introduces hydrophilic functional groups onto the ND surface, further enhancing diamond purity and promoting subsequent functionalization. This synergistic approach enables (i) highly efficient removal of graphitic impurities while preserving ND morphology and crystal structure, (ii) controlled introduction of surface functionalities, and (iii) improved colloidal stability of purified NDs. This green and efficient purification protocol is beneficial for tailoring ND properties and unlocking their full potential in diverse applications ranging from biomedicine and electronics to catalysis and quantum technologies. [ABSTRACT FROM AUTHOR]

Background: Glioblastoma multiforme (GBM) is recognized as the most lethal and most highly invasive tumor. The high likelihood of treatment failure arises fromthe presence of the blood-brain barrier (BBB) and stemcells around GBM, which avert the entry of chemotherapeutic drugs into the tumormass. Objective: Recently, several researchers have designed novel nanocarrier systems like liposomes, dendrimers, metallic nanoparticles, nanodiamonds, and nanorobot approaches, allowing drugs to infiltrate the BBB more efficiently, opening up innovative avenues to prevail over therapy problems and radiation therapy. Methods: Relevant literature for this manuscript has been collected from a comprehensive and systematic search of databases, for example, PubMed, Science Direct, Google Scholar, and others, using specific keyword combinations, including "glioblastoma," "brain tumor," "nanocarriers," and several others. Conclusion: This review also provides deep insights into recent advancements in nanocarrier-based formulations and technologies for GBM management. Elucidation of various scientific advances in conjunction with encouraging findings concerning the future perspectives and challenges of nanocarriers for effective brain tumor management has also been discussed. [ABSTRACT FROM AUTHOR]

Nanothermometry is crucial for understanding physical, chemical, and biological systems, which require precise temperature measurement. Fluorescent nanodiamonds containing nitrogen-vacancy (NV) color centers offer an approach to temperature sensing. In this study, we present the spectrofluorometric characteristics of the NV zero-phonon lines (575 and 637 nm), in 100 nm nanodiamonds in aqueous volume ensembles at a concentration of 0.5 mg/ml, across the temperature range of 30–45 °C. The NV0 and NV− fluorescence intensities achieved high linear correlation values of 0.99 (INV0) and 0.94 (INV−), respectively, demonstrating their efficiency in high precision temperature assessment. Additionally, we explore NV0 width as temperature increases, NV populations intensity ratios, and INV0/INV− ratios to gain insights into thermal quenching phenomena in fluorescent nanodiamonds, where upon heating, an increasing trend for INV−/(INV0+INV−) is observed, while an antisymmetric effect takes place for INV0/(INV0+INV−). These findings indicate the potential of commercial nanodiamonds for precise all-optical fluorescence-based temperature sensing. [ABSTRACT FROM AUTHOR]

Since wound healing requires cells to repopulate a damaged area, cell migration is essential. In addition, migration plays a crucial role in cancer metastasis. Whether tumour cells can invade tissue and metastasize is a crucial factor determining their malignancy or in other words a hallmark of cancer (Lazebnik in Nat Rev Cancer 10: 232–233, 2010, https://doi.org/10.1038/nrc2827). Nanodiamonds potentially offer a powerful tool to investigate these migration processes. Due to their unprecedented photostability, they can function as long-term fluorescent labels. Besides, nanodiamonds are robust quantum sensors that can reveal, for instance, the temperature or the concentration of certain chemicals with nanoscale resolution. However, to utilise nanodiamonds to study cell migration, it is essential to understand if and how the presence of nanodiamonds influences cell migration. Here, we investigate this process for the first time. We found that nanodiamonds do not alter the speed at which HeLa cells populate a scratch at any tested concentrations. Furthermore, we tested cell attachment by quantifying focal adhesion points. Oxygen-terminated fluorescent nanodiamonds influence the cell spreading, the number of focal adhesions and the size of focal adhesion points. Interestingly, this is different for other types of nanodiamonds in the literature. For these particles, it has been described in the literature that they hinder cell migration. Our results support that fluorescent nanodiamonds do not influence cell migration strongly and thus can be used in labelling and sensing migrating cells. [ABSTRACT FROM AUTHOR]

The emerging field of optical magnetometry utilizing negative-charged nitrogen vacancy (NV−) centers provides a highly sensitive lab bench technique for spatially resolved physical property measurements. Their implementation in high pressure diamond anvil cell (DAC) environments will become common as other techniques are often limited due to the spatial constraints of the sample chamber. Apparatus and techniques are described here permitting for more general use of magnetic field measurements inside a DAC using continuous wave optical detected magnetic resonance in NV− centers in a layer of nanodiamonds. A microstrip antenna delivers a uniform microwave field to the DAC and is compatible with simple metal gaskets, and the sensor layer of deposited nanodiamonds allows for simple determination of the magnetic field magnitude for B in the 1–100 G range. The ferromagnetic transition in iron at 18 GPa is measured with the apparatus, along with its hysteretic response. [ABSTRACT FROM AUTHOR]

Herein, a disposable electrochemical sensor was constructed from a gold DVD (GDVD) mini-chip modified with pores, β-cyclodextrin capped gold nanoparticles (AuNPs@β-CD), and nanodiamond (ND). For this purpose, the LSV method was employed to deposit a silver film on the surface of the mini-chip. Then, the silver was replaced with gold using galvanic replacement, after which etching of silver by nitric acid and ammonia was accomplished to obtain a porous GDVD mini-chip (PGDVD). Next, AuNPs@β-CD and thereafter, an aqueous ND dispersion were successively drop-cast on the PGDVD. Finally, the as-prepared mini-chip was exposed to air to obtain the PGDVD@AuNps@β-CD@ND mini-chip. The electrochemical oxidation behaviour of BPA showed an irreversible oxidative wave with decreased oxidation overpotential and increased current response for BPA. The calibration curve was linear over the concentration range of 5 × 10−5 M to 1 × 10−3 M of BPA. According to the 3sb/m and 10sb/m criteria, the limits of detection (LOD) and quantitation (LOQ) of the method were obtained to be 1 × 10−5 M and 5 × 10−5 M, respectively. Also, the reproducibility of the method (RSD%) was obtained to be 4%. The proposed sensor was employed for the analysis of spiked tap water and apple juice samples. [ABSTRACT FROM AUTHOR]

Optically active color centers in diamond and nanodiamonds can be utilized as quantum sensors for measuring various physical parameters, particularly magnetic and electric fields, as well as temperature. Due to their small size and possible surface functionalization, fluorescent nanodiamonds are extremely attractive systems for biological and medical applications since they can be used for intracellular experiments. This review focuses on fluorescent nanodiamonds for thermometry with high sensitivity and a nanoscale spatial resolution for the investigation of living systems. The current state of the art, possible further development, and potential limitations of fluorescent nanodiamonds as thermometers will be discussed here. [ABSTRACT FROM AUTHOR]

Diamond as a templating substrate is largely unexplored, and the unique properties of diamond, including its large bandgap, thermal conductance, and lack of cytotoxicity, makes it versatile in emergent technologies in medicine and quantum sensing. Surface termination of an inert diamond substrate and its chemical reactivity are key in generating new bonds for nucleation and growth of an overlayer material. Oxidized high-pressure high temperature (HPHT) nanodiamonds (NDs) are largely terminated by alcohols that act as nucleophiles to initiate covalent bond formation when an electrophilic reactant is available. In this work, we demonstrate a templated synthesis of ultrathin boron on ND surfaces using trigonal boron compounds. Boron trichloride (BCl3), boron tribromide (BBr3), and borane (BH3) were found to react with ND substrates at room temperature in inert conditions. BBr3 and BCl3 were highly reactive with the diamond surface, and sheet-like structures were produced and verified with electron microscopy. Surface-sensitive spectroscopies were used to probe the molecular and atomic structure of the ND constructs' surface, and quantification showed the boron shell was less than 1 nm thick after 1–24 h reactions. Observation of the reaction supports a self-terminating mechanism, similar to atomic layer deposition growth, and is likely due to the quenching of alcohols on the diamond surface. X-ray absorption spectroscopy revealed that boron-termination generated midgap electronic states that were originally predicted by density functional theory (DFT) several years ago. DFT also predicted a negative electron surface, which has yet to be confirmed experimentally here. The boron-diamond nanostructures were found to aggregate in dichloromethane and were dispersed in various solvents and characterized with dynamic light scattering for future cell imaging or cancer therapy applications using boron neutron capture therapy (BNCT). The unique templating mechanism based on nucleophilic alcohols and electrophilic trigonal precursors allows for covalent bond formation and will be of interest to researchers using diamond for quantum sensing, additive manufacturing, BNCT, and potentially as an electron emitter. [ABSTRACT FROM AUTHOR]

In this paper, the nano-diamond decorated reduced graphene oxide (Diamond-RGO) and its polyimide (PI) composite, by using in situ polymerization method, are synthesized, respectively. The tribological study of Diamond-RGO/PI composite exhibits super anti-wear properties under dry sliding and high load condition: the lowest wear rate of 4.9 × 10−8mm3N−1m−1, which is extraordinarily lower than that of pure PI and RGO/PI composite, is obtained under load 100 N. The tribological mechanism investigation shows that Diamond-RGO composite has a strong synergistic effect in the tribological process which contributes to form a uniform transfer film on the counterpart ring and thus significantly decrease the composite's wear rate. Through molecular simulation, the shear behavior of the composite material indicates that the presence of the Diamond-RGO composite will obviously weaken the influence of the iron wall on the PI bulk phase molecular chain in the shear process. This confirms that the synergistic effect between nano-Diamond and RGO will improve its PI composite's tribological performance on atomic level. [ABSTRACT FROM AUTHOR]

Diamond nanoparticles represent an elegant class of nanoscale materials with promising applications in nanotechnology. Solid-state NMR is a powerful technique for investigating the atomic-level structure and dynamics of nanomaterials in their natural state. The present study illustrates the application of high-resolution 13C NMR to nanomaterials characterization, and the fundamental 13C spin–lattice relaxation times highlight the spatial arrangement of surface-associated paramagnetic centers around the core sp3 carbon assembly of diamond nanoparticles, delineating the unique size-dependent physicochemical characteristics of diamond nanoparticles. [ABSTRACT FROM AUTHOR]

Cobalt-based catalysts exhibit excellent reactivity and carbon chain growth capability in the Fischer-Tropsch synthesis reaction, and their catalytic performance is closely related to the reduction degree and size of metal Co particles. Regulating the reduction degree and dispersion degree of metal Co by adding promoters is an important way to enhance their catalytic performance in Fischer-Tropsch synthesis reaction. By using SiC as a support with chemical inertness and good thermal conductivity, and adding a small amount of nanodiamonds (NDs) with rich surface functional groups as structural regulators, the dispersion degree and reduction degree of Co species in the catalyst were effectively improved, and its catalytic performance in Fischer-Tropsch synthesis reaction was enhanced. The results of N2 physical adsorption/desorption show that the addition of NDs has little effect on the parameters such as specific surface areas and pore sizes of the catalysts. The results of CO chemisorption show that the addition of an appropriate amount of NDs promotes the dispersion of active metal Co in the catalysts, increases the surface area of metal Co and provides more active sites for the Fischer-Tropsch synthesis reaction. The results of transmission electron microscopy (TEM) show that after the addition of NDs to Co/SiC (m(NDs):m(SiC) = 1.0%), the particle sizes of metal Co in the catalysts are reduced, and NDs are uniformly dispersed on the catalyst surface. The results of H2-temperature programmed reduction (H2-TPR) and CO-H2-temperature programmed surface reaction (CO-H2-TPSR) show that the addition of NDs reduces the reduction temperature of Co3O4 to metal Co and promotes the reduction of Co3O4 and the activation of CO. Compared with the Co/SiC catalyst, the NDs-modified Co/1.0NDs-SiC (W(Co) = 10%, OT(NDS):M(SiC) = 1.0%) catalyst exhibits an increase of CO conversion rate from 15.6% to 29.0%, and the selectivity of C5+ hydrocarbon products still maintains at above 75%, and shows stable operation and no significant deactivation for 70 h. The above results can provide a new research idea for the development of efficient catalysts modified with nanocarbon materials in Fischer-Tropsch synthesis reaction. [ABSTRACT FROM AUTHOR]