Boron-doped diamond nanosheet volume-enriched screen-printed carbon electrodes: a platform for electroanalytical and impedimetric biosensor applications.

This paper focuses on the development of a novel electrode based on boron-doped diamond nanosheet full-volume-enriched screen-printed carbon electrodes (BDDPE) for use as an impedimetric biosensor. Impedimetric biosensors offer high sensitivity and selectivity for virus detection, but their use as point-of-care devices is limited by the complexity of nanomaterials' architecture and the receptor immobilisation procedures. The study presents a two-step modification process involving the electroreduction of diazonium salt at the BDDPE and the immobilisation of antibodies using zero-length cross-linkers for a selective impedimetric biosensor of Haemophilus influenzae (Hi). The incorporation of diamond nanosheets into BDDPE leads to enhanced charge transfer and electrochemical behaviour, demonstrating greatly improved electrochemically active surface area compared with unmodified screen-printed electrodes (by 44% and 10% on average for [Ru(NH3)6]Cl2 and K3[Fe(CN)6], respectively). The presented sensing system shows high specificity towards protein D in Hi bacteria, as confirmed by negative controls against potential interference from other pathogens, with an estimated tolerance limit for interference under 12%. The Hi limit of detection by electrochemical impedance spectroscopy was 1 CFU/mL (measured at - 0.13 V vs BDDPE pseudo-reference), which was achieved in under 10 min, including 5 min sample incubation in the presence of the analyte.

Prospects of single-cell nuclear magnetic resonance spectroscopy with quantum sensors.

Single-cell analysis can unravel functional heterogeneity within cell populations otherwise obscured by ensemble measurements. However, noninvasive techniques that probe chemical entities and their dynamics are still lacking. This challenge could be overcome by novel sensors based on nitrogen-vacancy (NV) centers in diamond, which enable nuclear magnetic resonance (NMR) spectroscopy on unprecedented sample volumes. In this perspective, we briefly introduce NV-based quantum sensing and review the progress made in microscale NV-NMR spectroscopy. Last, we discuss approaches to enhance the sensitivity of NV ensemble magnetometers to detect biologically relevant concentrations and provide a roadmap toward their application in single-cell analysis.

Degradation of levofloxacin from antibiotic wastewater by pulse electrochemical oxidation with BDD electrode.

Antibiotic-containing wastewater is a typical biochemical refractory organic wastewater and general treatment methods cannot effectively and quickly degrade the antibiotic molecules. In this study, a novel boron-doped diamond (BDD) pulse electrochemical oxidation (PEO) technology was proposed for the efficient removal of levofloxacin (LFXN) from wastewater. The effects of current density (j), initial pH (pH0), frequency (f), electrolyte types and initial concentration (c0(LFXN)) on the degradation of LFXN were systematically investigated. The degradation kinetics under four different processes have also been studied. The possible degradation mechanism of LFXN was proposed by Density functional theory calculation and analysis of degradation intermediates. The results showed that under the optimal parameters, the COD removal efficiency (η(COD)) was 94.4% and the energy consumption (EEC) was 81.43 kWh·m-3 at t = 120 min. The degradation of LFXN at pH = 2.8/c(H2O2) followed pseudo-first-order kinetics. The apparent rate constant was 1.33 × 10-2 min-1, which was much higher than other processes. The degradation rate of LFXN was as follows: pH = 2.8/c(H2O2) > pH = 2.8 > pH = 7/c(H2O2) > pH = 7. Ten aromatic intermediates were formed during the degradation of LFXN, which were further degraded to F-, NH4+, NO3-, CO2 and H2O. This study provides a promising approach for efficiently treating LFXN antibiotic wastewater by pulsed electrochemical oxidation with a BDD electrode without adding H2O2.

Utility of "flip-flop" chromatography employing silica hydride stationary phases with simultaneous photodiode array ultraviolet and single quadrupole mass detection for the analysis of seized drugs.

For confirmation and/or screening purposes, rapid, selective, and precise chromatographic methods are required. In this vein, the utility of SiH columns (C18, UDC Cholesterol, and Diamond Hydride) with photodiode array UV absorption and single quadrupole MS detection for multi-modal separation of representative drugs from different drug classes on a single column using the same solvent reservoirs was investigated. For a conventional two column approach employing a combination of conventional C18 and silica columns operating in both the reversed phase chromatographic and hydrophilic interaction chromatographic modes, gradient analysis is required for the first column and there is a lack of retention on the second column for non-amine analytes. In comparison, all analytes are retained for two relatively rapid (< 10 min), precise (% RSD <0.4%), and non-correlated isocratic separations (R2=0.2115) when using a UDC Cholesterol column.

Influence of different surface treatment on bonding of metal and ceramic Orthodontic Brackets to CAD-CAM all ceramic materials.

BACKGROUND: Developing efficient bonding techniques for orthodontic brackets and all-ceramic materials continues to pose a clinical difficulty. This study aimed to evaluate the shear bond strengths (SBS) of metal and ceramic brackets to various all-ceramic CAD-CAM materials, such as lithium disilicate CAD (LDS-CAD), polymer-infiltrated ceramic (PIC), zirconia-reinforced lithium silicate glass ceramic (ZLS), and 5YTZP zirconia after different surface treatments and thermal cycling. MATERIALS AND METHODS: The samples were divided into two groups to be bonded with ceramic and metal lower incisor brackets. Each group was subdivided into a control group devoid of any surface treatment, 10% HF acid (HFA) etching, ceramic etch & prime (MEP), Al2O3 air abrasion, and medium grit diamond bur roughening. After surface treatment, brackets were bonded with composite resin cement, thermal cycled, and tested for shear bond strength. The failed surfaces were evaluated with a digital microscope to analyse the type of failure. The data were statistically analysed using a one-way ANOVA and Tukey HSD tests at p < 0.05. RESULTS: The highest mean bond strengths were found with HFA etching in LDS-CAD (13.17 ± 0.26 MPa) and ZLS (12.85 0.52 MPa). Diamond bur recorded the lowest mean bond strength roughening across all the ceramic groups. There were significant differences in mean shear bond values per surface treatment (p < 0.001) and ceramic materials. CONCLUSION: Among the surface treatment protocols evaluated, HFA etching and MEP surface treatment resulted in enhanced bond strength of both ceramic and metal brackets to CAD-CAM all ceramic materials.

Residual stress associated with crystalline phase transformation of 3-6 mol% yttria-stabilized zirconia ceramics induced by mechanical surface treatments.

Monolithic dental prostheses made of 3-6 mol% yttria-stabilized zirconia (3-6YSZ) have gained popularity owing to their improved material properties and semi-automated fabrication processes. In this study, we aimed to evaluate the influence of mechanical surface treatments, such as polishing, grinding, and sandblasting, on the residual stress of 3-6YSZ used for monolithic prostheses in association with crystalline phase transformation. Plate specimens were prepared from five dental zirconia blocks: Aadva Zirconia ST (3YSZ), Aadva Zirconia NT (6YSZ), Katana HT (4YSZ), Katana STML (5YSZ), and Katana UTML (6YSZ). The specimens were either polished using 1, 3, or 9 µm diamond suspensions, ground using 15, 35, or 55 µm diamond discs, or sandblasted at 0.2, 0.3, or 0.4 MPa. The residual stress, crystalline phase, and hardness were analyzed using the cosα method, X-ray diffraction (XRD), and Vickers hardness test, respectively. Additionally, we analyzed the residual stress on the surfaces of monolithic zirconia crowns (MZCs) made of 4YSZ, 5YSZ, and 6YSZ, which were processed using clinically relevant procedures, including manual grinding, followed by polishing using a dental electric motor on the external surface, and sandblasting on the internal surface. Residual stress analysis demonstrated that grinding and sandblasting, particularly the latter, resulted in the generation of compressive residual stress on the surfaces of the plate specimens. XRD revealed that the ground and sandblasted specimens contained a larger amount of the rhombohedral phase than that of the polished specimens, which may be a cause of the residual stress. Sandblasting significantly increased the Vickers hardness compared to polishing, which may possibly be due to the generation of compressive residual stress. In the case of MZCs, compressive residual stress was detected not only on the sandblasted surface, but also on the polished surface. The difference in the residual stress between the plate and crown specimens may be related to the force applied during the automated and manual grinding and polishing procedures. Further studies are required to elucidate the effects of the compressive residual stress on the clinical performance of MZCs.

Antibody-Conjugated Nanodiamonds as Dual-Functional Immunosensors for In Vitro Diagnostics.

Nanodiamonds (NDs) are carbon nanoparticles with a large refractive index, a high density, and exceptional chemical stability. When excited by green light, they can emit bright red fluorescence from implanted nitrogen-vacancy (NV) centers. Taking advantage of these properties, we have developed antibody-conjugated NDs as in vitro diagnostic sensors for two complementary assays: particle-enhanced turbidimetric immunoassay (PETIA) and spin-enhanced lateral flow immunoassay (SELFIA). To achieve this goal, monocrystalline diamond powders (∼100 nm in diameter) with or without NV implantation were first treated in molten KNO3 to reduce their size and shape inhomogeneity, followed by surface carboxylation in strong oxidative acids and non-covalent conjugation with antibodies in water. PETIA and SELFIA were carried out separately with a microplate reader and a magnetically modulated fluorescence analyzer. Using C-reactive protein (CRP) as the target antigen, we found that anti-CRP-conjugated NDs exhibited high colloidal stability over 1 month at 4 °C in buffer solution. The limits of detection for 3 µL of CRP sample solution were 0.06 µg/mL and 1 ng/mL with variation coefficients of less than 10 and 15% for PETIA and SELFIA, respectively. These two methods together provide a detection range of 1 ng/mL-10 µg/mL, potentially useful for clinical applications. This work represents the first practical use of rounded monocrystalline NDs as in vitro diagnostic reagents.

Is surface roughness of direct resin composite restorations material and polisher-dependent? A systematic review.

STATEMENT OF PROBLEM: Direct resin composite bonding offers a highly esthetic, minimally invasive option for the treatment of anterior teeth however the challenge to improve their longevity remains. Direct resin composite restorations are limited by the risk of staining which may be influenced by the final surface roughness (Ra) of composite achieved. PURPOSE: The purpose of this review is to investigate, using a systematic approach, whether the final surface roughness of anterior composite restorations is affected by the interaction between resin composite and polishing systems. MATERIALS AND METHODS: The review was conducted by 3 independent reviewers and included articles published up to January 21, 2021. Three electronic databases were searched: Medline, Embase, and Web of Science. Studies assessing a quantitative effect of polishing methods on the Ra of direct composite resin materials published after the year 2000 and restricted to the English language were included. RESULTS: The database search for the effect of polishing systems on composite materials retrieved 125 eligible studies. Twelve duplicate records were removed. The resulting records were screened using title and abstract leading to 38 reports which were sought for retrieval. Application of eligibility criteria led to 11 studies included in the review. Hand searching of these studies yielded no additional papers. CONCLUSIONS: There is insufficient evidence to determine whether combination of composite and polisher influences final Ra. More research is required to determine if there is an optimum combination of polisher and composite. CLINICAL IMPLICATIONS: Polishing should be completed following planned finishing procedures. The approximation to the final surface and which finishing burs to use, if any, should be considered when planning a restoration. Durafill VS predictably achieves an acceptable Ra by different polishers.

Modulation of implants PEEK to composite resin shear bond strength and surface roughness on pre-treatment with contemporary air abrasion techniques vs photodynamic therapy vs conventional diamond grit bur.

AIM: The chief aim of the study was to determine/equate the surface roughness (SRa) and shear bond strength (BS) of pretreated PEEK discs with contemporary air abrasion techniques, photodynamic (PD) therapy by curcumin photosensitizer (PS) and conventional diamond grit straight fissure bur adhered to the composite resin discs. MATERIAL AND METHOD: Two hundred discs of PEEK were prepared of 6 mm × 2 mm × 10 mm dimension. The discs were randomly divided into five groups (n = 40) for treatment, Group I: treatment with deionized distilled water (control group); Group II: PD therapy using curcumin PS; Group III: discs treated and abraded with air-borne particles (ABP) silica (30 µm particle size) modified alumina (Al); Group IV: ABP of alumina (110 µm particle size); and Group V: The PEEK were finished with 600-µm grit size straight diamond cutting bur installed in high speed hand-piece. The surface profilometer was used to evaluate the values of surface roughness (SRa) of pretreated PEEK discs. The discs were luted and bonded to discs of composite resin. The bonded PEEK samples were placed in Universal testing machine to evaluate shear BS. The type of BS failure for PEEK discs pre-treated with five regimes respectively was evaluated under stereo-microscope. The data was statistically analyzed using one-way ANOVA and the comparisons between mean values of shear BS were evaluated by Tukey's test (ρ≤0.05). RESULTS: The PEEK samples pre-treated with diamond cutting straight fissure burs displayed statistically significant highest value of SRa values (3.258± 0.785 µm). Similarly, the shear BS was observed to be higher for the PEEK discs pre-treated with straight fissure bur (22.37±0.78 MPa). A comparable difference but not statistically significant difference was observed between PEEK discs pre-treated by curcumin PS and ABP-silica modified alumina (ρ ≥ 0.05). CONCLUSION: PEEK discs pre-treated with diamond grit straight fissure bur displayed highest values of SRa and shear BS. It was trailed by ABP-Al pre-treated discs; whereas the SRa and shear BS values for the discs pre-treated with ABP-silica modified Al and curcumin PS did not show competitive difference.

Leaching kinetic mechanism of iron from the diamond wire saw silicon powder by HCl.

The diamond wire saw silicon powder (DWSSP) is considered to be a harmful to the environment because of finer particles, the large specific surface area and flammability. Removal of Fe impurity is very essential for recovering Si from DWSSP due to the large amount of Fe introduced during the silicon powder generation process. In the study, the thermodynamics of Fe leaching with HCl was analyzed and determined iron was theoretically present as ions in solution. Furthermore, the effects of different concentrations, temperatures and liquid-solid ratios on Fe leaching from HCl were investigated. The leaching rate of Fe reached 98.37% at the optimal parameters (HCl concentration of 12 wt%, leaching temperature of 333 K, liquid-solid ratio of 15 ml/g) with 100 min. The leaching kinetics of Fe in HCl was analyzed by shrinking core model and homogeneous model, respectively. The study indicated the process of leaching Fe from DWSSP conforms to the secondary reaction model of homogeneous model which coincided with the porous structure of DWSSP due to agglomeration. The apparent activation energy required (49.398 kJ/mol) in the first stage is lower than that (57.817 kJ/mol) in the second stage because of the porous structure. In conclusion, this paper provided a suitable way to purify the diamond wire saw silicon powder. This work provides an important guide for the industrial recovery and preparation of high purity silicon from DWSSP by the most environment-friendly and low-cost approach.

Diamonds in the not-so-rough: Wild relative diversity hidden in crop genomes.

Crop production is becoming an increasing challenge as the global population grows and the climate changes. Modern cultivated crop species are selected for productivity under optimal growth environments and have often lost genetic variants that could allow them to adapt to diverse, and now rapidly changing, environments. These genetic variants are often present in their closest wild relatives, but so are less desirable traits. How to preserve and effectively utilize the rich genetic resources that crop wild relatives offer while avoiding detrimental variants and maladaptive genetic contributions is a central challenge for ongoing crop improvement. This Essay explores this challenge and potential paths that could lead to a solution.

The influences of surface effect and elastic strain energy on structure and mechanical properties of dislocations in several diamond- and sphalerite-structured materials.

The fundamental properties of dislocations in diamond-structured Si and sphalerite-structured GaAs, InP and CdTe are investigated based on lattice theory of dislocation, hoping to provide some theoretical references in improving the properties of related materials. The influences of the surface effect(SE) and elastic strain energy on the structure and mechanical property of dislocation are discussed systematically. After considering the SE, the core width of dislocation becomes wider due to the elastic interaction between atoms becomes stronger. Compared to glide partial dislocation, the correction of SE to shuffle dislocation is more obvious. Both the SE and the elastic strain energy affect the energy barrier and Peierls stress of dislocation. The influence of SE on energy barrier and Peierls stress mainly results from the misfit energy and elastic strain energy become lower when the core of dislocation becomes wider. While the influence of elastic strain energy on energy barrier and Peierls stress mainly results from the cancellation between misfit energy and elastic strain energy for they possess comparable amplitudes but opposite phases. In addition, it is deduced that for the studied crystals, the shuffle dislocations control the deformation at medium and low temperatures, while glide partial dislocations are responsible for high temperature plasticity.

Temperature-Dependent Spin-Lattice Relaxation of the Nitrogen-Vacancy Spin Triplet in Diamond.

Spin-lattice relaxation within the nitrogen-vacancy (NV) center's electronic ground-state spin triplet limits its coherence times, and thereby impacts its performance in quantum applications. We report measurements of the relaxation rates on the NV center's |m_{s}=0⟩↔|m_{s}=±1⟩ and |m_{s}=-1⟩↔|m_{s}=+1⟩ transitions as a function of temperature from 9 to 474 K in high-purity samples. We show that the temperature dependencies of the rates are reproduced by an ab initio theory of Raman scattering due to second-order spin-phonon interactions, and we discuss the applicability of the theory to other spin systems. Using a novel analytical model based on these results, we suggest that the high-temperature behavior of NV spin-lattice relaxation is dominated by interactions with two groups of quasilocalized phonons centered at 68.2(17) and 167(12) meV.

Stoichiometric Ternary Superhydride LaBeH_{8} as a New Template for High-Temperature Superconductivity at 110 K under 80 GPa.

The search for high-temperature superconducting superhydrides has recently moved into a new phase by going beyond extensively probed binary compounds and focusing on ternary ones with vastly expanded material types and configurations for property optimization. Theoretical and experimental works have revealed promising ternary compounds that superconduct at or above room temperature, but it remains a pressing challenge to synthesize stoichiometric ternary compounds with a well-resolved crystal structure that can host high-temperature superconductivity at submegabar pressures. Here, we report on the successful synthesis of ternary LaBeH_{8} obtained via compression in a diamond anvil cell under 110-130 GPa. X-ray diffraction unveils a rocksalt-like structure composing La and BeH_{8} units in the lattice. Transport measurements determined superconductivity with critical temperature T_{c} up to 110 K at 80 GPa, as evidenced by a sharp drop of resistivity to zero and a characteristic shift of T_{c} driven by a magnetic field. Our experiment establishes the first superconductive ternary compound with a resolved crystal structure. These findings raise the prospects of rational development of the class of high-T_{c} superhydrides among ternary compounds, opening greatly expanded and more diverse structural space for exploration and discovery of superhydrides with enhanced high-T_{c} superconductivity.

Measuring the Electrical Resistivity of Liquid Iron to 1.4 Mbar.

We determined the electrical resistivity of liquid Fe to 135 GPa and 6680 K using a four-probe method in a diamond-anvil cell combined with two novel techniques: (i) enclosing a molten Fe in a sapphire capsule, and (ii) millisecond time-resolved simultaneous measurements of the resistance, x-ray diffraction, and temperature of instantaneously melted Fe. Our results show the minimal temperature dependence of the resistivity of liquid Fe and its anomalous resistivity decrease around 50 GPa, likely associated with a gradual magnetic transition, both in agreement with previous ab initio calculations.

Spacetime Structure, Asymptotic Radiation, and Information Recovery for a Quantum Hybrid State.

A hybrid quantum state is a combination of the Hartle-Hawking state for the physical particles and the Boulware state for the nonphysical ones (such as ghosts), as was introduced in our earlier work [Y. Potaux et al., Phys. Rev. D 105, 025015 (2022).PRVDAQ2470-001010.1103/PhysRevD.105.025015]. We present a two-dimensional example, based on the Russo-Susskind-Thorlacius model, when the corresponding backreacted spacetime is a causal diamond, geodesically complete and free of the curvature singularities. In the static case it shows no presence of the horizon while it has a wormhole structure mimicking the black hole. In the dynamical case, perturbed by a pulse of classical matter, there appears an apparent horizon while the spacetime remains to be a regular causal diamond. We compute the asymptotic radiation both in the static and dynamical case. We define entropy of the asymptotic radiation and demonstrate that as a function of the retarded time it shows the behavior typical for the Page curve. We suggest interpretation of our findings.

Shear bond strengths of bur or Er:YAG laser prepared dentine to composite resin with or without low-level laser conditioning: an in vitro study.

This study aims to compare the different modes of cavity preparation while evaluating the effect of low-level laser therapy (LLLT) on dentine before bonding in terms of shear bond strength between composite resin and dentine. Fifty human molar teeth were mounted on acrylic blocks and dentine specimen were prepared after which they were randomized into four equal groups. Cavity preparation mode differed in respective groups. After etching, bonding; composite resin was placed and polymerized on the prepared dentine surfaces. The specimens were kept in an environment simulating oral cavity and then shear tested in a universal testing machine. The failure surfaces of the specimen teeth were subjected to SEM micrographic evaluation. The cavity prepared with diamond abrasive points had a higher shearing load at failure that was statistically significantly different from the ones prepared with laser. That with diamond abrasive points followed by LLLT of the cavity surface with Nd:YAG laser had a higher bond strength than the ones prepared with just Er:YAG laser and there was no statistically significant difference between these and the ones prepared with diamond abrasive points alone. SEM analysis of the failure mode in bur-cut dentine showed the presence of a hybrid layer at the interface. Surface conditioning of the same with Nd:YAG laser before etching suggested a recrystallisation of dentine due to the heat produced. Cavity preparation with Er:YAG laser leads to reduced shear bond strength to adhesive restorative materials when compared with that using burs and high-speed handpiece.

A diamond detector based dosimetric system for instantaneous dose rate measurements in FLASH electron beams.

Objective.A reliable determination of the instantaneous dose rate (I-DR) delivered in FLASH radiotherapy treatments is believed to be crucial to assess the so-called FLASH effect in preclinical and biological studies. At present, no detectors nor real-time procedures are available to do that in ultra high dose rate (UH-DR) electron beams, typically consisting ofµs pulses characterized by I-DRs of the order of MGy/s. A dosimetric system is proposed possibly overcoming the above reported limitation, based on the recently developed flashDiamond (fD) detector (model 60025, PTW-Freiburg, Germany).Approach.A dosimetric system is proposed, based on a flashDiamond detector prototype, properly modified and adapted for very fast signal transmission. It was used in combination with a fast transimpedance amplifier and a digital oscilloscope to record the temporal traces of the pulses delivered by an ElectronFlash linac (SIT S.p.A., Italy). The proposed dosimetric systems was investigated in terms of the temporal characteristics of its response and the capability to measure the absolute delivered dose and instantaneous dose rate (I-DR). A 'standard' flashDiamond was also investigated and its response compared with the one of the specifically designed prototype.Main results. Temporal traces recorded in several UH-DR irradiation conditions showed very good signal to noise ratios and rise and decay times of the order of a few tens ns, faster than the ones obtained by the current transformer embedded in the linac head. By analyzing such signals, a calibration coefficient was derived for the fD prototype and found to be in agreement within 1% with the one obtained under reference60Co irradiation. I-DRs as high as about 2 MGy s-1were detected without any undesired saturation effect. Absolute dose per pulse values extracted by integrating the I-DR signals were found to be linear up to at least 7.13 Gy and in very good agreement with the ones obtained by connecting the fD to a UNIDOS electrometer (PTW-Freiburg, Germany). A good short term reproducibility of the linac output was observed, characterized by a pulse-to-pulse variation coefficient of 0.9%. Negligible differences were observed when replacing the fD prototype with a standard one, with the only exception of a somewhat slower response time for the latter detector type.Significance.The proposed fD-based system was demonstrated to be a suitable tool for a thorough characterization of UH-DR beams, providing accurate and reliable time resolved I-DR measurements from which absolute dose values can be straightforwardly derived.

Advances in Stabilization and Enrichment of Shallow Nitrogen-Vacancy Centers in Diamond for Biosensing and Spin-Polarization Transfer.

Negatively charged nitrogen-vacancy (NV-) centers in diamond have unique magneto-optical properties, such as high fluorescence, single-photon generation, millisecond-long coherence times, and the ability to initialize and read the spin state using purely optical means. This makes NV- centers a powerful sensing tool for a range of applications, including magnetometry, electrometry, and thermometry. Biocompatible NV-rich nanodiamonds find application in cellular microscopy, nanoscopy, and in vivo imaging. NV- centers can also detect electron spins, paramagnetic agents, and nuclear spins. Techniques have been developed to hyperpolarize 14N, 15N, and 13C nuclear spins, which could open up new perspectives in NMR and MRI. However, defects on the diamond surface, such as hydrogen, vacancies, and trapping states, can reduce the stability of NV- in favor of the neutral form (NV0), which lacks the same properties. Laser irradiation can also lead to charge-state switching and a reduction in the number of NV- centers. Efforts have been made to improve stability through diamond substrate doping, proper annealing and surface termination, laser irradiation, and electric or electrochemical tuning of the surface potential. This article discusses advances in the stabilization and enrichment of shallow NV- ensembles, describing strategies for improving the quality of diamond devices for sensing and spin-polarization transfer applications. Selected applications in the field of biosensing are discussed in more depth.