Brant Gibson

An organic fluorophore-nanodiamond hybrid sensor for photostable imaging and orthogonal, on-demand biosensing.

Publisher: Springer Science and Business Media LLC

Date: 21-11-2017

DOI: 10.1038/S41598-017-15772-0

Abstract: Organic fluorescent probes are widely used to detect key biomolecules however, they often lack the photostability required for extended intracellular imaging. Here we report a new hybrid nanomaterial (peroxynanosensor, PNS), consisting of an organic fluorescent probe bound to a nanodiamond, that overcomes this limitation to allow concurrent and extended cell-based imaging of the nanodiamond and ratiometric detection of hydrogen peroxide. Far-red fluorescence of the nanodiamond offers continuous monitoring without photobleaching, while the green fluorescence of the organic fluorescent probe attached to the nanodiamond surface detects hydrogen peroxide on demand. PNS detects basal production of hydrogen peroxide within M1 polarised macrophages and does not affect macrophage growth during prolonged co-incubation. This nanosensor can be used for extended bio-imaging not previously possible with an organic fluorescent probe, and is spectrally compatible with both Hoechst 33342 and MitoTracker Orange stains for hyperspectral imaging.

A highly efficient two level diamond based single photon source

Publisher: AIP Publishing

Date: 18-05-2009

DOI: 10.1063/1.3141450

Abstract: An unexplored diamond defect center that is found to emit stable single photons at a measured rate of 1.6 MHz at room temperature is reported. The center, identified in chemical vapor deposition grown diamond crystals, exhibits a sharp zero phonon line at 734 nm with a full width at half maximum of ∼4 nm. The photon statistics confirm that the center is a single emitter and provides direct evidence of a true two level single quantum system in diamond.

Depletion of nitrogen-vacancy color centers in diamond via hydrogen passivation

Publisher: AIP Publishing

Date: 13-02-2012

DOI: 10.1063/1.3684612

Abstract: We show reduction in the emission from nitrogen-vacancy (NV) centers in single crystal diamond due to exposure to hydrogen plasmas ranging from 700 °C to 1000 °C. Significant fluorescence reduction was observed beneath the exposed surface to 80 μm depth after ∼10 min and did not recover after post-annealing in vacuum for 7 h at 1100 °C. We attribute the fluorescence reduction to the formation of nitrogen-vacancy-hydrogen centers by the plasma-induced diffusion of hydrogen. These results have important implications for the formation of NV centers for quantum applications, whilst also providing experimental evidence of long range hydrogen diffusion through intrinsic high-purity diamond.

Self-assembled porphyrin microrods and observation of structure-induced iridescence

Publisher: Royal Society of Chemistry (RSC)

Date: 2010

DOI: 10.1039/B917695K

Air-clad optical fibre filament for generating broadband radiation

Publisher: Elsevier BV

Date: 05-2007

DOI: 10.1016/J.OPTCOM.2006.11.053

Two-photon polymerisation 3D printed freeform micro-optics for optical coherence tomography fibre probes

Publisher: Springer Science and Business Media LLC

Date: 04-10-2018

DOI: 10.1038/S41598-018-32407-0

Abstract: Miniaturised optical coherence tomography (OCT) fibre-optic probes have enabled high-resolution cross-sectional imaging deep within the body. However, existing OCT fibre-optic probe fabrication methods cannot generate miniaturised freeform optics, which limits our ability to fabricate probes with both complex optical function and dimensions comparable to the optical fibre diameter. Recently, major advances in two-photon direct laser writing have enabled 3D printing of arbitrary three-dimensional micro/nanostructures with a surface roughness acceptable for optical applications. Here, we demonstrate the feasibility of 3D printing of OCT probes. We evaluate the capability of this method based on a series of characterisation experiments. We report fabrication of a micro-optic containing an off-axis paraboloidal total internal reflecting surface, its integration as part of a common-path OCT probe, and demonstrate proof-of-principle imaging of biological s les.

Polycrystalline Diamond Coating of Additively Manufactured Titanium for Biomedical Applications

Publisher: American Chemical Society (ACS)

Date: 22-02-2018

DOI: 10.1021/ACSAMI.7B18596

Abstract: Additive manufacturing using selective laser melted titanium (SLM-Ti) is used to create bespoke items across many erse fields such as medicine, defense, and aerospace. Despite great progress in orthopedic implant applications, such as for "just in time" implants, significant challenges remain with regards to material osseointegration and the susceptibility to bacterial colonization on the implant. Here, we show that polycrystalline diamond coatings on these titanium s les can enhance biological scaffold interaction improving medical implant applicability. The highly conformable coating exhibited excellent bonding to the substrate. Relative to uncoated SLM-Ti, the diamond coated s les showed enhanced mammalian cell growth, enriched apatite deposition, and reduced microbial S. aureus activity. These results open new opportunities for novel coatings on SLM-Ti devices in general and especially show promise for improved biomedical implants.

Towards characterisation of millimetre length waveguides and new fabrication method for nanoscale diamond photonic structures

Publisher: Elsevier BV

Date: 04-2011

DOI: 10.1016/J.DIAMOND.2011.02.013

Refractive index design and validation for evanescent field power maximization in optical fibre sensors

Publisher: Elsevier BV

Date: 11-2007

DOI: 10.1016/J.OPTCOM.2007.07.039

Diamond in Tellurite Glass: a New Medium for Quantum Information

Publisher: Wiley

Date: 20-04-2011

DOI: 10.1002/ADMA.201100151

Room temperature self-assembly of mixed nanoparticles into photonic structures

Publisher: Springer Science and Business Media LLC

Date: 13-11-2012

DOI: 10.1038/NCOMMS2182

Abstract: Manufacturing complex composites and structures using incompatible materials is central to next-generation technologies. In photonics, silica offers passivity, low loss and robustness, making it the ideal material platform for optical transport. However, these properties partly stem from the high-temperature processing conditions necessary for silica waveguide fabrication, restricting the functionalisation of waveguides to robust inorganic dopants. This means for many sensor and active device applications, large numbers of materials are excluded. These include many organic and carbon systems such as dyes and diamond. Here we propose using intermolecular forces to bind nanoparticles together at room temperature and demonstrate the room-temperature self-assembly of long microwires (length ~7 cm, width ~10 μm) with and without rhodamine B. Further we report on mixed self-assembly of silica and single-photon-emitting nitrogen-vacancy-containing diamond nanoparticles, opening up a new direction in material science.

Magnetically sensitive nanodiamond-doped tellurite glass fibers

Publisher: Springer Science and Business Media LLC

Date: 19-01-2018

DOI: 10.1038/S41598-018-19400-3

Abstract: Traditional optical fibers are insensitive to magnetic fields, however many applications would benefit from fiber-based magnetometry devices. In this work, we demonstrate a magnetically sensitive optical fiber by doping nanodiamonds containing nitrogen vacancy centers into tellurite glass fibers. The fabrication process provides a robust and isolated sensing platform as the magnetic sensors are fixed in the tellurite glass matrix. Using optically detected magnetic resonance from the doped nanodiamonds, we demonstrate detection of local magnetic fields via side excitation and longitudinal collection. This is a first step towards intrinsically magneto-sensitive fiber devices with future applications in medical magneto-endoscopy and remote mineral exploration sensing.

Diamond-based structures to collect and guide light

Publisher: IOP Publishing

Date: 21-02-2011

DOI: 10.1088/1367-2630/13/2/025020

Oxygen-deficient photostable Cu2O for enhanced visible light photocatalytic activity

Publisher: Royal Society of Chemistry (RSC)

Date: 2018

DOI: 10.1039/C7NR08388B

Abstract: Large-scale synthesis of O-deficient Cu 2 O with outstanding visible photoactivity is shown.

Optical properties of silver composite metamaterials

Publisher: Elsevier BV

Date: 05-2007

DOI: 10.1016/J.PHYSB.2006.12.013

Acoustomicrofluidic Concentration and Signal Enhancement of Fluorescent Nanodiamond Sensors

Publisher: American Chemical Society (ACS)

Date: 23-11-2021

DOI: 10.1021/ACS.ANALCHEM.1C03893

Abstract: Diamond nitrogen-vacancy (NV) centers constitute a promising class of quantum nanosensors owing to the unique magneto-optic properties associated with their spin states. The large surface area and photostability of diamond nanoparticles, together with their relatively low synthesis costs, make them a suitable platform for the detection of biologically relevant quantities such as paramagnetic ions and molecules in solution. Nevertheless, their sensing performance in solution is often h ered by poor signal-to-noise ratios and long acquisition times due to distribution inhomogeneities throughout the analyte s le. By concentrating the diamond nanoparticles through an intense microcentrifugation effect in an acoustomicrofluidic device, we show that the resultant dense NV ensembles within the diamond nanoparticles give rise to an order-of-magnitude improvement in the measured acquisition time. The ability to concentrate nanoparticles under surface acoustic wave (SAW) microcentrifugation in a sessile droplet is, in itself, surprising given the well-documented challenge of achieving such an effect for particles below 1 μm in dimension. In addition to a demonstration of their sensing performance, we thus reveal in this work that the reason why the diamond nanoparticles readily concentrate under the SAW-driven recirculatory flow can be attributed to their considerably higher density and hence larger acoustic contrast compared to those for typical particles and cells for which the SAW microcentrifugation flow has been shown to date.

Infrared erbium photoluminescence enhancement in silicon carbide nano-pillars

Publisher: AIP Publishing

Date: 08-10-2021

DOI: 10.1063/5.0055100

Abstract: Color centers that emit light at telecommunication wavelengths are promising candidates for future quantum technologies. A pressing challenge for the broad use of these color centers is the typically low collection efficiency from bulk s les. Here, we demonstrate enhancements of the emission collection efficiency for Er3+ incorporated into 4H-SiC surface nano-pillars fabricated using a scalable top-down approach. Optimal Er ion implantation and annealing strategies are investigated in detail. The substitutional fraction of Er atoms in the SiC lattice is closely correlated with the peak photoluminescence intensity. This intensity is further enhanced via spatial wave-guiding once the surface is patterned with nano-pillars. These results have broad applicability for use with other color centers in SiC and also demonstrate a step toward a scalable protocol for fabricating photonic quantum devices with enhanced emission characteristics.

Near-Surface Spectrally Stable Nitrogen Vacancy Centres Engineered in Single Crystal Diamond

Publisher: Wiley

Date: 25-05-2012

DOI: 10.1002/ADMA.201201074

Abstract: A method for engineering thin (<100 nm) layers of homoepitaxial diamond containing high quality, spectrally stable, isolated nitrogen-vacancy (NV) centres is reported. The photoluminescence excitation linewidth of the engineered NVs are as low as 140 MHz, at temperatures below 12 K, while the spin properties are at a level suitable for quantum memory and spin register applications. This methodology of NV fabrication is an important step toward scalable and practical diamond based photonic devices suitable for quantum information processing.

Fluorescent Nanodiamonds Embedded in Poly-ε-Caprolactone Fibers as Biomedical Scaffolds

Publisher: American Chemical Society (ACS)

Date: 05-11-2020

DOI: 10.1021/ACSANM.0C02103

Effect of Surface Chemistry on the Fluorescence of Detonation Nanodiamonds.

Publisher: American Chemical Society (ACS)

Date: 03-11-2017

DOI: 10.1021/ACSNANO.7B04647

Abstract: Detonation nanodiamonds (DNDs) have unique physical and chemical properties that make them invaluable in many applications. However, DNDs are generally assumed to show weak fluorescence, if any, unless chemically modified with organic molecules. We demonstrate that detonation nanodiamonds exhibit significant and excitation-wavelength-dependent fluorescence from the visible to the near-infrared spectral region above 800 nm, even without the engraftment of organic molecules to their surfaces. We show that this fluorescence depends on the surface functionality of the DND particles. The investigated functionalized DNDs, produced from the same purified DND as well as the as-received polyfunctional starting material, are hydrogen, hydroxyl, carboxyl, ethylenediamine, and octadecylamine-terminated. All DNDs are investigated in solution and on a silicon wafer substrate and compared to fluorescent high-pressure high-temperature nanodiamonds. The brightest fluorescence is observed from octadecylamine-functionalized particles and is more than 100 times brighter than the least fluorescent particles, carboxylated DNDs. The majority of photons emitted by all particle types likely originates from non-diamond carbon. However, we locally find bright and photostable fluorescence from nitrogen-vacancy centers in diamond in hydrogenated, hydroxylated, and carboxylated detonation nanodiamonds. Our results contribute to understanding the effects of surface chemistry on the fluorescence of DNDs and enable the exploration of the fluorescent properties of DNDs for applications in theranostics as nontoxic fluorescent labels, sensors, nanoscale tracers, and many others where chemically stable and brightly fluorescent nanoparticles with tailorable surface chemistry are needed.

Proximal nitrogen reduces the fluorescence quantum yield of nitrogen-vacancy centres in diamond

Publisher: IOP Publishing

Date: 03-2022

DOI: 10.1088/1367-2630/AC5CA9

Abstract: The nitrogen-vacancy colour centre in diamond is emerging as one of the most important solid-state quantum systems. It has applications to fields including high-precision sensing, quantum computing, single photon communication, metrology, nanoscale magnetic imaging and biosensing. For all of these applications, a high quantum yield of emitted photons is desirable. However, diamond s les engineered to have high densities of nitrogen-vacancy centres show levels of brightness varying significantly within single batches, or even within the same s le. Here we show that nearby nitrogen impurities quench emission of nitrogen-vacancy centres via non-radiative transitions, resulting in a reduced fluorescence quantum yield. We monitored the emission properties of nitrogen-vacancy centre ensembles from synthetic diamond s les with different concentrations of nitrogen impurities. All s les were irradiated with high energy electrons to create high densities of nitrogen-vacancy centres relative to the concentration of nitrogen impurities. While at low nitrogen densities of 1.81 ppm we measured a lifetime of 13.9 ns, we observed a strong reduction in lifetime with increasing nitrogen density. We measure a lifetime as low as 4.4 ns at a nitrogen density of 380 ppm. The change in lifetime matches a reduction in relative fluorescence quantum yield from 77.4% to 32% with an increase in nitrogen density from 88 ppm to 380 ppm, respectively. These results will inform the conditions required to optimise the properties of diamond crystals devices based on the fluorescence of nitrogen-vacancy centres. Furthermore, this work provides insights into the origin of inhomogeneities observed in high-density nitrogen-vacancy ensembles within diamonds and nanodiamonds.

Accessing diamond waveguides and future applications

Publisher: SPIE

Date: 11-02-2010

DOI: 10.1117/12.843013

Visitors' wayfinding strategies and navigational aids in unfamiliar urban environment

Publisher: Informa UK Limited

Date: 12-2019

DOI: 10.1080/14616688.2019.1696883

Optical properties of neodymium ions in nanoscale regions of gallium nitride: erratum

Publisher: The Optical Society

Date: 25-01-2021

DOI: 10.1364/OME.420328

Fluorescent Silicon Carbide Nanoparticles

Publisher: Wiley

Date: 17-07-2021

DOI: 10.1002/ADOM.202100311

Abstract: Silicon carbide (SiC) is an indirect wide band gap semiconductor that is utilized in many industrial applications due to its extreme physical properties. SiC nanoparticles (NPs) exhibit a versatile surface chemistry, fluoresce from the ultraviolet to the near‐infrared spectral ranges, and their sizes can be tuned from one to hundreds of nanometers. Yet, fluorescent SiC NPs have received far less attention by the scientific community. This review summarizes the state‐of‐the‐art in fluorescent SiC NPs. Nanoparticle fabrication methods, characterization techniques, nanoparticle surface chemistry, and SiC NPs fluorescence properties are assessed in detail. Atomic defects and impurities in the SiC crystal lattice (so‐called color centers), surface‐induced fluorescence, quantum confinement, and band‐edge fluorescence are identified as the main sources of fluorescence in SiC NPs. While many color centers are reported in bulk SiC, only few are identified in SiC NPs and interface‐related defects remain poorly understood, creating enormous potential for scientific discovery. Finally, an overview of demonstrated and emerging potential applications of SiC NPs in the areas of bioimaging and quantum sensing is provided.

Magnetic field-induced enhancement of the nitrogen-vacancy fluorescence quantum yield

Publisher: Royal Society of Chemistry (RSC)

Date: 2017

DOI: 10.1039/C7NR02093G

Abstract: The nitrogen-vacancy (NV) centre in diamond is a remarkable optical defect with broad applications. We demonstrate that its fluorescence emission is enhanced at high magnetic fields with low excitation power.

3D-Printed Diamond–Titanium Composite: A Hybrid Material for Implant Engineering

Publisher: American Chemical Society (ACS)

Date: 24-12-2019

DOI: 10.1021/ACSABM.9B00801

Abstract: Diamond-based implant materials make up an emerging research area where the materials could be prepared to promote cellular functions, decrease bacteria attachment, and be suitable for potential

Critical components for diamond-based quantum coherent devices

Publisher: IOP Publishing

Date: 12-05-2006

DOI: 10.1088/0953-8984/18/21/S09

Towards all-diamond optical devices

Publisher: IEEE

Date: 06-2010

DOI: 10.1109/ICTON.2010.5548938

Imaging and quantum-efficiency measurement of chromium emitters in diamond

Publisher: American Physical Society (APS)

Date: 16-11-2010

DOI: 10.1103/PHYSREVLETT.105.217403

UV plasmonic properties of colloidal liquid-metal eutectic gallium-indium alloy nanoparticles

Publisher: Springer Science and Business Media LLC

Date: 29-03-2019

DOI: 10.1038/S41598-019-41789-8

Abstract: Nanoparticles made of non-noble metals such as gallium have recently attracted significant attention due to promising applications in UV plasmonics. To date, experiments have mostly focused on solid and liquid pure gallium particles immobilized on solid substrates. However, for many applications, colloidal liquid-metal nanoparticle solutions are vital. Here, we experimentally demonstrate strong UV plasmonic resonances of eutectic gallium-indium (EGaIn) liquid-metal alloy nanoparticles suspended in ethanol. We rationalise experimental results through a theoretical model based on Mie theory. Our results contribute to the understanding of UV plasmon resonances in colloidal liquid-metal EGaIn nanoparticle suspensions. They will also enable further research into emerging applications of UV plasmonics in biomedical imaging, sensing, stretchable electronics, photoacoustics, and electrochemistry.

Evanescent field analysis of air-silica microstructure waveguides [for biosensing applications]

Publisher: IEEE

Date: 2001

DOI: 10.1109/LEOS.2001.969011

Fluorescence brightness and photostability of individual copper (I) oxide nanocubes

Publisher: Springer Science and Business Media LLC

Date: 04-12-2017

DOI: 10.1038/S41598-017-17295-0

Abstract: Conventional organic fluorophores lose their ability to fluoresce after repeated exposure to excitation light due to photobleaching. Therefore, research into emerging bright and photostable nanomaterials has become of great interest for a range of applications such as bio-imaging and tracking. Among these emerging fluorophores, metal oxide-based nanomaterials have attracted significant attention as a potential multifunctional material with photocatalytic and angeogenisis abilities in addition to fluorescnce applications. However, most of these applications are highly dependent on size, morphology, and chemo-physical properties of in idual particles. In this manuscript, we present a method to study the intrinsic optical characteristics of in idual copper (I) oxide (Cu 2 O) nanocubes. When excited at 520 nm using only 11 µW excitation power (1.7 W/cm2), in idual nanocubes were observed to emit light with peak wavelengths ~760 nm which is conveniently within the near-infrared 1 (NIR1) biological window where tissue autofluorescence is minimal. Bright and photostable fluorescence was observed with intensities up to 487 K counts/s under constant illumination for at least 2 minutes with a brightness approximately four times higher than the autofluorescence from a fixed cumulus-oocyte complex. With near-IR emission, high fluorescence brightness, and outstanding photostability, Cu 2 O nanocubes are attractive candidates for long-term fluorescent bioimaging applications.

Electrospun Nanodiamond-Silk Fibroin Membranes: A Multifunctional Platform for Biosensing and Wound-Healing Applications

Publisher: American Chemical Society (ACS)

Date: 13-10-2020

DOI: 10.1021/ACSAMI.0C15612

Optical properties of neodymium ions in nanoscale regions of gallium nitride: erratum

Publisher: The Optical Society

Date: 25-01-2021

DOI: 10.1364/OME.11.000524

Ion-Beam-Assisted Lift-Off Technique for Three-Dimensional Micromachining of Freestanding Single-Crystal Diamond

Publisher: Wiley

Date: 17-10-2005

DOI: 10.1002/ADMA.200500752

MPCVD Processing of Titanium-diffused LiNbO<inf>3</inf> Waveguides: Optical Characterisation and Waveguide Restoration

Publisher: IEEE

Date: 12-2006

DOI: 10.1109/COMMAD.2006.4429929

The effect of particle size on nanodiamond fluorescence and colloidal properties in biological media

Publisher: IOP Publishing

Date: 08-07-2019

DOI: 10.1088/1361-6528/AB283D

Abstract: Fluorescent nanodiamonds (FNDs) are extremely photostable markers and nanoscale sensors, which are increasingly used in biomedical applications. Nanoparticle size is a critical parameter in the majority of these applications. Yet, the effect of particle size on FND's fluorescence and colloidal properties is not well understood today. Here, we investigate the fluorescence and colloidal stability of commercially available high-pressure high-temperature FNDs containing nitrogen-vacancy (NV) centers in biological media. Unconjugated FNDs in sizes ranging between 10 nm and 140 nm with an oxidized surface are studied using dynamic light scattering and fluorescence spectroscopy. We determine their colloidal stability in water, fetal bovine serum, Dulbecco's Modified Eagle Medium and complete media. The FNDs' relative fluorescence brightness, the NV charge-state, and the FND fluorescence against media autofluorescence are analyzed as a function of FND size. Our results will enable researchers in biology and beyond to identify the most promising FND particle size for their application.

Single-Photon Emission and Quantum Characterization of Zinc Oxide Defects

Publisher: American Chemical Society (ACS)

Date: 24-01-2012

DOI: 10.1021/NL204010E

Abstract: Room temperature single-photon emission and quantum characterization is reported for isolated defects in zinc oxide. The defects are observed in thin films of both in-house synthesized and commercial zinc oxide nanoparticles. Emission spectra in the red and infrared, second-order photon correlation functions, lifetime measurements, and photon count rates are presented. Both two- and three-state emitters are identified. Sub-band gap absorption and red emission suggest these defects are the zinc vacancy. These results identify a new source of single photons in a readily available wide band gap semiconductor material which has exceptional electrical, optical, and biocompatibility properties.

Grandparents fostering orphans: influences of protective factors on their health and well-being.

Publisher: Informa UK Limited

Date: 10-07-2014

DOI: 10.1080/07399332.2014.916294

Abstract: In this study the authors explore the impact of protective factors on the health and well-being of grandmothers who are primary caregivers. Although researchers in Africa have studied grandparents who assume primary caregiving responsibilities, it is rare that they do so from a strength perspective, hence the need to examine the utility of personal, social, and environmental assets on caregiving. Grandmothers are the primary caregivers of orphaned children due to HIV and AIDS deaths thus it becomes pertinent to establish how they are coping without the provision of social security. The results of this study will be beneficial to all stakeholders interested in the welfare of elders with similar responsibilities. Knowledge about the health and well-being of grandmothers who are caregivers will assist public service and private sectors to formulate viable policies concerning elderly carers who foster orphans, particularly in countries with high HIV prevalence.

Diamond waveguides: toward an all-diamond platform

Publisher: SPIE

Date: 21-12-2007

DOI: 10.1117/12.769906

Focused ion beam processing and engineering of devices in self-assembled supramolecular structures

Publisher: IOP Publishing

Date: 30-10-2009

DOI: 10.1088/0957-4484/20/48/485301

Abstract: Self-assembled supramolecular structures such as optical wires, films and 2D slabs offer a new generation of electronic and optical devices. In particular, self-assembled porphyrin devices, including those integrated onto silica and silicon platforms, open new opportunities in photonic applications spanning molecular biosensing, photovoltaics and telecommunications. All reports to date, however, largely highlight the potential but have not established a clear pathway to the actual implementation of more complex device prototypes. In this paper, we propose and demonstrate the use of a focused ion beam (FIB) to process and fabricate devices in porphyrin-based supramolecular structures. These self-assembled structures have an initial root mean squared (rms) values for surface roughness of < 0.5 nm as measured by atomic force microscopy. Under appropriate FIB processing and cutting conditions, the rms value for surface roughness falls to < 0.4 nm, comparable with some of the best optical flatnesses obtained within, for ex le, structured optical fibres and integrated optical waveguides. The milling rate of the porphyrin structures was estimated to be approximately 70% of that of silica. The versatility of a FIB as a tool for rapid processing and fabricating 1D and 2D photonic waveguide structures within supramolecular self-assembled platforms is demonstrated by fabricating a 2D coupler, setting the groundwork for true optical device engineering and integration using these new organic systems.

Preferential coupling of diamond NV centres in step-index fibres

Publisher: Optica Publishing Group

Date: 28-04-2021

DOI: 10.1364/OE.417825

Abstract: Diamonds containing the negatively charged nitrogen-vacancy centre are a promising system for room-temperature magnetometry. The combination of nano- and micro-diamond particles with optical fibres provides an option for deploying nitrogen-vacancy magnetometers in harsh and challenging environments. Here we numerically explore the coupling efficiency from nitrogen-vacancy centres within a diamond doped at the core/clad interface across a range of commercially available fibre types so as to inform the design process for a diamond in fibre magnetometers. We determine coupling efficiencies from nitrogen-vacancy centres to the guided modes of a step-index fibre and predict the optically detected magnetic resonance (ODMR) generated by a ensemble of four nitrogen-vacancy centres in this hybrid fibre system. Our results show that the coupling efficiency is enhanced with a high refractive index difference between the fibre core and cladding and depends on the radial position of the nitrogen-vacancy centres in the fibre core. Our ODMR simulations show that due to the preferential coupling of the nitrogen-vacancy emission to the fibre guided modes, certain magnetometry features such as ODMR contrast can be enhanced and lead to improved sensitivity in such diamond-fibre systems, relative to conventional diamond only ensemble geometries.

Photoluminescence properties of praseodymium ions implanted into submicron regions in gallium nitride

Publisher: IOP Publishing

Date: 25-04-2019

DOI: 10.7567/1347-4065/AB142B

Characterization of three-dimensional microstructures in single-crystal diamond

Publisher: Elsevier BV

Date: 10-2006

DOI: 10.1016/J.DIAMOND.2006.01.018

Correction to: Vitrification within a nanoliter volume: oocyte and embryo cryopreservation within a 3D photopolymerized device

Publisher: Springer Science and Business Media LLC

Date: 07-09-2022

DOI: 10.1007/S10815-022-02610-0

Photon extraction enhancement of praseodymium ions in gallium nitride nanopillars

Publisher: Springer Science and Business Media LLC

Date: 08-12-2022

DOI: 10.1038/S41598-022-25522-6

Abstract: Lanthanoid-doped Gallium Nitride (GaN) integrated into nanophotonic technologies is a promising candidate for room-temperature quantum photon sources for quantum technology applications. We manufactured praseodymium (Pr)-doped GaN nanopillars of varying size, and showed significantly enhanced room-temperature photon extraction efficiency compared to unstructured Pr-doped GaN. Implanted Pr ions in GaN show two main emission peaks at 650.3 nm and 651.8 nm which are attributed to 3 P 0 - 3 F 2 transition in the 4 f -shell. The maximum observed enhancement ratio was 23.5 for 200 nm diameter circular pillars, which can be ided into the emitted photon extraction enhancement by a factor of 4.5 and the photon collection enhancement by a factor of 5.2. The enhancement mechanism is explained by the eigenmode resonance inside the nanopillar. Our study provides a pathway for Lanthanoid-doped GaN nano/micro-scale photon emitters and quantum technology applications.

Fabrication on the microscale: a two-photon polymerized device for oocyte microinjection

Publisher: Springer Science and Business Media LLC

Date: 12-05-2022

DOI: 10.1007/S10815-022-02485-1

Abstract: Intracytoplasmic sperm injection (ICSI) addresses male sub-fertility by injecting a spermatozoon into the oocyte. This challenging procedure requires the use of dual micromanipulators, with success influenced by inter-operator expertise. We hypothesized that minimizing oocyte handling during ICSI will simplify the procedure. To address this, we designed and fabricated a micrometer scale device that houses the oocyte and requires only one micromanipulator for microinjection. The device consisted of 2 components, each of sub-cubic millimeter volume: a Pod and a Garage. These were fabricated using 2-photon polymerization. Toxicity was evaluated by culturing single-mouse presumptive zygotes (PZs) to the blastocyst stage within a Pod, with several Pods (and embryos) docked in a Garage. The development was compared to standard culture. The level of DNA damage/repair in resultant blastocysts was quantified (γH2A.X immunohistochemistry). To demonstrate the capability to carry out ICSI within the device, PZs were microinjected with 4-μm fluorescent microspheres and cultured to the blastocyst stage. Finally, the device was assessed for oocyte traceability and high-throughput microinjection capabilities and compared to standard microinjection practice using key parameters (pipette setup, holding then injecting oocytes). Compared to standard culture, embryo culture within Pods and a Garage showed no differences in development to the blastocyst stage or levels of DNA damage in resultant blastocysts. Furthermore, microinjection within our device removes the need for a holding pipette, improves traceability, and facilitates high-throughput microinjection. This novel device could improve embryo production following ICSI by simplifying the procedure and thus decreasing inter-operator variability.

Fabrication of Ultrathin Single‐Crystal Diamond Membranes

Publisher: Wiley

Date: 16-12-2008

DOI: 10.1002/ADMA.200801460

Targeting cell surface glycans with lectin-coated fluorescent nanodiamonds

Publisher: Royal Society of Chemistry (RSC)

Date: 2022

DOI: 10.1039/D2NA00036A

Abstract: Nanodiamonds were coated in lectins to target glycan receptors on astrocytes, neurons and microglia. The uptake in each cell type was variable depending on their coating of Aleuria aurantia lectin, wheat germ agglutinin or tomato lectin.

A Telecom O-Band Emitter in Diamond

Publisher: American Chemical Society (ACS)

Date: 29-03-2023

DOI: 10.1021/ACS.NANOLETT.2C04608

Optical properties of nanoscale annular array metamaterials

Publisher: SPIE

Date: 31-08-2006

DOI: 10.1117/12.679210

Plasmonic nanoresonant materials

Publisher: SPIE

Date: 21-12-2007

DOI: 10.1117/12.772641

Near Infrared Photoluminescence of N_CV_Si^- Centers in High-Purity Semi-Insulating 4H-SiC Irradiated with Energetic Charged Particles

Publisher: Trans Tech Publications, Ltd.

Date: 07-2020

DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.1004.355

Abstract: This paper reports optical propertites of negatively charged N C V Si - centers in silicon carbide (a nitrogen substituting for a carbon atom adjacent to a silicon vacancy) whose emission wavlength is 1100-1500 nm at room temperature. High-purity semi-insulating (HPSI) 4H-SiCs are implanted with high energy N ion beams and subsequently thermally annealed to form N C V Si centers. We investigated a wide range of N ion implantation dose using a micro ion beam implantation technique and observed the photoluminescence intensity from the SiC-NV centers. We show that under conditions of heavy implantation, the excitation laser power excites residual defects and their fluorescences intereferes with the emission from the N C V Si - centers. These results allow us to clarify the requirements to optically detect isolated single N C V Si - centers at lightly implanted conditions.

Visible to near-IR fluorescence from single-digit detonation nanodiamonds: excitation wavelength and pH dependence

Publisher: Springer Science and Business Media LLC

Date: 06-02-2018

DOI: 10.1038/S41598-018-20905-0

Abstract: Detonation nanodiamonds are of vital significance to many areas of science and technology. However, their fluorescence properties have rarely been explored for applications and remain poorly understood. We demonstrate significant fluorescence from the visible to near-infrared spectral regions from deaggregated, single-digit detonation nanodiamonds dispersed in water produced via post-synthesis oxidation. The excitation wavelength dependence of this fluorescence is analyzed in the spectral region from 400 nm to 700 nm as well as the particles’ absorption characteristics. We report a strong pH dependence of the fluorescence and compare our results to the pH dependent fluorescence of aromatic hydrocarbons. Our results significantly contribute to the current understanding of the fluorescence of carbon-based nanomaterials in general and detonation nanodiamonds in particular.

High-fat diet worsens the impact of aging on microglial function and morphology in a region-specific manner

Publisher: Elsevier BV

Date: 02-2019

DOI: 10.1016/J.NEUROBIOLAGING.2018.10.018

Not All Fluorescent Nanodiamonds Are Created Equal: A Comparative Study

Publisher: Wiley

Date: 28-01-2019

DOI: 10.1002/PPSC.201900009

Temporal Model of the Drivers of Household PV Purchase in Australia

Publisher: Springer Science and Business Media LLC

Date: 14-09-2019

DOI: 10.1007/S40866-019-0068-Y

Optical properties of neodymium ions in nanoscale regions of gallium nitride

Publisher: Optica Publishing Group

Date: 18-09-2020

DOI: 10.1364/OME.401765

Abstract: Wide bandgap semiconductors are increasingly important for bioimaging applications, as they can possess good biocompatibility and host a large range of fluorescent defects spanning the visible to infrared. Gallium nitride is one promising host for photostable fluorophores. In particular, neodymium (Nd)-doped gallium nitride (GaN) shows bright near-infrared fluorescence and narrow room temperature linewidth and is therefore a candidate material for fluorescent probes for bioimaging. To explore the conditions necessary to generate biomarkers based on Nd:GaN, this paper reports the room temperature photoluminescence (PL) properties of small ensembles of Nd ions implanted into the nanoscale regions of GaN epilayers. The minimum volume of Nd-implanted GaN that can be optically detected in this study is about 8×10 4 nm 3 and the minimum detected ensemble of Nd ions is about 4×10 3 , although not all of implanted Nd ions activate as luminescence centers. We show from the PL excitation spectra that the strongest resonant excitation appears at 619 nm, attributed to the 4 I 9/2 → 4 G 5/2 ( 4 G 7/2 ) transition in the 4 f -shell. We measure the luminescence lifetime to be several tens of microseconds. We also identify the presence of a different excitation mechanism from the resonant excitation when excited below 510 nm (above 2.43 eV).

Optical fiber bundles: Ultra-slim light field imaging probes

Publisher: American Association for the Advancement of Science (AAAS)

Date: 05-04-2019

DOI: 10.1126/SCIADV.AAV1555

Abstract: Light field microscopy through bare optical fiber bundles paves the way for depth-resolved fluorescence microendoscopy.

Magnetic-field-dependent stimulated emission from nitrogen-vacancy centers in diamond

Publisher: American Association for the Advancement of Science (AAAS)

Date: 03-06-2022

DOI: 10.1126/SCIADV.ABN7192

Abstract: Negatively charged nitrogen-vacancy (NV) centers in diamond are promising magnetic field quantum sensors. Laser threshold magnetometry theory predicts improved NV center ensemble sensitivity via increased signal strength and magnetic field contrast. Here, we experimentally demonstrate laser threshold magnetometry. We use a macroscopic high-finesse laser cavity containing a highly NV-doped and low absorbing diamond gain medium that is pumped at 532 nm and resonantly seeded at 710 nm. This enables a 64% signal power lification by stimulated emission. We test the magnetic field dependency of the lification and thus demonstrate magnetic field–dependent stimulated emission from an NV center ensemble. This emission shows an ultrahigh contrast of 33% and a maximum output power in the milliwatt regime. The coherent readout of NV centers pave the way for novel cavity and laser applications of quantum defects and diamond NV magnetic field sensors with substantially improved sensitivity for the health, research, and mining sectors.

Reactive ion etching of waveguide structures in diamond

Publisher: Elsevier BV

Date: 11-2008

DOI: 10.1016/J.DIAMOND.2008.04.019

Engineering the Interface: Nanodiamond Coating on 3D-Printed Titanium Promotes Mammalian Cell Growth and Inhibits Staphylococcus aureus Colonization

Publisher: American Chemical Society (ACS)

Date: 14-06-2019

DOI: 10.1021/ACSAMI.9B07064

Abstract: Additively manufactured selective laser melted titanium (SLM-Ti) opens the possibility of tailored medical implants for patients. Despite orthopedic implant advancements, significant problems remain with regard to suboptimal osseointegration at the interface between the implant and the surrounding tissue. Here, we show that applying a nanodiamond (ND) coating onto SLM-Ti scaffolds provides an improved surface for mammalian cell growth while inhibiting colonization of

Large-area freestanding gold nanomembranes with nanoholes

Publisher: Royal Society of Chemistry (RSC)

Date: 2019

DOI: 10.1039/C8MH01302K

Abstract: Large-area freestanding gold nanomembranes with nanoholes are created, enabling their property study without substrate effect and emerging applications.

Vitrification within a nanoliter volume: oocyte and embryo cryopreservation within a 3D photopolymerized device

Publisher: Springer Science and Business Media LLC

Date: 11-08-2022

DOI: 10.1007/S10815-022-02589-8

Abstract: Vitrification permits long-term banking of oocytes and embryos. It is a technically challenging procedure requiring direct handling and movement of cells between potentially cytotoxic cryoprotectant solutions. Variation in adherence to timing, and ability to trace cells during the procedure, affects survival post-warming. We hypothesized that minimizing direct handling will simplify the procedure and improve traceability. To address this, we present a novel photopolymerized device that houses the s le during vitrification. The fabricated device consisted of two components: the Pod and Garage . Single mouse oocytes or embryos were housed in a Pod, with multiple Pods docked into a Garage. The suitability of the device for cryogenic application was assessed by repeated vitrification and warming cycles. Oocytes or early blastocyst-stage embryos were vitrified either using standard practice or within Pods and a Garage and compared to non-vitrified control groups. Post-warming, we assessed survival rate, oocyte developmental potential (fertilization and subsequent development) and metabolism (autofluorescence). Vitrification within the device occurred within ~ 3 nL of cryoprotectant: this volume being ~ 1000-fold lower than standard vitrification. Compared to standard practice, vitrification and warming within our device showed no differences in viability, developmental competency, or metabolism for oocytes and embryos. The device housed the s le during processing, which improved traceability and minimized handling. Interestingly, vitrification-warming itself, altered oocyte and embryo metabolism. The Pod and Garage system minimized the volume of cryoprotectant at vitrification—by ~ 1000-fold—improved traceability and reduced direct handling of the s le. This is a major step in simplifying the procedure.

Rationally Designed Probe for Reversible Sensing of Zinc and Application in Cells

Publisher: American Chemical Society (ACS)

Date: 27-09-2017

DOI: 10.1021/ACSOMEGA.7B00923

Fluorescence and Physico-Chemical Properties of Hydrogenated Detonation Nanodiamonds

Publisher: MDPI AG

Date: 07-02-2020

DOI: 10.3390/C6010007

Abstract: Hydrogenated detonation nanodiamonds are of great interest for emerging applications in areas from biology and medicine to lubrication. Here, we compare the two main hydrogenation techniques—annealing in hydrogen and plasma-assisted hydrogenation—for the creation of detonation nanodiamonds with a hydrogen terminated surface from the same starting material. Synchrotron-based soft X-ray spectroscopy, infrared absorption spectroscopy, and electron energy loss spectroscopy were employed to quantify diamond and non-diamond carbon contents and determine the surface chemistries of all s les. Dynamic light scattering was used to study the particles’ colloidal properties in water. For the first time, steady-state and time-resolved fluorescence spectroscopy analysis at temperatures from room temperature down to 10 K was performed to investigate the particles’ fluorescence properties. Our results show that both hydrogenation techniques produce hydrogenated detonation nanodiamonds with overall similar physico-chemical and fluorescence properties.

A dual-mode mobile phone microscope using the onboard camera flash and ambient light

Publisher: Springer Science and Business Media LLC

Date: 19-02-2018

DOI: 10.1038/S41598-018-21543-2

Abstract: Mobile phone microscopes are a natural platform for point-of-care imaging, but current solutions require an externally powered illumination source, thereby adding bulk and cost. We present a mobile phone microscope that uses the internal flash or sunlight as the illumination source, thereby reducing complexity whilst maintaining functionality and performance. The microscope is capable of both brightfield and darkfield imaging modes, enabling microscopic visualisation of s les ranging from plant to mammalian cells. We describe the microscope design principles, assembly process, and demonstrate its imaging capabilities through the visualisation of unlabelled cell nuclei to observing the motility of cattle sperm and zooplankton.

RMIT University

Location: Australia

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Discovery Projects - Grant ID: DP220102518

Start Date: 11-2022

End Date: 11-2025

Amount: $400,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP120100901

Start Date: 2012

End Date: 12-2016

Amount: $360,000.00

Funder: Australian Research Council

ARC Future Fellowships - Grant ID: FT110100225

Start Date: 2012

End Date: 12-2016

Amount: $664,528.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE140100131

Start Date: 03-2014

End Date: 12-2016

Amount: $500,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP210300230

Start Date: 06-2023

End Date: 06-2026

Amount: $345,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP220103181

Start Date: 09-2022

End Date: 09-2025

Amount: $670,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE180100150

Start Date: 05-2018

End Date: 12-2019

Amount: $595,280.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE230100005

Start Date: 2023

End Date: 12-2023

Amount: $852,787.00

Funder: Australian Research Council

ARC Centres Of Excellence - Grant ID: CE140100003

Start Date: 10-2014

End Date: 12-2020

Amount: $23,000,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE200100098

Start Date: 2020

End Date: 06-2022

Amount: $600,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE150100001

Start Date: 2015

End Date: 12-2015

Amount: $410,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE100100098

Start Date: 06-2010

End Date: 03-2012

Amount: $600,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE190100130

Start Date: 2019

End Date: 12-2019

Amount: $1,480,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE200100186

Start Date: 2020

End Date: 12-2020

Amount: $233,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE130100161

Start Date: 2013

End Date: 12-2016

Amount: $150,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE150100177

Start Date: 2015

End Date: 12-2015

Amount: $440,000.00

Funder: Australian Research Council