ORCID Profile
0000-0003-1549-937X
Current Organisation
RMIT University
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In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Nanomaterials | Quantum Physics | Optical Properties of Materials | Condensed Matter Physics | Nanotechnology | Elemental Semiconductors | Photonic and electro-optical devices sensors and systems (excl. communications) | Electronics sensors and digital hardware | Surfaces and Structural Properties of Condensed Matter | Electronic and Magnetic Properties of Condensed Matter; Superconductivity | Atomic molecular and optical physics not elsewhere classified | Nonlinear Optics and Spectroscopy | Quantum Physics not elsewhere classified | Nonlinear optics and spectroscopy
Expanding Knowledge in the Physical Sciences | Emerging Defence Technologies | Scientific Instruments | Expanding Knowledge in Engineering | Expanding Knowledge in the Biological Sciences |
Publisher: Wiley
Date: 10-03-2010
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.
Publisher: Wiley
Date: 28-10-2017
Publisher: Springer Science and Business Media LLC
Date: 16-01-2017
DOI: 10.1557/ADV.2017.53
Publisher: Wiley
Date: 31-10-2020
Publisher: The Optical Society
Date: 06-06-2018
DOI: 10.1364/BOE.9.002943
Publisher: Elsevier BV
Date: 03-2019
Publisher: Wiley
Date: 28-06-2012
Publisher: American Chemical Society (ACS)
Date: 18-08-2023
Publisher: SPIE
Date: 30-12-2019
DOI: 10.1117/12.2539276
Publisher: Springer Science and Business Media LLC
Date: 13-02-2015
DOI: 10.1038/SREP08443
Abstract: Finding new ways to control and slow down the group velocity of light in media remains a major challenge in the field of optics. For the design of plasmonic slow light structures, graphene represents an attractive alternative to metals due to its strong field confinement, comparably low ohmic loss and versatile tunability. Here we propose a novel nanostructure consisting of a monolayer graphene on a silicon based graded grating structure. An external gate voltage is applied to graphene and silicon, which are separated by a spacer layer of silica. Theoretical and numerical results demonstrate that the structure exhibits an ultra-high slowdown factor above 450 for the propagation of surface plasmon polaritons (SPPs) excited in graphene, which also enables the spatially resolved trapping of light. Slowdown and trapping occur in the mid-infrared wavelength region within a bandwidth of ~2.1 μm and on a length scale less than 1/6 of the operating wavelength. The slowdown factor can be precisely tuned simply by adjusting the external gate voltage, offering a dynamic pathway for the release of trapped SPPs at room temperature. The presented results will enable the development of highly tunable optoelectronic devices such as plasmonic switches and buffers.
Publisher: IOP Publishing
Date: 12-10-2020
Abstract: NaYF 4 is an efficient host material for lanthanide-based upconversion luminescence and has attracted immense interest for potential applications in photovoltaics, lasers and bioimaging. However, being a non-van der Waals (non-vdW) material, there have been thus far no reports on exfoliation of bulk NaYF 4 to nanosheets and their upconversion luminescence properties. Here, we demonstrate for the first time the fabrication of lanthanide-containing NaYF 4 2D nanosheets using a soft liquid-phase exfoliation method and report on their optical, electronic and chemical characteristics. The nanosheets exfoliated from NaYF 4 :Yb,Er microcrystals consisting mainly of β -NaYF 4 become enriched in α -NaYF 4 post exfoliation and have a large micron-sized planar area with a preferential (100) surface orientation. X-ray absorption spectroscopy confirms that both Yb and Er doping ions are retained in the exfoliated nanosheets. Through centrifugation, NaYF 4 2D nanosheets are successfully obtained with thicknesses ranging from a monolayer to tens of layers. Optical analysis of in idual nanosheets shows that they exhibit both optical down-conversion and upconversion properties, albeit with reduced emission intensities compared with the parent microparticles. Further exploration of their electronic structure by density functional theory (DFT) calculations and photoelectron spectroscopy reveals the formation of surface F atom defects and a shrinkage of the electronic bandgap in ultrathin nanosheets. Our findings will trigger further interest in non-vdW 2D upconversion nanomaterials.
Publisher: Wiley
Date: 2010
Abstract: The manipulation and analysis of biomolecules in native bulk solution is highly desired however, few methods are available. In thermophoresis, the thermal analog to electrophoresis, molecules are moved along a microscopic temperature gradient. Its theoretical foundation is still under debate, but practical applications for analytics in biology show considerable potential. Here we measured the thermophoresis of highly diluted single stranded DNA using an all-optical capillary approach. Temperature gradients were created locally by an infrared laser. The thermal depletion of oligonucleotides of between 5 and 50 bases in length were investigated by fluorescence at various salt concentrations. To a good approximation, the previously tested capacitor model describes thermophoresis: the Soret coefficient linearly depends on the Debye length and is proportional to the DNA length to the power of 0.35, dictated by the conformation-based size scaling of the diffusion coefficient. The results form the basis for quantitative DNA analytics using thermophoresis.
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.
Publisher: American Chemical Society (ACS)
Date: 27-09-2023
Publisher: American Chemical Society (ACS)
Date: 17-06-2013
DOI: 10.1021/NN4013059
Abstract: The photoinduced formation of silver nanoprisms from smaller silver seed particles in the presence of citrate anions is a classic ex le of a photomorphic reaction. In this case, light is used as a convenient tool to dynamically manipulate the shape of metal nanoparticles. To date, very little is known about the prevailing reaction mechanism of this type of photoreaction. Here we provide a detailed study of the shape transformation dynamics as a function of a range of different process parameters, such as photon energy and photon flux. For the first time, we provide direct evidence that the photochemical synthesis of silver nanoprisms from spherical seed nanoparticles proceeds via a light-activated two-dimensional coalescence mechanism. On the other hand, we could show that Ostwald ripening becomes the dominant reaction mechanism when larger silver nanoprisms are grown from photochemically synthesized smaller nanoprisms. This two-step reaction proceeds significantly faster and yields more uniform, sharper nanoprisms than the classical one-step photodevelopment process from seeds. The ability to dynamically control nanoparticle shapes and properties with light opens up novel synthesis avenues but also, more importantly, allows one to conceive new applications that exploit the nonstatic character of these nanoparticles and the ability to control and adjust their properties at will in a highly dynamic fashion.
Publisher: Springer Science and Business Media LLC
Date: 22-07-2020
DOI: 10.1038/S41598-020-68848-9
Abstract: We employed Mendelian randomization (MR) to evaluate the causal relationship between leukocyte telomere length (LTL) and amyotrophic lateral sclerosis (ALS) with summary statistics from genome-wide association studies ( n = ~ 38,000 for LTL and ~ 81,000 for ALS in the European population n = ~ 23,000 for LTL and ~ 4,100 for ALS in the Asian population). We further evaluated mediation roles of lipids in the pathway from LTL to ALS. The odds ratio per standard deviation decrease of LTL on ALS was 1.10 (95% CI 0.93–1.31, p = 0.274) in the European population and 0.75 (95% CI 0.53–1.07, p = 0.116) in the Asian population. This null association was also detected between LTL and frontotemporal dementia in the European population. However, we found that an indirect effect of LTL on ALS might be mediated by low density lipoprotein (LDL) or total cholesterol (TC) in the European population. These results were robust against extensive sensitivity analyses. Overall, our MR study did not support the direct causal association between LTL and the ALS risk in neither population, but provided suggestive evidence for the mediation role of LDL or TC on the influence of LTL and ALS in the European population.
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.
Publisher: OSA
Date: 2017
Publisher: American Chemical Society (ACS)
Date: 05-11-2020
Publisher: AIP Publishing
Date: 08-2020
DOI: 10.1063/5.0013473
Abstract: Diamond containing the nitrogen-vacancy (NV) center is emerging as a significant sensing platform. However, most NV sensors require microscopes to collect the fluorescence signals and therefore are limited to laboratory settings. By embedding micron-scale diamond particles at an annular interface within the cross section of a silicate glass fiber, we demonstrate a robust fiber material capable of sensing magnetic fields. Luminescence spectroscopy and electron spin resonance characterization reveal that the optical properties of NV centers in the diamond microcrystals are well preserved throughout the fiber drawing process. The hybrid fiber presents a low propagation loss of ∼4.0 dB/m in the NV emission spectral window, permitting remote monitoring of the optically detected magnetic resonance signals. We demonstrate NV-spin magnetic resonance readout through 50 cm of fiber. This study paves a way for the scalable fabrication of fiber-based diamond sensors for field-deployable quantum metrology applications.
Publisher: American Chemical Society (ACS)
Date: 03-11-2017
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.
Publisher: Springer Science and Business Media LLC
Date: 03-11-2020
DOI: 10.1038/S41467-020-19275-X
Abstract: The capabilities of imaging technologies, fluorescent sensors, and optogenetics tools for cell biology are advancing. In parallel, cellular reprogramming and organoid engineering are expanding the use of human neuronal models in vitro. This creates an increasing need for tissue culture conditions better adapted to live-cell imaging. Here, we identify multiple caveats of traditional media when used for live imaging and functional assays on neuronal cultures (i.e., suboptimal fluorescence signals, phototoxicity, and unphysiological neuronal activity). To overcome these issues, we develop a neuromedium called BrainPhys™ Imaging (BPI) in which we optimize the concentrations of fluorescent and phototoxic compounds. BPI is based on the formulation of the original BrainPhys medium. We benchmark available neuronal media and show that BPI enhances fluorescence signals, reduces phototoxicity and optimally supports the electrical and synaptic activity of neurons in culture. We also show the superior capacity of BPI for optogenetics and calcium imaging of human neurons. Altogether, our study shows that BPI improves the quality of a wide range of fluorescence imaging applications with live neurons in vitro while supporting optimal neuronal viability and function.
Publisher: Wiley
Date: 10-03-2010
Publisher: Wiley
Date: 07-2019
Abstract: Recent work in biomolecule-metal-organic framework (MOF) composites has proven to be an effective strategy for the protection of proteins. However, for other biomacromolecules such as nucleic acids, the encapsulation into nano MOFs and the related characterizations are in their infancy. Herein, encapsulation of a complete gene-set in zeolitic imidazolate framework-8 (ZIF-8) MOFs and cellular expression of the gene delivered by the nano MOF composites are reported. Using a green fluorescent protein (GFP) plasmid (plGFP) as a proof-of-concept genetic macromolecule, successful transfection of mammalian cancer cells with plGFP for up to 4 days is shown. Cell transfection assays and soft X-ray cryo-tomography (cryo-SXT) demonstrate the feasibility of DNA@MOF biocomposites as intracellular gene delivery vehicles. Expression occurs over relatively prolonged time points where the cargo nucleic acid is released gradually in order to maintain sustained expression.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9NR02593F
Abstract: Rapid thermal annealing of electron irradiated nanoscale type Ib diamond particles facilitates formation of various nitrogen-related fluorescent color centers, providing either red, yellow, green, or blue fluorescence for downstream multiplex imaging applications.
Publisher: SPIE
Date: 30-12-2019
DOI: 10.1117/12.2539124
Publisher: SPIE
Date: 30-12-2019
DOI: 10.1117/12.2541225
Publisher: Informa UK Limited
Date: 12-2019
Publisher: Springer Science and Business Media LLC
Date: 23-06-2022
DOI: 10.1007/S10815-022-02555-4
Abstract: A current focus of the IVF field is non-invasive imaging of the embryo to quantify developmental potential. Such approaches use varying wavelengths to gain maximum biological information. The impact of irradiating the developing embryo with discrete wavelengths of light is not fully understood. Here, we assess the impact of a range of wavelengths on the developing embryo. Murine preimplantation embryos were exposed daily to wavelengths within the blue, green, yellow, and red spectral bands and compared to an unexposed control group. Development to blastocyst, DNA damage, and cell number/allocation to blastocyst cell lineages were assessed. For the longer wavelengths (yellow and red), pregnancy/fetal outcomes and the abundance of intracellular lipid were investigated. Significantly fewer embryos developed to the blastocyst stage when exposed to the yellow wavelength. Elevated DNA damage was observed within embryos exposed to blue, green, or red wavelengths. There was no effect on blastocyst cell number/lineage allocation for all wavelengths except red, where there was a significant decrease in total cell number. Pregnancy rate was significantly reduced when embryos were irradiated with the red wavelength. Weight at weaning was significantly higher when embryos were exposed to yellow or red wavelengths. Lipid abundance was significantly elevated following exposure to the yellow wavelength. Our results demonstrate that the impact of light is wavelength-specific, with longer wavelengths also impacting the embryo. We also show that effects are energy-dependent. This data shows that damage is multifaceted and developmental rate alone may not fully reflect the impact of light exposure.
Publisher: Wiley
Date: 17-07-2021
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.
Publisher: American Chemical Society (ACS)
Date: 24-12-2019
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
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.
Publisher: American Chemical Society (ACS)
Date: 05-07-2023
Publisher: American Chemical Society (ACS)
Date: 17-06-2013
DOI: 10.1021/NN401775E
Abstract: Gold nanoparticles and nearby fluorophores interact via electromagnetic coupling upon light excitation. We determine the distance and wavelength dependence of this coupling theoretically and experimentally via steady-state and time-resolved fluorescence spectroscopy. For the first time, the fluorescence quenching of four different dye molecules, which absorb light at different wavelengths across the visible spectrum and into the near-infrared, is studied using a rigid silica shell as a spacer. A comprehensive experimental determination of the distance dependence from complete quenching to no coupling is carried out by a systematic variation of the silica shell thickness. Electrodynamic theory predicts the observed quenching quantitatively in terms of energy transfer from the molecular emitter to the gold nanoparticle. The plasmonic field enhancement in the vicinity of the 13 nm gold nanoparticles is calculated as a function of distance and excitation wavelength and is included in all calculations. Relative radiative and energy transfer rates are determined experimentally and are in good agreement with calculated rates. We demonstrate and quantify the severe effect of dye-dye interactions on the fluorescence properties of dyes attached to the surface of a silica nanoparticle in control experiments. This allows us to determine the experimental conditions, under which dye-dye interactions do not affect the experimental results.
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.
Publisher: American Chemical Society (ACS)
Date: 13-10-2020
Publisher: American Chemical Society (ACS)
Date: 11-09-2020
Publisher: The Optical Society
Date: 23-03-2017
DOI: 10.1364/OL.42.001297
Publisher: American Chemical Society (ACS)
Date: 23-05-2022
Abstract: Nanodiamonds are at the heart of a plethora of emerging applications in areas ranging from nanocomposites and tribology to nanomedicine and quantum sensing. The development of alternative synthesis methods, a better understanding, and the availability of ultrasmall nanodiamonds of less than 3 nm size with a precisely engineered composition, including the particle surface and atomic defects in the diamond crystal lattice, would mark a leap forward for many existing and future applications. Yet today, we are unable to accurately control nanodiamond composition at the atomic scale, nor can we reliably create and isolate particles in this size range. In this perspective, we discuss recent advances, challenges, and opportunities in the synthesis, characterization, and application of ultrasmall nanodiamonds. We particularly focus on the advantages of bottom-up synthesis of these particles and critically assess the physicochemical properties of ultrasmall nanodiamonds, which significantly differ from those of larger particles and bulk diamond.
Publisher: IOP Publishing
Date: 08-07-2019
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.
Publisher: Wiley
Date: 10-2020
Publisher: SPIE
Date: 30-12-2019
DOI: 10.1117/12.2539890
Publisher: Springer Science and Business Media LLC
Date: 26-10-2018
DOI: 10.1038/S41467-018-06789-8
Abstract: Energetic ions represent an important tool for the creation of controlled structural defects in solid nanomaterials. However, the current preparative irradiation techniques in accelerators show significant limitations in scaling-up, because only very thin layers of nanoparticles can be efficiently and homogeneously irradiated. Here, we show an easily scalable method for rapid irradiation of nanomaterials by light ions formed homogeneously in situ by a nuclear reaction. The target nanoparticles are embedded in B 2 O 3 and placed in a neutron flux. Neutrons captured by 10 B generate an isotropic flux of energetic α particles and 7 Li + ions that uniformly irradiates the surrounding nanoparticles. We produced 70 g of fluorescent nanodiamonds in an approximately 30-minute irradiation session, as well as fluorescent silicon carbide nanoparticles. Our method thus increased current preparative yields by a factor of 10 2 –10 3 . We envision that our technique will increase the production of ion-irradiated nanoparticles, facilitating their use in various applications.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9NR08984E
Abstract: We use direct imaging and dynamic light scattering to reveal the previously unknown dynamic self-assembly of detonation nanodiamond dispersions in water which have been purified without additional surface modification.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1NR04847C
Abstract: Detonation nanodiamonds self-assemble into fractal-like structures in aqueous suspensions. Our work shows that the size and shape of these structures strongly depend on the particle concentration but not on the ionic strength of the suspension.
Publisher: Springer Science and Business Media LLC
Date: 27-01-2017
DOI: 10.1038/NCOMMS14000
Publisher: Elsevier BV
Date: 03-2023
Publisher: Elsevier BV
Date: 02-2021
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.
Publisher: Wiley
Date: 23-06-2016
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C6NR07834F
Abstract: Bright and photostable fluorescence from nitrogen-vacancy (NV) centers is demonstrated in unprocessed detonation nanodiamond particle aggregates. The optical properties of these particles is analyzed using confocal fluorescence microscopy and spectroscopy, time resolved fluorescence decay measurements, and optically detected magnetic resonance experiments. Two particle populations with distinct optical properties are identified and compared to high-pressure high-temperature (HPHT) fluorescent nanodiamonds. We find that the brightness of one detonation nanodiamond particle population is on the same order as that of highly processed fluorescent 100 nm HPHT nanodiamonds. Our results may open the path to a simple and up-scalable route for the production of fluorescent NV nanodiamonds for use in bioimaging applications.
Publisher: American Chemical Society (ACS)
Date: 29-03-2023
Publisher: American Chemical Society (ACS)
Date: 05-10-2016
DOI: 10.1021/ACS.JPCLETT.6B01884
Abstract: Gold nanoparticles located at a metal oxide/hole conductor interface generate photocurrents upon visible light illumination. We demonstrate that the quantum efficiency of this process depends on the nanoparticle size. Gold nanoparticles (5 nm) show a maximum absorbed photon-to-electron conversion efficiency (APCE) of 13.3%. For increasing particle sizes, the average APCE decreases to 3.3% for the largest particles (40 nm) investigated. Three possible causes for this efficiency change are discussed.
Publisher: Wiley
Date: 11-10-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2SD00006G
Abstract: Methods for the endogenous detection of nitroxyl (azanone HNO), the reduced and protonated derivative of nitric oxide (NO), are required to define its cardiovascular function and its key role in chronic pain.
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.
Publisher: Elsevier BV
Date: 02-2019
Publisher: Wiley
Date: 28-01-2019
Publisher: Springer Science and Business Media LLC
Date: 14-09-2019
Publisher: IEEE
Date: 06-2019
Publisher: Wiley
Date: 22-10-2013
Publisher: American Chemical Society (ACS)
Date: 14-06-2019
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
Publisher: American Chemical Society (ACS)
Date: 04-04-2022
Abstract: Indium nitride (InN) has been of significant interest for creating and studying two-dimensional electron gases (2DEG). Herein we demonstrate the formation of 2DEGs in ultrathin doped and undoped 2D InN nanosheets featuring high carrier mobilities at room temperature. The synthesis is carried out via a two-step liquid metal-based printing method followed by a microwave plasma-enhanced nitridation reaction. Ultrathin InN nanosheets with a thickness of ∼2 ± 0.2 nm were isolated over large areas with lateral dimensions exceeding centimeter scale. Room temperature Hall effect measurements reveal carrier mobilities of ∼216 and ∼148 cm
Publisher: Wiley
Date: 13-12-2019
Abstract: A new spiropyran-based stimuli-responsive delivery system is fabricated. It encapsulates and then releases an extraneous compound in response to elevated levels of Zn
Publisher: American Chemical Society (ACS)
Date: 27-09-2017
Publisher: IOP Publishing
Date: 09-05-2018
Abstract: Detonation nanodiamonds (DNDs) have emerged as promising candidates for a variety of biomedical applications, thanks to different physicochemical and biological properties, such as small size and reactive surfaces. In this study, we propose carbon dot decorated single digit (4-5 nm diameter) primary particles of detonation nanodiamond as promising fluorescent probes. Due to their intrinsic fluorescence originating from tiny (1-2 atomic layer thickness) carbonaceous structures on their surfaces, they exhibit brightness suitable for in vitro imaging. Moreover, this material offers a unique, cost effective alternative to sub-10 nm nanodiamonds containing fluorescent nitrogen-vacancy color centers, which have not yet been produced at large scale. In this paper, carbon dot decorated nanodiamonds are characterized by several analytical techniques. In addition, the efficient cellular uptake and fluorescence of these particles are observed in vitro on MDA-MD-231 breast cancer cells by means of confocal imaging. Finally, the in vivo biocompatibility of carbon dot decorated nanodiamonds is demonstrated in zebrafish during the development. Our results indicate the potential of single-digit detonation nanodiamonds as biocompatible fluorescent probes. This unique material will find application in correlative light and electron microscopy, where small sized NDs can be attached to antibodies to act as a suitable dual marker for intracellular correlative microscopy of biomolecules.
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.
Location: Australia
Start Date: 11-2022
End Date: 11-2025
Amount: $400,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2023
End Date: 12-2023
Amount: $852,787.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2020
End Date: 06-2022
Amount: $600,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 08-2020
End Date: 12-2024
Amount: $424,198.00
Funder: Australian Research Council
View Funded Activity