23 August 2017:
Researchers from CNBP’s RMIT University node (lead author Ashleigh Heffernan), have published a paper demonstrating a directed self-assembly method to position nanodiamonds on glass. The method, allowing for the statistical quantification of fluorescent nanoparticles provides a step towards fabrication of hybrid photonic devices for applications from quantum cryptography to sensing.
The paper is accessible online.
Journal: Scientific Reports.
Publication title: Nanodiamond arrays on glass for quantification and fluorescence characterisation.
Authors: Ashleigh H. Heffernan, Andrew D. Greentree & Brant C. Gibson.
Abstract: Quantifying the variation in emission properties of fluorescent nanodiamonds is important for developing their wide-ranging applicability. Directed self-assembly techniques show promise for positioning nanodiamonds precisely enabling such quantification. Here we show an approach for depositing nanodiamonds in pre-determined arrays which are used to gather statistical information about fluorescent lifetimes. The arrays were created via a layer of photoresist patterned with grids of apertures using electron beam lithography and then drop-cast with nanodiamonds. Electron microscopy revealed a 90% average deposition yield across 3,376 populated array sites, with an average of 20 nanodiamonds per site. Confocal microscopy, optimised for nitrogen vacancy fluorescence collection, revealed a broad distribution of fluorescent lifetimes in agreement with literature. This method for statistically quantifying fluorescent nanoparticles provides a step towards fabrication of hybrid photonic devices for applications from quantum cryptography to sensing.
3 July 2017:
Researchers from CNBP’s RMIT University node (lead author CNBP PhD student Marco Capelli pictured), have had a paper published in the journal ‘Nanoscale’.
The researchers report an enhancement of the nitrogen-vacancy (NV) quantum yield by up to 7% in bulk diamond caused by an external magnetic field.
The paper is accessible online.
Publication title: Magnetic field-induced enhancement of the nitrogen-vacancy fluorescence quantum yield .
Authors: M. Capelli, P. Reineck, D. W. M. Lau, A. Orth, J. Jeske, M. W. Doherty, T. Ohshima, A. D. Greentree and B. C. Gibson.
Abstract: The nitrogen-vacancy (NV) centre in diamond is a unique optical defect that is used in many applications today and methods to enhance its fluorescence brightness are highly sought after. We observed experimentally an enhancement of the NV quantum yield by up to 7% in bulk diamond caused by an external magnetic field relative to the field-free case. This observation is rationalised phenomenologically in terms of a magnetic field dependence of the NV excited state triplet-to-singlet transition rate. The theoretical model is in good qualitative agreement with the experimental results at low excitation intensities. Our results significantly contribute to our fundamental understanding of the photophysical properties of the NV defect in diamond.
1 June 2017:
CNBP was well represented at the 11th International Conference on New Diamond and Nano Carbons, held in Cairns, Australia, 28th May – June 1, 2017.
CNBP Chief Investigator A/Prof Brant Gibson was Co-chair of the conference (pictured) with CNBP researcher Dr Philipp Reineck a contributing speaker, presenting on ‘Bright and photostable nitrogen‐vacancy fluorescence from unprocessed detonation nanodiamonds’.
Also providing a contributing talk was CNBP’s Dr Lindsay Parker, ‘Applications of fluorescent nanodiamonds in cellular molecular tracing.’
Additionally, CNBP’s Andrew Greentree, Ivan Maksymov, Daniel Drumm, Ashleigh Heffernan, Marco Capelli, Nicole Cordina and Emma Wilson gave poster presentations and Brooke Bacon and Desmond Lau provided administrative and technical support respectively.
The conference spanned research topics from fundamental physical and chemical concepts to applied technologically driven applications with carbon based materials. This including single crystal diamond, nanodiamonds, carbon nanotubes, graphene and other carbon nanostructures.
5 December 2016:
A new publication from CNBP researchers (lead author Philipp Reineck pictured) demonstrates bright and photostable fluorescence from nitrogen-vacancy centers in unprocessed nanodiamond particle aggregates. The work has just been reported in the journal ‘Nanoscale’ and is accessible online.
Title: Bright and photostable nitrogen-vacancy fluorescence from unprocessed detonation nanodiamond.
Authors: P. Reineck, M. Capelli, D. W. M. Lau, J. Jeske, M. R. Field, T. Ohshim, A. D. Greentree and B. C. Gibson.
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.
28 October 2016:
CNBP researchers Philipp Reineck (pictured left) and A/Prof Brant Gibson explore recent advances in the development and use of near-infrared fluorescent nanomaterials for biomedical imaging and sensing applications in this just released review paper.
Journal: Advanced Optical Materials
Title: Near-Infrared Fluorescent Nanomaterials for Bioimaging and Sensing
Authors: Philipp Reineck and Brant Cameron Gibson
Abstract: A great challenge in noninvasive biomedical imaging is the acquisition of
images inside a biological system at the cellular level. Common modalities used today
such as magnetic resonance or computed tomography imaging have the advantage that
any part of a living organism can be imaged at any depth, but are limited to millimeter
resolution and can usually not be employed e.g., for surgical guidance. Optical imaging
techniques offer resolution on the 100 nanometer scale, but are limited by the strong
attenuation of visible light by biological matter and are traditionally used to image on the
surface. Near-infrared light in the “biological windows” can penetrate much deeper into
biological samples, rendering fluorescence-based imaging a viable alternative. In the past
two decades, many fluorescent nanomaterials have been developed to operate in the near
infrared, yet only few materials emitting above 1000 nm exist and none are approved for
clinical use. This review describes recent advances in the development and use of nearinfrared fluorescent nanomaterials for biomedical imaging and sensing applications. The physical and chemical properties as well as the bioconjugation and application of materials such as organic fluorophores, semiconductor quantum dots, carbon-based materials, rare earth materials, and polymer particles are discussed.
The paper is accessible online.
4 January 2016:
CNBP’s A/Prof. Brant Gibson (CNBP CI) and Dr. Desmond Lau (CNBP Technical Officer) featured as co-authors in a recently published paper in the journal ‘Nano Letters’.
The paper exploited the recent discovery of the piezoelectricity in odd-numbered layers of two-dimensional molybdenum disulfide (MoS2), to show the possibility of reversibly tuning the photoluminescence of single and odd-numbered multilayered MoS2 using high frequency sound wave coupling.
As such, the work reveals several key fundamentals governing acousto-optic properties of odd-layered MoS2 that can be implemented in future optical and electronic systems.
Additional information can be found in the Journal ‘Nano Letters’ online.
20 October 2015:
CNBP’s RMIT node reached out to the public today, hosting a panel discussion on nanoscale technology as a part of Melbourne Knowledge Week.
‘Up Close and Revealed: Life at the Nanoscale’ was the theme of the event with a focus on nanoscale optical sensors, quantum technology and next generation computational devices.
Panel speakers consisted of CNBP’s RMIT node leader A/Prof Brant Gibson, CNBP Advisory Board member Prof Goran Roos, Prof Calum Drummond from RMIT and CNBP industry partner Mr Jian Shen from Olympus Australia.
Following the entertaining and informative panel dialogue, members of the public were provided with tours of CNBP’s new research laboratories, and provided with further information on CNBP’s current research activities.
Melbourne Knowledge Week showcases the city’s broad range of innovative projects, institutions and ideas with over 50 separate events taking place from the 19th to 25th October 2015.
16 October 2015:
CNBP CI Brant Gibson talked with radio station 3CR about an event – ‘Up Close and Revealed: Life at the Nanoscale’, a public panel discussion that took place at CNBP’s RMIT node for Melbourne Knowledge Week.
You can click through to the 19:50 minute mark (when Brant’s interview begins) or listen to the entire 30 minute show.
6 October 2015:
Brant Gibson, CNBP node leader at RMIT, visited Macquarie University for two days on October 6/7 and gave an invited colloquium in the Physics department and also had a number of meetings with CNBP personnel.
The well attended colloquium was titled, “Nanodiamond: BioPhotonic and Hybrid-Photonic Applications,” and examined ways in which nano-diamonds are ideal for developing fluorescent bioimaging nanoprobes. Details of the research activities at the RMIT node of the ARC Centre of Excellence for Nanoscale BioPhotonics were also discussed.
24 August 2015:
Nanoscale biosensing in reproductive medicine was the theme of a CNBP symposium at the Annual Scientific Meeting of the Endocrine Society of Australia and the Society for Reproductive Biology for 2015.
CNBP speakers included Prof. Mark Hutchinson, Prof. Ewa Goldys and A/Prof Brant Gibson who presented the concepts/applications of their CNBP work, followed by presentations specifically related to reproduction by Dr Erik Schartner, Mr Malcolm Purdy and Dr Sabrina Heng.
Title talks were as follows:
Mark Hutchinson: New windows into the body.
Ewa Goldys: Through the looking glass: what can we see in the early embryo when we look carefully enough.
Brant Gibson: Nanodiamond for BioPhotonic and Hybrid-Photonic applications.
Sabrina Heng: Microstructured Optical Fibers and Photoswitches: Light-Driven Sensors for
Metal Ions in Biology.
Erik Schartner: Development of optical fibre probes for biosensing applications.
Malcolm S Purdey: A Non-invasive Sensor for Hydrogen Peroxide and pH.
Further information on the meeting is available online.