6 February 2018:
Tiny 5 nm detonation nanodiamonds glow in different colors and their fluorescence is pH dependent, reports a new paper by CNBP scientists published today in the Nature journal Scientific Reports.
Lead author of the paper Dr Philipp Reineck from RMIT University (Former CNBP Research Fellow and current CNBP Associate Investigator) notes that the research is particulalry exciting as the fluorescence lifetime of the detonation nanodiamonds makes fluorescence lifetime imaging (FLIM) for bioimaging applications feasible.
Journal: Scientific Reports.
Publication title: Visible to near-IR fluorescence from single-digit detonation nanodiamonds: excitation wavelength and pH dependence.
Authors: Philipp Reineck, Desmond W. M. Lau, Emma R. Wilson, Nicholas Nunn, Olga A. Shenderova & Brant C. Gibson.
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.
11 November 2017:
Fantastic TV talents (and CNBP researchers) Prof Brant Gibson and Dr Philipp Reineck from RMIT University featured on SCOPE TV for kids, 11th November 2017.
Check them out as they discuss the use of diamond nanoparticles in biophotonics to help shed light on cells and the living body!
31 October 2017:
Surface chemistry is vital for nanodiamond fluorescence, reports a new paper published by CNBP researchers (lead author Dr Philipp Reineck pictured). The paper was published in the journal ‘ACS Nano’ and is available online.
Journal: ACS Nano.
Publication title: Effect of Surface Chemistry on the Fluorescence of Detonation Nanodiamonds.
Authors: Philipp Reineck, Desmond W. M. Lau, Emma R. Wilson, Kate Fox, Matthew R. Field, Cholaphan Deeleepojananan, Vadym N. Mochalin, and Brant C. Gibson.
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.
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.
17 May 2017:
CNBP’s Dr Philipp Reineck has given a talk at the Aimé-Cotton Laboratory (LAC), Paris, which he is currently visiting as a guest researcher.
The laboratory is a joint research unit of the National Center for Scientific Research (CNRS), the University of Paris-Sud and the Ecole Normale Supérieure de Cachan.
Philipp’s talk consisted of an overview of CNBP science and more specifically, focused on Centre projects across the nano-diamond sensing and bio-imaging space.
10 May 2017:
Dr Philipp Reineck, CNBP Research Fellow, has given an invited talk at the ENM Nanoparticle meeting in San Sebastian in Spain, 10 May 2017.
His talk was titled, ‘Near-IR fluorescent nanomaterials for bioimaging and sensing applications.’ Dr Reineck also chaired a workshop/session on nanoparticles for optical bioimaging.
Further information on the conference can be found online.
1 May 2017:
Dr Philipp Reineck, CNBP Researcher at RMIT University has won best poster award at the 5th International Conference on Biophotonics (ICOB 2017), 30 April – 1 May 2017, Fremantle, Western Australia.
The poster reported on recent advances in the development and use of near-infrared fluorescent nanomaterials for biomedical imaging and sensing applications.
Dr Reineck was originally invited to give a short oral presentation about his poster, which was then selected as a ‘hot poster’ before the conference commenced. It then won ‘best poster’ resulting in a cash prize of $600 AUD.
During his short talk at ICOB, Philipp also discussed the potential of NIR fluorescent materials for wearables – for example, a watch that interrogates particles in bloodstream via near infrared light, to determine glucose levels.
Information about the ICOB conference is available online.
18 January 2017:
Researchers at CNBP’s RMIT University node were busy doing light-based demonstrations on Wednesday Jan 18th, as part of the ‘RMIT University Experience Day’ program, whereby students from years 10, 11 and 12 get to engage in hands-on workshops and explore life on campus while experiencing the differing aspects of University discipline areas.
As part of the ‘experience’ activity, over seventy high school students (predominantly in Year 10) visited the CNBP researchers in their physics laboratories. While there, students were given an overview of biophotonic science as well as laboratory research, and shown the exciting things that can be done with light including 3D scanning, fluorescence microscopy and more.
Below – CNBP researcher Philipp Reineck talks and demonstrates photonics to students.
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.