All posts by Tony Crawshaw

New aptasensor able to detect intracellular IFN-γ

8 January 2018:

A new research paper, resulting from a partnership between CNBP and Jilin University has been published, reporting on the development of a new aptasensor which is able to detect ultrasmall concentrations of intracellular IFN-γ. This simple and highly sensitive sensor is able to be used for real-time bio-imaging, providing  a universal sensing platform for monitoring a spectrum of molecules secreted by cells.

Journal: ACS Sensors.

Publication title: “Turn-on” Fluorescent Aptasensor Based on AIEgen Labeling for the Localization of IFN-γ in Live Cells.

Author: Ke Ma, Fengli Zhang, Nima Sayyadi, Wenjie Chen, Ayad G. Anwer, Andrew Care, Bin Xu , Wenjing Tian, Ewa M. Goldys and Guozhen Liu.

Abstract: We report an aggregation-induced emission fluorogen (AIEgen)-based turn-on fluorescent aptasensor able to detect the ultrasmall concentration of intracellular IFN-γ. The aptasensor consists of an IFN-γ aptamer labeled with a fluorogen with a typical aggregation-induced emission (AIE) characteristic, which shows strong red emission only in the presence of IFN-γ. The aptasensor is able to effectively monitor intracellular IFN-γ secretion with the lowest detection limit of 2 pg mL-1, and it is capable of localizing IFN-γ in live cells during secretion, with excellent cellular permeability and biocompatibility as well as low cytotoxicity. This probe is able to localize the intracellular IFN-γ at a low concentration <10 pg mL-1, and it is successfully used for real-time bioimaging. This simple and highly sensitive sensor may enable the exploration of cytokine pathways and their dynamic secretion process in the cellular environment. It provides a universal sensing platform for monitoring a spectrum of molecules secreted by cells.

Multi-LED light source for hyperspectral imaging

15 December 2017:

A multi-LED light source has been investigated by CNBP researchers for use in hyperspectral imaging. The research featured in the journal ‘Optics Express’  with the lead author on the paper, PhD student Kashif Islam, based at Macquarie University.

Journal: Optics Express.

Publication titleMulti-LED light source for hyperspectral imaging.

Author: Kashif Islam, Martin Ploschner, and Ewa M. Goldys.

Abstract: We investigate a novel light source design for efficient collection of UV light from multiple LEDs. The design is based on a truncated cone with a large circular lid incorporating LEDs on one side, and a small circular exit aperture (diameter of 9 mm) on the other side. The exit aperture size allows a simple coupling with secondary optics of a microscope for hyperspectral imaging that requires a wide spectrum of frequencies of illuminating light. The light collection efficiency was optimized with respect to cone length and diameter of the LED lid. In all simulations, we use a highly UV-reflecting aluminum coating on the inner surfaces of the cone. The influence of the LED positions on the cone efficiency is determined by varying the LED distance from the central axis as well as the interLED distance. We found the maximum efficiency of the cone is realized for LEDs positioned at the center, and the shorter is the inter-LED distance, the better is the performance of the light source.

Nanoscale biophotonics for the ‘other’ brain

12 December 2017:

CNBP Director Prof Mark Hutchinson, The University of Adelaide has published a new review and commentary on the future of sensor development in the exciting new world of neuroimmunoscience!

Journal: Microelectronic Engineering.

Publication titleThe importance of knowing you are sick: Nanoscale biophotonics for the ‘other’ brain.

Author: Mark R. Hutchinson.

Abstract: A great new frontier in biomedical science has recently been discovered that requires the attention of technologists from diverse backgrounds to equip scientists with the tools needed to explore this great uncharted area. This new expanding domain is the exploration of the neuroimmune cells of the central nervous system, and their real-time function and contributions to the health and disease of the brain and spinal cord. Glia, once thought of as mere structural supports for the brain, are now appreciated to actively contribute to brain function. However, the true complexity of this system is still hidden from close examination, owing to a range of technological and methodological limitations. Here, some of these opportunities and challenges are outlined to expose the micro and nanoengineering community to this dynamic area of research, and to encourage innovation and technology application in the research of the “other brain”.

Science meets art

11 December 2017:

Science met art as researchers from CNBP and the Institute for Photonics and Advanced Sensing (IPAS) visited the ‘Quantum Colour: Capturing The Movement Of Light’ exhibition at Adelaide’s JamFactory and got a back-stage tour with artist and Creative Director of JamFactory Glass Studio, Karen Cunningham.

The exhibition, melding science with traditional glass blowing techniques features Cunningham’s works and sees her explore nanoparticles as a primary constituent of how light may be subverted or augmented in hand-made glass art. Her glass works were inspired by meetings and interactions with CNBP and IPAS researchers over the course of the year.

CNBP Director, Prof Hutchinson believes that scientists and artists are more alike than different and that the two have a lot that they are able to share. “When science and art collide it means scientists and artists can share their inspirations, get creative and produce fantastic and innovative outcomes.”

Further information on the exhibition, Karen Cunningham and her engagement with CNBP science can be read online in an article in the Adelaide Review.

Below – one of the glass works being exhibited at JamFactory.

ARC CEO visits CNBP laboratories

10 December 2017:

Professor Sue Thomas, Chief Executive Officer (CEO) of the Australian Research Council (ARC) has visited CNBP laboratories at the University of Adelaide and gained  first-hand experience of the exciting biophotonics science taking place there.

Shown around a number of laboratory spaces by CNBP Director Prof Mark Hutchinson, Prof Thomas spent time examining the glass fabrication facilities used by the Centre as well as exploring more fully, the exciting ‘smart needle brain probe’ work headed-up by Prof Robert McLaughlin.

Other CNBP related activity included discussion with Centre researchers of industry relevant translational work currently being undertaken in the food and wine quality assessment area.

Prof Mark Hutchinson said of the visit , “It was fantastic to share with Prof Thomas how the breadth of our ARC funded CNBP fundamental science program is translating to industry projects and how this is leading to new leveraged funding and employment opportunities for our talented CNBP scientists.”

Below – ARC CEO Prof Sue Thomas is given a hands-on demonstration of a ‘smart needle’ probe for the brain by CNBP’s Prof Robert McLaughlin.

Annual CNBP conference jam-packed!

4 December 2017:

The CNBP research community (Chief investigators, Associate Investigators, researchers, students and members of the International Science Committee) came together for the Fourth Annual CNBP Conference, Tue 28th November to Fri 1st December 2017, in what was a jam-packed schedule of science.

Activities at the Conference included ‘quick speed’ data blitz presentations; key note speeches from CNBP researchers and international guests including from Professor Kishan Dholakia, Professor Kelly Nash and Professor Volker Deckert; science speed dating sessions; poster sessions and team building activities including the infamous grand spaghetti tower challenge which proved to be far more demanding than expected!

The largest Conference to date, the event allowed for an amazing amount of fantastic data to be shared, with collaborations continuing to be built and developed, and new ideas being generated and explored by enthusiastic and engaged team members from across all nodes and partner institutions.

Additional Conference highlights included a professional development session by Dr Peter Grace investigating “The how and why of networking for Scientists” and then a discussion on the importance of tools and social platforms such as LinkedIn, and then pointers on how best to approach senior researchers and potential collaborators at events and other Conferences.

Finally, there was a ‘reflective session’ which provided an opportunity to reflect on science discussions and to then actively plan for the next 12 months of CNBP related activity.

Below – Photos from what was an extremely rewarding Conference!

Copper oxide nanocubes good for bioimaging

Nafisa Zohora4 December 2017:

New CNBP research determines that copper oxide nanocubes are suitable for long-term bioimaging experiments. Lead author on the paper – CNBP PhD student Zafisa Zohora (RMIT University).

Journal: Scientific Reports.

Publication titleFluorescence brightness and photostability of individual copper (I) oxide nanocubes.

Authors: Nafisa Zohora, Ahmad Esmaielzadeh Kandjani, Antony Orth, Hannah M. Brown, Mark R. Hutchinson & Brant C. Gibson.

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 individual particles. In this manuscript, we present a method to study the intrinsic optical characteristics of individual copper (I) oxide (Cu2O) nanocubes. When excited at 520 nm using only 11 µW excitation power (1.7 W/cm2), individual 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, Cu2O nanocubes are attractive candidates for long-term fluorescent bioimaging applications.

New hybrid sensor developed

21 November 2017:

A new hybrid sensor combining an organic fluorescent probe bound to a nanodiamond has been developed by CNBP researchers (lead author Dr Malcolm Purdey pictured). Able to detect hydrogen peroxide, the sensor is non-toxic and is also highly photostable.

Journal: Scientific Reports.

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

Authors: Malcolm S. Purdey, Patrick K. Capon, Benjamin J. Pullen, Philipp Reineck, Nisha Schwarz, Peter J. Psaltis, Stephen J. Nicholls, Brant C. Gibson & Andrew D. Abell.

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.

New unmixing method to detect and measure fluorophores

17 November 2017:

A new CNBP paper “Statistically strong label-free quantitative identification of native fluorophores in a biological sample,” by Saabah B. Mahbub (first author pictured), Martin Plöschner, Martin E. Gosnell, Ayad G. Anwer and Ewa M. Goldys has just been published in Scientific Reports and is available online.

This work addresses a genuine shortage of methods for real-time continuous monitoring of biochemistry of cells and tissues, especially live cells. Saabah Mahbub and team developed an automated and unbiased unmixing methodology to non-invasively detect the presence and spatial distributions of endogenous fluorophores in retina cells. The method was validated on artificial images, where the addition of a varying known level of noise has allowed to quantify the accuracy of spectral unmixing.

With its capability for high throughput, automation and embedded compatibility with statistical analysis this work will contribute to improved quantification and objectivity in biomedical research.

Microfluidic droplet extraction

16 November 2017:

CNBP and Macquarie University PhD candidate Shilun Feng is first author on a new paper exploring a ‘membrane-on-a-chip’ device. The technology has the potential to form an integral part of a new type of microneedle that would be able to transport tiny and precise amounts of fluid/medication within the body.

Journal: Micromachines.

Publication titleMicrofluidic Droplet Extraction by Hydrophilic Membrane.

Authors: Shilun Feng, Micheal N. Nguyen, and David W. Inglis.

Abstract: Droplet-based microfluidics are capable of transporting very small amounts of fluid over long distances. This characteristic may be applied to conventional fluid delivery using needles if droplets can be reliably expelled from a microfluidic channel. In this paper, we demonstrate a system for the extraction of water droplets from an oil-phase in a polymer microfluidic device. A hydrophilic membrane with a strong preference for water over oil is integrated into a droplet microfluidic system and observed to allow the passage of the transported aqueous phase droplets while blocking the continuous phase. The oil breakthrough pressure of the membrane was observed to be 250 ± 20 kPa, a much greater pressure than anywhere within the microfluidic channel, thereby eliminating the possibility that oil will leak from the microchannel, a critical parameter if droplet transport is to be used in needle-based drug delivery.