Monthly Archives: April 2018

A novel, high sensitivity Sagnac-interferometer biosensor

30 April 2018:

A new publication featuring CNBP co-authors (Dr Stephen Warren-Smith pictured left and Prof Heike Ebendorff-Heidepriem) reports on the design and implementation of a novel, high sensitivity Sagnac-interferometer biosensor based on an exposed core microstructured optical fiber (ECF).

Journal: Sensors and Actuators B: Chemical.

Publication title: High-sensitivity Sagnac-interferometer biosensor based on exposed core microstructured optical fiber.

Authors: Xuegang Li, Linh V. Nguyen, Yong Zhao, Heike Ebendorff-Heidepriem, Stephen C. Warren-Smith.

Abstract: A novel, high sensitivity Sagnac-interferometer biosensor based on exposed core microstructured optical fiber (ECF) has been designed and implemented in this paper. The exposed core fiber has noncircular symmetry and thus exhibits birefringence and can form a sensing element within a Sagnac loop interferometer. The exposed-core fiber design provides direct access to the evanescent field, allowing the measurement of bulk refractive index (RI) with a sensitivity of up to −3137 nm/RIU while maintaining the fiber’s robustness. The sensor can also detect the localized refractive index changes at the fiber core’s surface as the result of a biological binding event. We demonstrate the use of this sensor for label-free sensing of biological molecules by immobilizing biotin onto the fiber core as the probe to capture the target molecule streptavidin.

Fellowship supports ongoing study into chronic pain

26 April 2018:

The Centre for Nanoscale BioPhotonics (CNBP), an Australian Research Council Centre of Excellence is pleased to announce that Logan Jenkins, a researcher at Vanderbilt University, USA, is the successful recipient of the CNBP-American Australian Association (AAA) Fellowship for 2018.

The Fellowship, coordinated by the AAA and funded by the CNBP, provides US$30,000 to support an American graduate student, PhD or early career Postdoctoral Fellow who wishes to conduct collaborative research at a CNBP research node in Australia.

In this instance, it will allow Logan Jenkins, who specialises in Biophotonics, to take forward research that will explore how light can be used to control neuronal activity, as well as to examine how such techniques potentially impact the body’s neuroimmune system.

This area of study will directly align with CNBP’s activity in the chronic pain space says Mark Hutchinson, CNBP Director and Professor at the University of Adelaide.

“Within the CNBP we examine the working neuroimmune interface at a cellular level and in particular, how the brain’s immune-like cells are linked to chronic pain, a condition that affects millions of people world-wide,” Professor Hutchinson says.

“We will work closely with Logan to see how his light-based neuronal control mechanisms, and neuroimmune related study, links to our own advanced research in this area.”

Jenkins is looking forward to meeting the CNBP research team in Australia.

“This Fellowship will give me the opportunity to work closely with a prestigious Centre of Excellence and I look forward to conducting some excellent and impactful research. I also hope to build scientific friendships that will lead to ongoing collaborations and discovery,” he says.

Prof Mark Hutchinson welcomed the Fellowship appointment.

“The CNBP seeks to conduct international cutting-edge research in Biophotonics. In order to do this we need to have the best people in the world collaborating with us. This includes rising stars like Logan who comes to us from the Vanderbilt Biophotonics Center, an outstanding organisation which leads the world in ‘neuronal control by light’ investigation.”

“Logan will be based primarily at the University of Adelaide during this Fellowship and will also spend time at CNBP’s other research nodes as he explores his research program in the Centre,” says Professor Hutchinson.

Further information on the United States to Australia Scholarships can be found online at the American Australian Association website. The AAA seeks to build closer USA to Australia ties.

The research is also being supported by the Air Force Office of Scientific Research (AFOSR) and enabled through access to the Australian National Fabrication Facility (ANFF).

Below – Logan Jenkins.

New CNBP review paper on SERS

23 April 2018:

CNBP researchers have  published a new review paper on surface enhanced Raman scattering (SERS), reporting on recent developments and applications, and in particular examining SERS nanotags in biosensing and bioimaging, describing case studies in which differing types of biomarkers have been investigated. Lead author on the paper was Wei Zhang from Macquarie University.

Journal: Journal of Analysis and Testing.

Publication title: SERS Nanotags and Their Applications in Biosensing and Bioimaging.

Authors: Wei Zhang, Lianmei Jiang, James A. Piper, Yuling Wang.

Abstract: Owing to the unique advantages of surface enhanced Raman scattering (SERS) in high sensitivity, specifcity, multiplexing capability and photostability, it has been widely used in many applications, among which SERS biosensing and bioimaging are the focus in recent years. The successful applications of SERS for non-invasive biomarker detection and bioimaging under in vitro, in vivo and ex vivo conditions, ofer signifcant clinical  information to improve diagnostic and prognostic outcomes. This review provides recent developments and applications of SERS, in particular SERS nanotags in biosensing
and bioimaging, describing case studies in which diferent types of biomarkers have been investigated, as well as outlining future challenges that need to be addressed before SERS sees both pathological and clinical use.

Centre outreach encourages a career in science

18 April 2018:

Two fantastic sessions of outreach in two days by CNBP researcher Dr Annemarie Nadort saw 100 Year 11 and Year 12 students learn about biophotonics, blood cells and the skills required to create medical devices that benefit society.

The sessions took place at Macquarie University and were part of a highly successful initiative aimed at encouraging students to undertake higher education learning and potentially develop a career in science.

During the outreach sessions, Dr Annemarie Nadort provided the students with a brief overview of light-based imaging and how it could be best applied to examine blood inside the body. Students were then presented with a real-life case-study on the development of a clinical microcirculation imager. A hands-on demonstration of the device then took place, followed by an interactive group discussion on how the device could be potentially improved with future development. Students were then left with the message that there were many opportunities open to them across the scientific and technology disciplines,  and that they should study in those areas that they were most enthusiastic about.

“I was extremely impressed as to how engaged these students were,” said Dr Annemarie Nadort. “They provided some great answers during the group discussion stage of the session and had really thought through issues and potential solutions. I could see the keenness for science and technology in the room and hopefully my sessions added to that keenness and passion for science. I’d love to see some of these students become the researchers of the future, developing their own fantastic new medical devices over the years and decades to come.”

Below: Dr Annemarie Nadort communicating the wonders of science to high school students and explaining what it takes to become a successful academic research scientist.

Advanced sensor to unlock the secrets of the brain

17 April 2018:

CNBP researchers have announced the development of a state-of-the-art sensor that can for the first time detect signalling molecules, called cytokines, which operate in the living brain. Cytokines in the brain are secreted by glia cells that make up nearly 90% of all brain cells. Cytokines play a central role in controlling mood and cognition and may also contribute to a number of mental health disorders.

“What we’ve developed is the first sensor capable of monitoring the release of these cytokines in the brain,” says lead researcher Kaixin Zhang, a PhD candidate at the ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP) at Macquarie University.

“Critically, there is mounting evidence that these glial-released cytokines play a central role in regulating a range of brain functions. In particular they are responsible for affecting mood, cognition and behaviour.”

“Our innovative new sensor has the potential to increase our knowledge not only of how the brain works, but may be able to shed light on conditions such as depression, stress, anxiety and even schizophrenia,” he says.

The sensor consists of a modified optical fibre which has had its surface treated with a capture protein. The protein reacts to the presence of cytokine molecules and is capable of monitoring local cytokine release in discrete and targeted parts of the brain.

Professor Ewa Goldys, CNBP Deputy Director, and a senior researcher on the project, notes that brain functionality is an extremely complex area where scientific knowledge is still limited.

“Our research in understanding cytokine secretion, neural circuits and how these two work together is essential to improving our understanding of the brain, in health and disease. Our sensor has opened a new window to the brain, but we still have far more to discover,” she says.

“The key benefit of our new sensor is that it enables the detection of cytokine release precisely as it happens, in living, naturally behaving animals, which is the key step on this discovery journey. To date, suitable tools have not been available to do this as the living brain is an incredibly difficult part of the body to access, and these cytokines are very difficult to measure.”

Published in the leading scientific journal ‘Brain, Behavior, and Immunity’, the cytokine sensor research was undertaken by an international team of scientists at the ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), Macquarie University, University of Colorado Boulder, Central China Normal University and The University of Adelaide.

“This is a really fantastic example of the work which we do at the CNBP, which is all about creating state-of-the-art sensing tools that can measure the inner workings of the living organism,” says Prof Goldys.

“It may be early days in this research but it will be fascinating to see where this cytokine detection takes us. It may prove to be a pivotal point in the understanding, and eventual diagnostic and clinical treatment, of a whole range of health conditions.”

A novel platform for in vivo detection of cytokine release within discrete brain regions.

AUTHORS: Kaixin Zhang, Michael V. Baratta, Guozhen Liu, Matthew G. Frank, Nathan R. Leslie, Linda R. Watkins, Steven F. Maier, Mark R. Hutchinson, Ewa M. Goldys.

Below – CNBP PhD Candidate – Kaixin Zhang.

Sensing magnesium

17 April 2018:

A new publication from CNBP researchers (lead author Georgina Sylvia pictured), presents the rational design and photophysical characterisation of spiropyran-based chemosensors for magnesium.

Journal: Chemosensors.

Publication title: A Rationally Designed, Spiropyran-Based Chemosensor for Magnesium.

Authors: Georgina M. Sylvia, Adrian M. Mak, Sabrina Heng, Akash Bachhuka, Heike Ebendorff-Heidepriem, and Andrew D. Abell.

Abstract: Magnesium ions (Mg2+) play an important role in mammalian cell function; however, relatively little is known about the mechanisms of Mg2+ regulation in disease states. An advance in this field would come from the development of selective, reversible fluorescent chemosensors, capable of repeated measurements. To this end, the rational design and fluorescence-based photophysical characterisation of two spiropyran-based chemosensors for Mg2+ are presented. The most promising analogue, chemosensor 1, exhibits 2-fold fluorescence enhancement factor and 3-fold higher binding affinity for Mg2+ (Kd 6.0 µM) over Ca2+ (Kd 18.7 µM). Incorporation of spiropyran-based sensors into optical fibre sensing platforms has been shown to yield significant signal-to-background changes with minimal sample volumes, a real advance in biological sensing that enables measurement on subcellular-scale samples. In order to demonstrate chemosensor compatibility within the light intense microenvironment of an optical fibre, photoswitching and photostability of 1 within a suspended core optical fibre (SCF) was subsequently explored, revealing reversible Mg2+ binding with improved photostability compared to the non-photoswitchable Rhodamine B fluorophore. The spiropyran-based chemosensors reported here highlight untapped opportunities for a new class of photoswitchable Mg2+ probe and present a first step in the development of a light-controlled, reversible dip-sensor for Mg2+.

Successful BioNetwork 2018 symposium

13 April 2018:

The BioNetwork 2018 symposium titled ‘Killing it in Science’ was held Friday, 13th April at Macquarie University with significant CNBP involvement at the event.

The aim of the symposium was to foster interactions across the Macquarie University biosciences researcher community encompassing the Science & Engineering and Medicine & Health Sciences Faculties.

A unique career-building panel session was held in the morning of the symposium and a scientific session was held in the afternoon to create a platform for interdisciplinary research collaborations to commence novel or strengthen existing projects.

CNBP Associate Investigators Dr Alfonso Garcia-Bennett (Macquarie University) and Dr Varun Sreenivasan (University of New South Wales) were both invited speakers at the event speaking to their careers in academia, providing tips for advancement as well as outlining challenges that they had faced.

For the science session, CNBP students Mina Ghanimi Fard and Sameera Iqbal (pictured top left) jointly presented on the brain and the targeting and measuring of central nervous system sugar receptors. Other CNBP students also took part with Piotr Wargocki, Kashif Islam, Minakshi Das and Rachit Bansal presenting their CNBP releated science during the morning and lunch-time poster sessions.

CNBP AI’s Annemarie Nadort and Nima Sayyadi were both key members of the symposium organising committee.

“We had a fantastic engaged crowd of over 150 attendees and a wide range of presenters covering careers in academia, research-industry collaboration, innovative bio-research activity and much much more,” said Annemarie Nadort.

“There was so much positive feedback from participants on the day and we’ve kick-started a great many conversations and discussions which will hopefully build new research relationships and lead to even more innovative science taking place.”

Below – Organiser Annemarie Nadort observing the successful symposium panel discussion from the wings.

Fibre-needle probe for imaging and sensing in deep tissue

6 April 2018:

A world-first tiny fibre-optic probe that can simultaneously measure temperature and sense deep inside the body has been reported by CNBP/IPAS researchers. According to lead author of the research, Dr Jiawen Li at the University of Adelaide, the probe may help researchers find better treatments to prevent drug-induced overheating of the brain, and potentially refine thermal treatment for cancers. Read the media release or click on the publication title below!

Journal: Optics Letters.

Publication title: Miniaturized single-fiber-based needle probe for combined imaging and sensing in deep tissue.

Authors: Jiawen Li, Erik Schartner, Stefan Musolino, Bryden C. Quirk, Rodney W. Kirk, Heike Ebendorff-Heidepriem, and Robert A. McLaughlin.

Abstract: The ability to visualize structure while simultaneously measuring chemical or physical properties of a biological tissue has the potential to improve our understanding of complex biological processes. We report the first miniaturized single-fiber-based imaging+sensing probe capable of simultaneous optical coherence tomography (OCT) imaging and temperature sensing. An OCT lens is fabricated at the distal end of a double-clad fiber, including a thin layer of rare-earth-doped tellurite glass to enable temperature measurements. The high refractive index of the tellurite glass enables a common-path interferometer configuration for OCT, allowing easy exchange of probes for biomedical applications. The simultaneous imaging+sensing capability is demonstrated on rat brains.

Below – Dr Jiawen Li.