30 November 2016:
CNBP Research Fellows, Associate Professor Guozhen Liu (pictured), Dr Lindsay Parker and Dr Sabrina Heng have undertaken talks at the School of Biomedical Sciences at the University of Melbourne as part of a Biosensor Symposium, Wednesday 30th November, 2016.
Talks were as follows:
Guozhen Liu – Biophotonic Tools for Cytokine Sensing: From an on-cell surface ELISA to a spatial ELISA device.
Lindsay Parker – Biosensors and glycoproteins: linking nanoscience to neuroscience.
Sabrina Heng – Reversible Sensing with a Flip of the Switch.
The symposium shone a spotlight on multidisciplinary research into developing, applying and using biosensors for biomedical sciences.
23 August 2016
CNBP researchers from the University of Adelaide, Michelle Zhang and Sabrina Heng, have undertaken a school outreach session at St. Ignatius College, Adelaide, August 23, 2016.
The scientists spoke to two groups of children in an early-learning program about the science of light and the use of light in medicine. Several hands-on activities were also then run for the children to demonstrate that science can be fun as well as educational.
- the use of UV-sensitive beads for making into a bracelet that was then worn for several outdoor activities
- sunscreen applied to the beads to teach how sunscreen protects against sun-burn
- the use of spectroscopes that can diffract room-light into a series of colourful bands at differing wavelengths (the students were asked to draw what they saw)
- a simple kit that converted youtube videos to holograms
- and CNBP colouring-in sheets that demonstrate life at the nanoscale
Positive feedback from the teachers at St. Ignatius College and also the parents of the children that attended the session was received over the course of a very fulfilling day!
10 August 2016:
Researchers from the CNBP have published a paper representing the first major study of the stability and compatibility of the major classes of photochromic compounds within the microstructured optical fibre (MOF) environment.
In developing light-responsive surfaces, investigators face several challenges, not only in achieving high photostationary states and fully reversible switching, but also in fluorescence properties and fatigue resistance upon continuous exposure to high intensity light. However, information on the latter two are often lacking as studies on photochromic compounds are often focused on photoswitching, or absorbance and colour changes. To address this gap in literature, the fluorescence and photostability of four major types of photochromic molecules (azobenzene, spiropyran, indolyfulgide and diarylalkene) when dissolved in DMSO, or acetonitrile, or adsorbed to a MOF silica surface were investigated.
Journal: Sensors and Actuators B: Chemical.
Publication title: A Comparative Study of the Fluorescence and Photostability of Common Photoswitches in Microstructured Optical Fibre.
Authors: Daniel B. Stubing (pictured top left), Sabrina Heng, Tanya M. Monro and Andrew D. Abell.
Abstract: The fluorescence spectra and photostability under 532 nm laser excitation of four different common photoswitches (an azobenzene, spiropyran, indolylfulgide, and a diarylperfluorocyclopentene) were investigated in a silica microstructured optical fibre. An example of each photoswitch was examined in solution and physically adsorbed to the silica fibre surface. This comparison was made to define fluorescence behaviour in these two states and to determine which photoswitch has the best performance in this light intense microenvironment. The azobenzene and the spiropyran switches demonstrated the strongest fluorescence response and the least degradation of the fluorescence signal.
The paper is available online.
13 May 2016:
CNBP researchers have created nanoscale biosensors that are capable of sensing Zn2+ ions in biological samples. Such sensors have potential application in disease diagnosis and study, as well as in environmental sensing. The study was published in the journal ACS Applied Materials and Interfaces, May 13th, 2016.
Publication title: Microstructured Optical Fiber-based Biosensors: Reversible and Nanoliter-Scale Measurement of Zinc Ions.
Authors: Sabrina Heng (pictured), Christopher A. McDevitt, Roman Kostecki, Jacqueline R. Morey, Bart A. Eijkelkamp, Heike Ebendorff-Heidepriem, Tanya M. Monro, and Andrew D. Abell.
Sensing platforms that allow rapid and efficient detection of metal ions would have applications in disease diagnosis and study, as well as environmental sensing. Here, we report the first microstructured optical fiber-based biosensor for the reversible and nanoliter-scale measurement of metal ions. Specifically, a photoswitchable spiropyran Zn2+ sensor is incorporated within the microenvironment of a liposome attached to microstructured optical fibers (exposed-core and suspended-core microstructured optical fibers). Both fiber-based platforms retains high selectivity of ion binding associated with a small molecule sensor, while also allowing nanoliter volume sampling and on/off switching. We have demonstrated that multiple measurements can be made on a single sample without the need to change the sensor. The ability of the new sensing platform to sense Zn2+ in pleural lavage and nasopharynx of mice was compared to that of established ion sensing methodologies such as inductively coupled plasma mass spectrometry (ICP-MS) and a commercially available fluorophore (Fluozin-3), where the optical-fiber-based sensor provides a significant advantage in that it allows the use of nanoliter (nL) sampling when compared to ICP-MS (mL) and FluoZin-3 (μL). This work paves the way to a generic approach for developing surface-based ion sensors using a range of sensor molecules, which can be attached to a surface without the need for its chemical modification and presents an opportunity for the development of new and highly specific ion sensors for real time sensing applications.
The paper is available online.
1 May 2016:
CNBP researchers Dr Hannah Brown, Dr Sabrina Heng and Dr Erik Schartner (pictured) presented invited talks to a range of researchers and clinicians at the ‘Scientists in Reproductive Technology (SIRT)’ conference in Adelaide on the 1st of May, 2016.
Explored in their talks were differing ways in which upcoming Centre research might find use within the embryology labs of the future – this tying into the meeting theme “From basic research to clinical practice: How to revolutionise IVF practice.”
Talk titles from the CNBP researchers were as follows:
- Hannah: Haemoglobin: Exciting and unexpected roles in fertility.
- Sabrina: Developing light-driven regenerable chemical tools for biological applications.
- Erik: Developing optical fibre probes for biosensing.
Further information on Scientists in Reproductive Technology (SIRT), a sub-group representing the scientific membership of The Fertility Society of Australia, can be found online.
19 April 2016:
CNBP was happy to host the next generation of young scientists at today’s ‘STEMSEL Photonics’ session at the University of Adelaide node.
STEMSEL clubs, standing for ‘Science, Technology, Engineering, Maths and Social Enterprise Learning’ are an arm of the STEMSEL Foundation which is a not for profit organisation that aims to teach every child how to use electronics.
Over twenty Year 3 to Year 9 students were in attendance at this session, with CNBP researchers Roman Kostecki (a physics focus) and Sabrina Heng (a chemistry focus) helping lead the discussion and activities.
Concepts such as photons, light interaction with matter, Fermat’s principle, emission, absorption, lasers, fibre optics and organic chemistry, were all described and demonstrated.
Both researchers enjoyed the afternoon, showing the kids that science, technology and photonics can be awesomely interesting, as well as really good fun!
21 March 2016:
CNBP researchers Daniel Stubing, Sabrina Heng and Andrew Abell recently published a full paper in the journal ‘Organic and Biomolecular Chemistry’.
The published work presents three new spiropyran photoswitchable sensors and compares their sensitivity to different monovalent metal ions to develop a new reversible lithium ion sensor. These sensing molecules are now able to be further used to create optical devices for the sensing of biological lithium ions, which could help further understanding and treatment of neurological diseases such as manic-depressive illness.
Title: Crowned spiropyran fluoroionophores with a carboxyl moiety for the selective detection of lithium ions
Authors: D. B. Stubing, S. Heng and A. D. Abell
Abstract: The absorbance and fluorescence spectra of carboxylated spiropyrans containing methyl-1-aza-12-crown-4, methyl-1-aza-15-crown-5, methyl-1-aza-18-crown-6 moieties are compared. Characteristic changes in spectra after addition of the alkali metal salts of Li+, Na+, K+ and Cs+ were observed. Chromism induced by the binding of the metal cations was observed as an increase in absorbance and fluorescence. Of these metal cations, the Li+ ion produced the largest change in all three spiropyran systems. Reversible photoswitching of the spiropyran-metal complexes was observed on irradiation with alternating 352 nm UV and white light. This results in reversible fluorescence based sensing of lithium ions with potential for use in a biological sensor device.
The paper is accessible online.
10 March 2016:
Dr Sabrina Heng, CNBP researcher has undertaken a further school visit to Lockleys Primary School in Adelaide as a part of her involvement in the Scientists and Mathematicians in Schools (SMiS) outreach program.
SMiS is a national volunteer program bringing real science, mathematics and ICT into the classroom through ongoing flexible partnerships between teachers and scientists, mathematicians and ICT professionals.
Sabrina has been involved with SMiS since 2010 and working with Lockelys Primary School since mid 2014. In her most recent visit to the school, the Year 5/6 science students learned about the concepts of solubility and saturation through a series of simple experiments that Sabrina had designed. Working in groups, the students were taught to ‘think like a scientist’ i.e. ask the question (e.g. how many scoops of NaCl does it take to saturate X amount of water?), perform the experiment and to then come up with a conclusion.
Said Sabrina, “My trips to Lockleys are always rewarding and I look forward to my next visit where we will be performing experiments around the topic of ‘Light’.”
3 March 2016:
Dr Sabrina Heng, CNBP researcher has undertaken a school visit to Lockleys Primary School in Adelaide as a part of the ‘Scientists in Schools’ outreach program.
Sabrina has been part of the Scientists in Schools program since 2011 and from last year has been attached to Lockleys, and more specifically to a year 5/6 class of approximately 15-16 students.
As part of the program, Sabrina is given a copy of the school curriculum for the year and works in coordination with the class teacher to design simple experiments for the students to work on.
Says Sabrina, “Last week was the first meeting of the school year so I talked about my work at CNBP and life as a scientist. I also sat down with the the teacher to plan out upcoming experiments. The students will be learning about solubility and saturation in the coming weeks so I plan to design an experiment around that, that they can work on.”
Concluded Sabrina, “I try to help students relate to what they learn in text books to real-world experimentation. It seems like the kids always look forward to my visit and I have a really good relationship with the school!”
7 February 2016:
CNBP researchers Peipei Jia (pictured), Philipp Reineck, Ivan Maksymov, Sabrina Heng and Daniel Stubing all attended the International Conference on Nanoscience and Nanotechnology (ICONN), in Canberra (7-11 February 2016).
Peipei Jia, CNBP Research Fellow, presented an invited talk on the topic ‘Large-area Gold Nanomembrane by Template Transfer with a Soluble Polymer’.
Philipp presented a poster on the nanoparticle comparison project, Daniel presented a poster titled “Reversible Ion Sensing With a Flip of a Switch”, while Ivan gave an oral talk on “Photoacoustic nanoantennae for intravascular imaging.”
Sabrina’s poster presentation was titled, “Microstructured Optical Fibers and Photoswitches: Light-Driven Sensors for Metal Ions.”
The event covered the areas of nanostructure growth, synthesis, fabrication, characterization, device design, theory, modeling, testing, applications, commercialisation, and health and safety aspects of nanotechnology.
Further information on the conference is available online.