Georgina Sylvia was trained as a chemist, but teaming up with biologists and physicists is all in a day’s work. At the ARC Centre of Excellence for Nanoscale BioPhotonics, Dr Sylvia uses light to understand minuscule biological changes that can have a big impact on human health. Continue reading
CNBP researchers Dr Georgina Sylvia and Dr Erin Smith (in conjunction with Children’s University Adelaide) have taken their love of science to the public, demonstrating fun-filled experiments to budding young scientists at a ‘pop-up’ event titled ‘The Magic and Wonder of Science’. The event took place as part of the biennial ‘Dream Big Children’s Festival’, held in South Australia, May-June, 2019.
Attendees at the ‘pop-up’ outreach event saw science working in practice as well as real-life applications of differing scientific elements.
“We demonstrated numerous experiments to our audience including creating ‘Elephant’s Toothpaste’. This is a foamy substance caused by the rapid decomposition of hydrogen peroxide,” says Georgina.
“Other experiments included a demonstration of atmospheric pressure with a jar of water, as well as the use of liquid nitrogen to freeze an everyday egg in a fry-pan. We wanted to inspire our young audience and to open their minds to the everyday science that exists all around them,” she says.
“Our show aimed to be a blend of entertainment and education with plenty of humor and laughs as well.”
Below – Erin and Georgina putting on their scientific show!
A new publication from CNBP researchers (lead author Georgina Sylvia pictured), presents the rational design and photophysical characterisation of spiropyran-based chemosensors for magnesium.
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+.
A new rationally designed, photostable, red-emitting calcium sensor with enhanced fluorescence intensity has been presented by CNBP researchers in a paper published in the journal ‘Tetrahedron’. Lead author on the paper is CNBP’s Georgina Sylvia (pictured – University of Adelaide).
Authors: Georgina M. Sylvia, Sabrina Heng, Akash Bachhuka, Heike Ebendorff-Heidepriem,
Andrew D. Abell.
A rationally designed, pyrene-spiropyran hybrid Ca2+ sensor (Py-1) with enhanced fluorescence intensity compared to a standalone spiropyran analogue is presented. Importantly, Py-1 retains the characteristic red emission profile of the spiropyran, while fibre-based photostability studies show the sensor is stable after multiple cycles of photoswitching, without any sign of photodegradation. Such properties are of real advantage for cell-based sensing applications. An interesting observation is that, Py-1 presents with two excitation options; direct green excitation (532 nm) of the photoswitch for a red emission, and UV excitation (344 nm) of the component pyrene, which gives rise to distinct blue and red emissions. This proof-of-concept hybrid sensing system presents as a more general approach to brighter spiropyran-based sensors.