Talk 1: 

Linda Mitchell: A versatile fluorescent sensing system to monitor platinum-based chemotherapies

Biography: Linda completed her BSc (Advanced Science) at the University of Sydney including a Year-in-Industry at the National Measurement Institute. She completed her Honours year in Chemistry in 2016 under the supervision on Associate Professor Elizabeth New and Professor Trevor Hambley. In 2017 she received a Westpac Future Leaders Scholarship to conduct her PhD under the supervision of Liz New. During her PhD studies, Linda has been an active member of the chemistry community. She has been a safety warden for two years and in 2018 she was a member of the Equity, Diversity and Inclusion committee. In 2019 she was a member of the Safety committee, the Researcher Liaison Committee and the Student President of the Sydney University Chemical Society, which included chairing the 2019 Postgraduate Symposium. She is an active member of her research group, and loves organising group activities and supervising less experienced students with their research.

Abstract: Platinum-based drugs are one of the longest and most widely-used classes of cancer chemotherapeutics. Whilst effective at treating cancer, the sideeffects accompanying platinum-based chemotherapy are unpredictable and often severe enough to necessitate dose-reductions, reducing their efficacy. Directly monitoring platinum levels in patients during treatment, rather than relying on side-effects to determine dose-reductions, could enable more effective treatment plans and perhaps more successful clinical outcomes. Array-based fluorescent sensing is an emerging technique that employs multiple sensing elements to detect analytes in complex systems, such as the blood stream. To address the need for a versatile and robust sensing system, we have created a fluorescent array for platinum-based sensing. The six-sensor array is able to discriminate between eight different platinum complexes, can effectively identify different concentrations of cisplatin and oxaliplatin spiked in human plasma and has demonstrated concentration-dependent discrimination in a cohort of 27 cancer patients treated with platinum-based chemotherapy.

Christopher Vega Sánchez: Drag reduction and boundary slip at liquid-liquid interfaces

Biography: Christopher Vega received the B.Eng. degree in Electromechanical Engineering from the Costa Rica Institute of Technology (ITCR). In 2011, he was awarded a DAAD scholarship to attend a M.Sc. in Microsystems Engineering from the University of Freiburg, Germany. In 2014, he joined the Department of Electromechanical Engineering at ITCR, where he worked on the design of low-cost microfluidics and simulation. He moved to Sydney in 2018 and commenced his Ph.D. candidature working on the study of boundary conditions for small scale fluid flows and slippage on nanostructured surfaces.

Abstract: After a long history of discussions and debates, thanks to the advances in the technology for studying fluid flows at small scales, we recently proved the no-slip boundary condition in fluid dynamics to be wrong. Fluids can slip on solid walls; the fluid tangential velocity at the wall is finite but for most cases it is also tiny in magnitude. Although the discovery of this partial slip condition at the boundary has little implication in the study of largescale systems, this finding is of great scientific relevance because it advances the completeness of the theory that we use to describe the nature of fluids. Here, we address a more complex problem: the study of the boundary condition at fluid-fluid interfaces between immiscible fluids. Our twophase flow domain of interest consists of an oil-infused surface which is exposed to laminar flow of water-like fluids. We combine, for the first time, highly accurate measurements of microscopic variables, such as pressure and flow rate taken from a microfluidic setup, and nanometric measurements of the interface using atomic force microscopy to study the true behavior of the liquid-liquid interface. We have found that under the widely accepted assumption of no-slip at the interface, our experimental observations disagree with the current theory. We propose a shear dependent process of gas nucleation at the interface as an additional mechanism to explain the large slippage observed in our system. These findings are of great significance for the study of two-phase flow microsystems and provide a deep insight to the nature and behavior of these interfaces.