Friday, 17 November 11:00am – 12:00pm

This seminar will be delivered in Chemistry Lecture Theatre 2

Speaker: Dr Carol Hua, University of Melbourne

Host: Dr Kaye Kang

Title: Shining a Light on Chemical Sensors and Stimuli Responsive Materials

Abstract: The development of real-time, highly sensitive chemical sensors for the detection of very low analyte concentrations is of importance for monitoring harmful chemicals in the environment. Strategies to enhance the sensitivity and accuracy of sensors can be achieved through the incorporation of lanthanoid ions enabling the detection of low analyte concentrations, and through using a stimuli-switchable motif. By switching between different states of the chemical sensor, enhanced accuracy of detection in complex matrices can be detected.

Metal-Organic Frameworks (MOFs) are crystalline materials containing inorganic nodes bridged by linkers. The high tunability of MOFs enable the systematic modification of pore chemistry and size. Tailored pore environments can be designed, making these materials well-suited to act as chemical sensors and stimuli responsive materials.¹ Reports of lanthanoid MOFs containing a stimuli responsive motif are still relatively scarce in the literature despite the potential they have for enhanced chemical sensing and the development of switchable materials.

This presentation will detail our latest results in the design of chiral sensors and stimuli responsive materials. The chiral sensing properties of two BINOL-based Zn MOF systems will be highlighted², with varying degrees of fluorescence quenching. The mechanism of fluorescence quenching and guest position within the framework as elucidated through time resolved fluorescence and computational calculations will be discussed. The switchable and chemical sensing properties of an isostructural series of lanthanoid MOFs containing a redox-active viologen ligand (Figure 1) will also be presented. The reversible one electron reduction of the viologen from its dication to its radical cation state upon exposure to a light and pressure stimulus are elucidated from photoirradiation and high-pressure experiments on the MX1 beamline at the Australian Synchrotron.

Bio: Dr Carol Hua is currently a Senior Lecturer in the School of Chemistry. Carol received her BSc(Hons) from the University of New South Wales (2011) and her PhD from the University of Sydney (2016) for which she was awarded the 2016 RACI Cornforth Medal for an outstanding PhD thesis in chemistry. She undertook postdoctoral researcher positions at the University of Limerick, Ireland and Northwestern University, USA supported by the Endeavour and American-Australian Fellowships. In 2018, Carol moved back to Australia to start her independent research career as a McKenzie Fellow at the University of Melbourne before becoming a Lecturer at Deakin University in 2021. Carol returned to the University of Melbourne in February 2023 in a continuing position as a Senior Lecturer. Current research interests include the development of metal-organic frameworks as chemical sensors and stimuli responsive materials.