Prof. Paolo Actis will talk on 'Macromolecular crowding in single entity electrochemistry'

Paolo Actis
Bragg Centre for Materials Research, University of Leeds, Leeds, UK

Abstract
The fundamental unit of life, the cell, is a microscopic chemical reactor where thousands of processes happen simultaneously to bring about biological function in a highly crowded environment. To study these cellular processes, the manipulation of cells by controlled delivery of biological macromolecules is indispensable. Whilst transfection of cells with nucleic acids is routine, the delivery of proteins can be challenging. Moreover, current methods do not enable the absolute quantification of the number of molecules delivered into cells and has no (or little) temporal control.
I will present a nanoinjection platform to enable quantitative delivery, with single molecule resolution, of nucleic acids, proteins, and protein aggregates into living cells. Nanoinjection uses nanopipettes, to inject macromolecules into cells via the application of a small voltage (<1V). This delivery platform has 4 key features: (i) the nanopipette’s small size relative to a cell means that it is minimally invasive and nanoinjection has negligible effects on cell viability (ii) spatial control of nanoinjection enables site specific delivery of molecules into cells e.g. in the cytoplasm or nucleus,(iii) temporal control of nanoinjection as delivery is triggered only when a defined voltage is applied to the nanopipette and (iv) the nanopipette can detect individual macromolecules as they pass through the pore thus enabling quantitative delivery into cells with single-molecule resolution.
We have observed a remarkable increase in the amplitude and dwell time of the single molecule events when molecules are nanoinjected into a cell. We will present experiments, finite-element modelling, and MD simulations to propose a mechanism describing the signal enhancement and we will discuss the potential implementation of the nanoinjection process to detect crowding in living cells.

Biography
I am an Associate Professor in Bionanotechnology and my research involves the development of nanoprobes for single-cell analysis and manipulation with single molecule resolution.
I am working with biologists and physicians to understand the deepest difference between healthy cells and diseased cells. After graduating in 2008 with a PhD from the Grenoble Institute of Technology (FR), I spent 4 years in California working on my tan at NASA Ames (US) and UC Santa Cruz (US) before crossing the pond again to lose my tan at Imperial College London (UK). I then spent two years at Bio Nano Consulting as a Consultant & Project Manager.
I love gardening and cooking (I make the best Lasagna this side of the Channel) and I used to play beach volleyball, surf and practice Krav Maga (with very mediocre results). I am massive Juventus fan!

Dr Minkyung Kang will talk on 'Probing Electrochemical Activity in Complex Electromaterials'

Minkyung Kang
School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia

Abstract
The field of Single entity electrochemistry (SEE) is an exciting and rapidly evolving area of research that focuses on characterizing the electrochemical properties of simple units within more complex systems. These units can range in size from the nanoscale to the microscale and can include molecules, particles, or surface features such as step sites, terraces, or regions with specific surface chemistry. One powerful tool that has been developed for investigating the electrochemical properties of these units is scanning electrochemical cell microscopy (SECCM). SECCM is a versatile and robust electrochemical imaging technique that allows for the direct correlation of structure and activity at the nanoscale. By using a mobile droplet cell to confine the unit of interest in a small volume, SECCM can visualize and investigate the electrochemical activity at interfaces with high spatiotemporal resolution. This has made it an indispensable tool in the toolbox of researchers studying SEE. In this seminar, various applications of SECCM in SEE will be featured, including electrocatalysis, corrosion science, and materials science. It will be explored how SECCM can be used to investigate the electrochemical properties of electrode materials ranging from particles and two-dimensional materials to metal alloys and complex polycrystalline substrates. By highlighting the wide range of materials that can be studied using SECCM, this seminar will demonstrate the versatility and power of this technique for investigating SEE.
 
Biography
Dr Minkyung Kang completed her PhD at the University of Warwick (UK) in 2018. She worked as a research fellow at Imperial College London (2017-2018) and the University of Warwick (2018-2020; Leverhulme Early Career Fellowship) before joining Deakin University in 2020. This year, she has joined the School of Chemistry at the University of Sydney as an ARC DECRA fellow/lecturer. Her research focus centres around electrochemistry, and she is currently working on developing a unique electrochemical imaging technology to aid in the rational design of efficient energy conversion/storage materials.