The ambition of SENTINEL is to equip the next generation of electrochemists with the skills needed to tackle the most important societal challenges. Our fellows have made substantial progress with the development of novel electrochemical techniques for the characterisation of nanomaterials. For example, we developed and applied a new method for the characterisation of the electrocatalytic activity of nanoparticles and discovered how the activity depends on the local physio-chemical properties of the nanoparticle. In parallel the team in Paris has developed an innovative optical method for studying the generation of nanobubbles on the surface of Pt nanoparticles. The team based in Aarhus developed an innovative approach to measure the surface charge of DNA-based nanostructures and they are further developing the methodology to enable the charge mapping at the surface of living cells.
We have also performed a range of training activities for the fellows, including a leadership lecture from a former Olympic medallist.
We have significantly expanded and developed microscopy methods for nanoelectrochemistry, in which the team has particular expertise, including:
• The advancement of electrical and electrochemical capabilities of atomic force microscopy (AFM) techniques for the electrical and electrochemical characterization of single proteins and protein membranes;
• The development of new scanned electrochemical probes, including multi-channel probes for the multifunctional analysis of single cells and single nanoparticles;
• High-speed methods, taking advantage of recent developments from our industrial partner, Keysight, in GHz-AFM, which combines the GHz electrical characterization capabilities, using network-analysis concepts from telecommunications, with the nanoscale resolution imaging capabilities of the AFM.
To complement these methods, we have pursued the combination of optical and electrochemical methods pioneered by the team in Paris; and innovative applications of nanopipette methods and the creation of nanoelectrochemical cells for trapping and characterising a wide variety of single entities (from molecules to nanoparticles) developed by the teams in Leeds, Warwick, and Twente.
A major focus of the team has been on multifunctional analysis, with multichannel probes (developed by Warwick) that can carry out simultaneous analysis of topography, membrane charge, permeability, stimulation-detection, and other functions at the nanoscale, to define a new-state-of-the-art for single cell analysis. Secondly, it explored new transduction mechanisms for the detection and identification of single macromolecules such as nucleic acids based on impedance spectroscopy and nanogap electrodes (Twente), that created new paradigms for single molecules analysis.This work was published in peer reviewed journals and in conferences.
Also, we used a range of complementary methods developed by Bochum, Warwick, and Paris to study the electrocatalytic properties of solid-state nanoparticles. This work has advanced our understanding of electrocatalysis at the nanoscale (structure-activity relationships) and will guide in the future the rational development of the next generation catalysts. We addressed individual particles immobilised on nanoelectrodes; impact experiments, where the response of nanoparticles impinging from solution onto an electrode is measured; single-particle optical tracking and spectroscopy; correlative electrochemical microscopy, bringing together electrochemical images with complementary microscopy, such as AFM and various electron microscopies.
