Hogan - Electrochemistry, photochemistry, chemical sensing and biosensing
We conduct strategic fundamental research to develop new materials, molecules and molecular detection techniques. We translate these discoveries into biosensor technologies for real-world applications including medical diagnostics and environmental monitoring.
For example, we:
Pursue the development of new chemistries and molecular detection techniques that result in exquisitely low detection limits and enhanced selectivity, and
Develop novel sensing technologies and miniaturised instruments to enable laboratory-grade performance at the point of need.
We work at the interface of electrochemistry and photochemistry, collaborating with chemists, biochemists, physicists, materials scientists, electronic engineers and software engineers, to make scientific breakthroughs in detection science.
We have pioneered several new approaches to molecular detection, including:
The application of electrochemiluminescence (ECL) detection using a mobile phone and paper microfluidic sensors; and a Raspberry Pi single-board computer and low-cost sensors.
The development of potential-resolved, multi-colour ECL (or 3D ECL).
Android voltammetry, a patented technique enabling instrument-free voltammetry using mobile devices like smartphones.
We used ultra-low-cost paper microfluidic sensors produced by ink jet printing for electrochemiluminescence-based detection for the first time. Significantly, we demonstrated that the luminescent emission could be initiated electrochemically using the audio output of a mobile phone as a function generator; and simultaneously captured by using the in-built camera as a photodetector.
Such mobile phone based biosensing promises to make environmental testing and medical diagnostics more widely available, especially in resource-poor environments and remote areas. Read more in Analytica Chimica Acta.
We have also used low-cost sensors combined with a Raspberry Pi-based instrument to perform electrochemiluminescence-based immunoassays. The instrumentation is significantly cheaper than laboratory equivalents; portable; and with analytical performance similar to conventional instrumentation. This approach is promising to enable biosensing at the point-of-need without sacrificing analytical performance. Read more in Bioelectrochemistry.
Tuning luminescent emission colour via electrode potential
We have demonstrated that selective electrochemiluminescence (ECL) of several Ruthenium and Iridium complexes simultaneously in solution can be controlled by the applied electrode potential. These luminescent redox systems create a range of exciting new possibilities for multiplex ECL detection and colour tunable light-emitting devices.
Synthesis and sensing application of highly luminescent complexes of Ruthenium, Iridium and Platinum, and organic compounds
The detection of biologically and environmentally relevant molecules, at ultralow concentration demands the development of new luminophores and electrochemiluminophores with intense emission in a variety of colours. Cyclometallated Ir(III) complexes such as Ir(ppy)3 and Ir(ppy)2(L)+, where ppy = 2-phenylpyridine and L is an auxiliary ligand such as a derivative of triazole, bipyridine or phenanthroline, display an intriguing combination of luminescent and electrochemical properties. The electrochemiluminescence (ECL) of these compounds, where the excited state is formed by applying a suitable voltage, can be quite exceptional.
We seek to tune the luminescent and redox characteristics of these complexes by varying one or more of the ligands. The colour of the emission, for example, can be varied from blue to red. There is a vast range of possibilities for novel, highly luminescent sensing molecules based on bis- or tris- cyclometallated complexes.
