Hogan - Electrochemistry, photochemistry, chemical sensing and biosensing
Our group conducts a range of both fundamental and applied multidisciplinary research focused on expanding the bounds of Analytical Science.
We pursue the development of new chemistries and new technologies which will result in exquisitely low detection limits and enhanced selectivity. Building on our advances in fundamental science, we seek to develop novel sensing technologies and miniaturised instruments for use outside the laboratory setting.
Working at the interface of electrochemistry and photochemistry, we have pioneered several new approaches to detection science. Our group is a world leader in the application of electrochemiluminescence (ECL) detection to mobile phone readable paper microfluidic sensors and the development of potential resolved multi-coloured ECL or 3D ECL.
Mobile phone-based chemical sensors and biosensors
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.
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 applications of highly luminescent complexes of Ruthenium, Iridium and Platinum
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.