Biomolecular Electronics Research Laboratory

General

The Biomolecular Electronics Research Laboratory, director Dónal Leech, was established in Galway in 1997. Research in the laboratory focuses on the preparation and characterisation of electron-transfer catalysts and modified electrode surfaces directed to eventual application as biomolecular electrochemical energy generation or detection platforms and devices. The research laboratory is located in the Ryan Institute of the National University of Ireland, Galway (NUIG), and the laboratory is affiliated to the National Centre for Biomedical Engineering Sciences of NUIG.

The fundamental reactions that form the basis of most of our studies are electron transfer reactions. We have a particular interest in electron transfer reactions at the solid/liquid interface and in harnessing biomolecular electron transfer events.  The research programme is aimed at developing eventual applications in bioelectrochemical diagnostics and sensors, biomolecular interaction platforms, biofuel cell prototypes,  bio- and electrochemical bleaching methodologies, and trace metal monitoring systems in ocean environments. We have in addition a research effort that seeks to underpin these areas of application, focused on synthesis and characterisation of electrode modifiers, separations science and surface analytical techniques, and electrochemical and biochemical methods. Should you require any further information on our research programme please browse our research themes below and our publications pages, or contact Dr. Dónal Leech, details in footnote.

Research Themes in the Biomolecular Electronics Research Laboratory

Mediated bioelectrochemistry

In general, electron transfer to and from active sites of redox enzymes is difficult to achieve because they are buried in an insulating protein shell. Several groups have developed successful strategies for directly addressing these buried redox sited in enzymes and proteins. We are however interested in mediating electron transfer to these sites by modification of electrode surfaces with redox enzymes co-immobilized with a redox complex. The redox complex can function as an artificial substrate (electron transfer mediator) enabling addressing of enzyme turnover in the presence of co-substrate. Reagentless enzyme activity sensors can thus be designed by selection of oxygenase enzymes, such as the laccases, that use the redox mediator as substrate and oxygen as the co-substrate, and can be utilized to detect any substance that modulates this activity.

In addition to using such modified electrodes as sensors, they can also be tailored as electrodes in a biocatalytic fuel cell system. This research area proposes the ambitious goal of developing an implantable, miniature, low-power, membrane-less biofuel cell. One approach to the design of an implantable biofuel cell prototype is to exploit the oxidation of fuels, such as glucose, coupled to the reduction of dissolved dioxygen. This may be accomplished by mediated electron transfer from a sugar-oxidising biofilm at the anode to an oxygen-reducing biofilm at the cathode. The output of the cell is the product of the cell voltage and the cell current. Again, a redox mediator can shuttle electrons between the biofilm and the electrode surface. For further information on this area of research, visit the web-sites of the EU FP6 Strategic Research Project, BIOMED-NANO, co-ordinated by D. Leech (2006-2009) and FP7 Small Project 3D-nanobiodevice, co-ordinated by S. Shleev in Malmoe University.

We have also an interest in harnessing microbial action on wastes and renewable biomass for power generation: microbial bioenergy and fuel cells. For further information on this area of research, visit the web-site of the Parsons Research Project, BIOGEN, co-ordinated by D. Leech and V. O’Flaherty (Microbiology). 
 
A further area of interest to us in mediated bioelectrochemistry is the use of enzymes and electron transfer mediators for the oxidative bleaching of pulp and paper (depolymerisation of the coloured lignin). Wood pulp, must be bleached if it is to be used in the finer varieties of light coloured paper. Effluents from conventional bleaching processes using chlorine or chlorine dioxide contain toxic chlorinated chemicals. Thus, environmental concerns have opened up new opportunities for biotechnology and competing technologies to replace current bleaching routines. We have discovered a process for bleaching of pulps using oxidative enzymes and redox complexes as electron transfer mediators. We aim to explore further this process by synthesising novel, improved, electron transfer mediators, to investigate replacing enzymes as oxidants with electrodes (i.e. electrochemical bleaching) and to evaluate the capability of both these processes for bleaching pulps. Ultimately this research may lead to novel, cost-effective, bleaching strategies that are environmentally benign.

Electrochemical receptor-ligand binding assays

The area focuses on developing strategies for electrochemical transduction of biomolecular recognition events (receptor-ligand binding) using redox-active reporting. One approach, for example, is to incorporate an enzymatic amplificiation of a binding event using avidin/biotin interactions and bioelectrocatalysis (see publications). The research includes synthesis and characterisation of novel redox reporter complexes and polymers, investigation of methods for their co-immobilisation in films on electrodes with biorecognition elements, characterisation of the films and surfaces, and investigation of their applications as platforms for unravelling biomolecular interactions on microchips using their electrochemical response as a bioelectronic signal.

Synthesis, Electroanalysis, Separation Science, Surface Analysis, Biochemical Methods

In addition to underpinning the specific research projects outlined above, we have an ongoing research drive in the areas of Synthesis, Electroanalysis, Separation Science, Surface Analysis.

• The synthesis programme is targetted at producing novel redox mediators, electrode modifiers and polymer supports to further the research area of the laboratory.
• Our programme in electroanalysis, aims to use advanced electrochemical methods and instrumentation for trace metal monitoring in  ocean environments, through the Metals in the Marine Environment Group, a joint effort with Dr.s Rachel Cave and Dagmar Stengel.
• The separation science programme supports our synthetic efforts using HPLC, GC and CE instruments coupled to UV-Vis, Fluorescence, Electrochemical and Mass Spectrometric detectors. For example one aspect was a jointly funded project by Bristol-Myers Squibb with Dublin City University, under the Centre for Bioanalytical Sciences, focused on the use of capillary electrophoresis coupled to electrochemical detection for quality control and monitoring in biopharmaceutical manufacturing processes.
• Our surface analytical efforts aim to support our main research programme on modification of electrode surfaces, using spectroscopic (IR, XPS, UV-Vis) and microscopic (SEM, TEM, AFM) methods to characterise our electrodes.

• Disclaimer
• Privacy
• Copyright
• Accessibility