Molecular Electronics, Nano-scale chemistry and Sensory Interfaces
Directed Molecular Construction
We are developing methods by which chemically-specific molecular coupling reactions can be initiated and controlled with nanometre resolution using scanning catalytically-active probes. The patterned surface created by this chemical (catalytic) lithography is analysed by Scanning Probe Microscopy (both Atomic Force and Scanning Tunnelling), spectroscopic and fluorescence imaging methods. The ability to selectively engineer surface chemistry with this degree of resolution opens up the possibility that such produced nanostructures be used as templates for the construction of more complex (three-dimensional) molecular assemblies, of potential considerable application in polymer science, biotechnology, sensing and optoelectronics. To date, it has been possible to confine (organometallic Heck, Suzuki, Sonagishara) molecular coupling to sub-zeptomolar (a few tens of molecules) limits/linewidths.
Functional and Sensory Surfaces
With research teams at Cambridge and Rutherford Appleton, orientated peptideaptamer modified surfaces are being generated and screened by a host of electrical (MOSFET), electrochemical, optical methods for their ability to detect specific (disease target) proteins at femtomolar levels.
We are engaged in numerous programs associated with the generation of receptive interfaces; these may be bioelectrochemical, biosensing, protein sensing or based on host-guest chemistry.
With Professor Paul Beer, anion receptors, including those based on interlocked rotaxanes are desiged and self-assembled on both planar electrode surfaces (for electroanalytical detection) and metallic/semiconducing nanoparticle surfaces (fluorescence, plasmon and electroanalytical sensing).
Molecular Electronics
In recent years there has been an explosion of interest in the potential application of single molecules and molecular arrays in electronics. The groups specific interest lies in the analysis of potentially redox or optically switchable molecules (some of which are biological). These projects involve the use of scanning probe tunnel junctions and those fabricated lithographically or electrochemically.
Redox linked Optics
Through appropriate molecular design, it is possible to link optical output to redox state and, in so doing, establish a means of optically following the process of electron transfer to molecules. In recent work, the group have focussed on assessing the activity and redox characteristics of both enzymes and metalloproteins. In some cases this can be performed at the level of the individual molecule.
The group have established an imaging centre (The Nikon Oxford Molecular Imaging Centre) with Nikon UK designed at integrating state-of-the-art optics with sensory, redox or cellular interfaces.