Compared to traditional macroelectrodes, nanoscale electrodes have tremendous potential as electrochemical sensors exhibiting enhanced performance. As critical dimensions of the electrodes enter the nano regime, 3D analyte diffusion profiles to the electrode dominate with a corresponding increase in mass transport, higher current densities giving rise to an increase in the ratio of faradaic to charging current, higher signal to noise ratios, steady-state sigmoidal voltammograms, low depletion of target molecules, low supporting electrolyte concentration requirements and shorter RC time constant. In this talk, I present our work on molecular and ion diffusion simulations to explore molecular transport behaviour at individual nanoelectrodes and nanoelectrode arrays. I report on the design fabrication and in-depth electrochemical analysis of discrete gold nanowire and nanowire array electrodes for use in electrochemical-based sensing applications. The electrochemical responses of single nanowire electrodes in model redox mediators were excellently described by Butler-Volmer kinetics. Consequently, highly sensitive detection of chemical and biochemical species; for a variety of different applications in the environmental and AgTech sectors, has been demonstrated using these devices. Finally, I will present new work employing generator-collector architectures using interdigitated nanowire arrays whereby we can tailor the local pH of a solution to undertake chemical detection without the need to add additional reagents.

Plasmonic crystals are a class of optical metamaterials that consist of engineered structures at the sub-wavelength scale. They exhibit optical properties that are not found under normal circumstances in nature, such as negative-refractive-index and epsilon-near-zero (ENZ) behavior. Graphene-based plasmonic crystals present linear, elliptical, or hyperbolic dispersion relations that exhibit ENZ behavior, normal or negative-index diffraction. The optical properties can be dynamically tuned by controlling the operating frequency and the doping level of graphene. We propose a construction approach to expand the frequency range of the ENZ behavior. We demonstrate how the combination of a host material with an optical Lorentzian response in combination with a graphene conductivity that follows a Drude model leads to an ENZ condition spanning a large frequency range.

Quorum sensing is a communication mechanism used by bacteria to coordinate density dependent collective behavior. In the particular case of bacterial growth, quorum sensing acts as control mechanism that strikes the right balance between intrinsic growth rate and carrying capacity. Herein a model for controlled bacterial growth via quorum sensing in continuous time is proposed. The optimization of the sensing threshold is considered. Numerical evidence suggests that the a discounted objective function based on the growth curves is unimodal. Growth curves obtained in experiments match the ones predicted by the model.

Quantum communication via satellites offers up a paradigm shift in telecommunications. Providing for unparalleled communication security, this emerging technology will also lead us into the development of the global quantum internet. This research area was given a large boost recently with the launch of the World's first quantum satellite by China. This new satellite creates entangled photon pairs, beaming them down to Earth for subsequent processing and use in a range of communication scenarios. The next frontier in this area is the development of a quantum communication `satellite-swarm’ – a formation of small inexpensive nano-satellites working together to route quantum information over large distances in the vacuum of space. The development of such a network has motivated much effort in the design of new miniaturised quantum-enabled technologies that can operate efficiently in the harsh environment of space. In this talk I review these efforts and discuss how some of the new techniques being developed could also be used for quantum communications at the nano-scale. Development of nano-scale quantum communication is vital for interfacing different processing sites within future quantum computers and for the connections of those quantum computers to the wider quantum internet.

The vision of a quantum internet is to fundamentally enhance Internet technology by enabling quantum communication between any two points on Earth. While the first realisations of small scale quantum networks are expected in the near future, scaling such networks presents immense challenges to physics, computer science and engineering. Here, we provide a gentle introduction to quantum networking, and survey the state of the art. We proceed to discuss key challenges for computer science and engineering in order to make such networks a reality.

Apart from the effect of path loss and signal-dependent molecular absorption noise, the capabilities of in-vivo nanocommunication at the Terahertz (THz) frequencies are also strictly influenced by the distribution of power transmission in the frequency domain. In this paper, artificial skin with different fibroblast cell densities are considered as THz communication mediums, signal-to-noise ratio (SNR) and channel capacity as a function of the transmitted signal power for f lat and Gaussian-shaped distribution is quantified. In addition, the achievable communication distance of THz communication inside the artificial skin is evaluated. The results show that -30 dBW using flat distribution and -40 dBW with Gaussian distribution can provide optimal SNR without posing more energy requirement on nano-transceivers. The achievable communication range in dermal equivalent is strictly limited to about 1 to 2 mm. Gaussian-shaped power distribution can provide higher SNR but lower capacity comparing with flat distribution. These results provide fundamentals in building future intra-body nanonetworks.