Ionogel-biosensor: novel ionogels based on ionic liquids as a platform to measure enzyme activity of glucose oxdase in real time

It is estimated that there are 170 million diabetics worldwide, and the number continues to rise alarmingly. The management of diabetes is therefore critical to future society, and this is driving demand for point-of-care (POC) glucose biosensors, and they play a central role in the management blood sugar levels in patients with diabetes. Glucose Oxidase (GOx) is a biorecognition enzyme, which recognises the glucose molecule and acts as a catalyst to produce gluconic acid and hydrogen peroxide in the presence of glucose and oxygen.[1] Ionic Liquids are organic salts, which are liquid at ambient temperature. Their non-volatile character and thermal stability makes them an attractive alternative to conventional organic solvents. We are interested in studying the characteristics of GOx in ionic liquids, and in polymer materials incorporating ionic liquids known as ionogels. Herein we report the enzyme activity of GOx in a biosensor fabricated using a novel hybrid ionogel. This approach potentially offers several advantages over conventional materials. For example, the ionogels can be chemically and physically tailored for a particular requirement. [3] The design of these ionogels ensures that the enzyme is effectively retained in the polymer, thus preventing leaching. The ionogel-biosensor has been incorporated into a compact, portable and low cost device, which allows the real time monitoring of enzyme activity of GOx. Based on this model, we project that this device will provide the platform for measuring the enzyme activity of a wide range of enzymes

Incorporating Policymaker Costs and Political Competition into Rent-Seeking Games

We incorporate policymaker costs of supplying rents and variable intensities of competition among rent seekers into the standard rent-seeking game. By incorporating these aspects, the game has greater verisimilitude to the lobbying process. The first aspect captures the fact that in rent-seeking contests there is a positive probability that neither firm will obtain the rent. The second aspect captures the fact that firms seeking different rents still must compete for policymakers\u27 resources. We find that lobbying expenditures, rent-seeking profits, and rent dissipation depend on the intensity of competition and the value of the rent relative to policymaker costs. For example, if the value of the rent is sufficiently high relative to policymakers\u27 costs, an increase in the intensity of political competition will increase lobbying expenditures; otherwise, expenditures fall as competitive intensity increases. In addition, the model establishes pure-strategy equilibria with underdissipation where only mixed-strategy equilibria exist in the standard model

Real-time sweat pH monitoring based on a wearable chemical barcode micro-fluidic platform incorporating ionic liquids

This work presents the fabrication, characterisation and the performance of a wearable, robust, flexible and disposable chemical barcode device based on a micro-fluidic platform that incorporates ionic liquid polymer gels (ionogels). The device has been applied to the monitoring of the pH of sweat in real time during an exercise period. The device is an ideal wearable sensor for measuring the pH of sweat since it does not contents any electronic part for fluidic handle or pH detection and because it can be directly incorporated into clothing, head- or wristbands, which are in continuous contact with the skin. In addition, due to the micro-fluidic structure, fresh sweat is continuously passing through the sensing area providing the capability to perform continuous real time analysis. The approach presented here ensures immediate feedback regarding sweat composition. Sweat analysis is attractive for monitoring purposes as it can provide physiological information directly relevant to the health and performance of the wearer without the need for an invasive sampling approac

Monte Carlo inference and maximization for phrase-based translation

Recent advances in statistical machine translation have used beam search for approximate NP-complete inference within probabilistic translation models. We present an alternative approach of sampling from the posterior distribution defined by a translation model. We define a novel Gibbs sampler for sampling translations given a source sentence and show that it effectively explores this posterior distribution. In doing so we overcome the limitations of heuristic beam search and obtain theoretically sound solutions to inference problems such as finding the maximum probability translation and minimum expected risk training and decoding.

Simple barcode system based on ionogels for real time pH-sweat monitoring

This paper presents the fabrication, characterization and the performance of a wearable, robust, flexible and disposable barcode system based on novel ionic liquid polymer gels (ionogels) for monitoring in real time mode the pH of the sweat generated during an exercise period. Up to now sweat analysis has been carried out using awkward methods of collecting sweat followed by laboratory analysis. The approach presented here can provide immediate feedback regarding sweat composition. The great advantage of sweat analysis is the fact that it is a completely non-invasive means of analyzing the wearer's physiological state and ensuring their health and well-being

Antigenic variation in <i>Trypanosoma brucei</i>: joining the DOTs

African trypanosomes, such as &lt;i&gt;Trypanosoma brucei&lt;/i&gt;, are protistan parasites that cause sleeping sickness. Though first described more than a century ago, trypanosomes remain a blight on the health of the human population and on the economy of sub-Saharan Africa. &lt;i&gt;T. brucei&lt;/i&gt; replicates in the bloodstream of infected mammals and traverses the blood-brain barrier to enter the central nervous system in the late, frequently fatal, stages of the disease. Because of its extracellular lifestyle, &lt;i&gt;T. brucei&lt;/i&gt; is continuously exposed to antibody challenge. To circumvent this, the parasite uses antigenic variation of a surface protein named the variant surface glycoprotein (VSG). Around 107 VSG molecules are expressed on the parasite's cell surface, creating a dense coat that prevents adaptive immunity from detecting or accessing invariant antigens. However, antibodies against the expressed VSG are generated, and periodic switches to an immunologically distinct VSG coat are necessary for parasite survival. Such switches are pre-emptive of the immune response and contribute to the pattern of trypanosome growth seen in an infected host (Figure 1): parasite numbers increase, but then drop as VSG-specific antibodies are raised by the host. Cells that have switched to another VSG coat survive this killing and seed the outgrowth of a subsequent peak of parasites, which is again decimated by anti-VSG immune killing. As a survival strategy, antigenic variation succeeds by prolonging the time that the parasite

Ionic liquids for enzymatic sensing

The key challenges currently faced in lab-on-a-chip biochemical sensor developments are device reliability and power consumption. The major issues faced in terms of device reliability are liquid handling over extended periods of time, as the micro-dimensioned fluidic channels are prone to blockage, and unreliable micro pumps/valves. The overall aim of this proposal is to develop a biocompatible molecular sensor that will address these key issues which are holding back biocompatible sensors technologies, and thus to develop an innovative class of sensing technology at the forefront of molecular sensing. [1] Over the past decade conducting polymer electrodes have played an important role in bio-sensing and actuation. [2] Recent developments in the field of organic electronics have made available a variety of devices that bring unique capabilities at the interface with biology. [3,4] One example is organic electrochemical transistors (OECTs) that are being developed for a variety of bio-sensing applications, including the detection of ions, [5] and metabolites, such as glucose [6] and lactate [7]. Room temperature ionic liquids (RTILs) are organic salts, which are liquid at ambient temperature. Their non-volatile character and thermal stability makes them an attractive alternative to conventional organic solvents. [8] To this end, we propose to exploit enzymatic doped ionogels - new materials for inherently biocompatible molecular sensors. These particular sensors are hybrid materials that consist of monomeric components polymerised within biocompatible ionic liquids, thus allowing various platforms for modification. Further investigation shows that these sensing platforms can be incorporated into flexible materials such as carbon cloth and can be utilised for bio-sensing. Furthermore, we envisage that the proposed sensing devices can be incorporated into fabrics for “wearable” health care devices thus providing clear benefits the public health service. Long term ambitions are to build a research career with a focus on academia and industrial research collaborations. The proposed time in DCU would allow myself to demonstrate adaptability and diversity and to highlight the transferable nature of my skills through the publication of peer review articles and the securing of patents. It is hoped that the research and project management experience gained through collaborations and contacts will allow me to further my career through more senior positions and grants. Through current collaborations, engineering and chemistry support from members of the Adaptive Sensor Group has already been secured for the proposed project. Expanding my research profile through further publications and both domestic and international presentations of the research. Existing collaborations held by myself (Doug MacFarlane’s / Ekaterina Izgorodina’s group, Monash University, Gloria Elliott’s group, UNCC, North Carolina and George Malliaras & Róisín Owens at the Ecole Nationale Supérieure des Mines de Saint Etienne) will be of considerable benefit to the project