Smart Chemical and Biological Sensing Technologies
Friday 16th June 2017
held at The Royal Society of Chemistry, Burlington House, Piccadilly, London
A Conference report by – Sam Cobb – University of Warwick
The Ninth in the Series of the Sensors Conferences of the Automation and Analytical Management Group (AAMG) was held on the 16th of June 2017 on the topic of Smart Chemical and Biological Sensing Technologies at the Royal Society of Chemistry, Burlington House, Piccadilly, London. The scope of the meeting allowed for a wide range of talks across a variety of topics with presenters from across the UK, both from industry and academia.
The first presentation was by Professor Julian Gardner (University of Warwick) on CMOS gas sensors for healthcare. The presentation covered the potential of CMOS gas sensors as a cheap and commercially viable sensor technology and in particular their integration with smart phones for the personalised healthcare market. The presentation highlighted the key challenges facing sensing technology for this market, in particular the implications of cost and power on the commercial viability of the device. Future areas of interest were also discussed with the potential for application to more challenging biomarkers such as those associated with early diagnosis of cancer from breath samples noted as a potential future application.
This presentation was followed by Professor Mark Bradley (University of Edinburgh) on behalf of the EPSRC ‘Proteus’ interdisciplinary research collaboration, who discussed optical imaging techniques for the diagnosis and characterisation of pulmonary diseases. The presentation discussed the development of an optical fibre based device that allowed for in vivo imaging of bacterial infection in the lungs and its further characterisation to classify the infection allowing for appropriate treatment, continuing the theme of ‘personalised’ healthcare.
The first session continued with a presentation from Professor Phil Bartlett (University of Southampton) on the discrimination of DNA from bio-threats with electrochemical surface enhanced Raman spectroscopy. The technique was presented as a method for distinguishing between wild-type and mutated DNA using electrochemical melting experiments, for instance for diagnosing conditions such as cystic fibrosis. Also discussed was the application of this technique to distinguishing threats such as yersina pestis which is responsible for bubonic plague from other similar but less dangerous bacteria such as yersina pseudotuberculosis. Finally it was shown how the technique could be used to discriminate between different strains of the same bacteria which could possibly shed light on the origin of the bio-threat.
The penultimate presentation in this session was from Dr Licia Dossi (University of Cranfield) on the development of a colorimetric detection method for numerous threats including drugs, explosives and their precursors. The method demonstrated the use of multiplexing to look for numerous different threats in one sample and the use of signal processing made it possible to turn an optical image into a form that needed little user interpretation to detect multiple threats in one sample. The presentation also highlighted how the project has progressed through several forms of prototype to reach its current form.
The final presentation in this session was by Mr Glenn Sunley Saez (University of Manchester) on the topic of electrolyte gated OFET’s and the integration of microfluidics for biosensor applications. In this paper the state of the art was discussed with recent results discussing the development of the microfluidic device and the optimisation of the system to improve sensor to sensor and measurement to measurement reproducibility. The paper also discussed potential future applications of this technology as a biosensor.
The second session opened with a presentation by Professor Paula Mendes (University of Birmingham) on making smarter biological interfaces for sensing, who discussed the design and fabrication of switchable sensors that can be used to detect species on demand, and also the intracellular detection of reactive oxygen species using carbon nanotube based devices.
The next presentation was by Dr Nathan Lawrence (ANB sensors) on the development of a pH sensor for oceanographic applications and its use to compete in the Wendy Schmidt ocean health X prize, in which the sensor came second in the affordability category. The presentation discussed the use of surface modification of carbon electrodes with a variety quinone species to give a pH sensitive electrochemical response. Further discussions were on the synthetic design of quinone species to try and improve the pH response of the sensor in low-buffered media and also on the work to address the issues with conventional reference electrode technologies in these systems, in particular when performing measurements over a long time period.
Following this was a presentation by Dr Zoë Ayres (University of Warwick) which was also on the topic of pH sensing. A sensor based on laser-micromachined boron doped diamond was demonstrated, which offers an alternative to the conventional glass pH electrode. The sensor was shown to be insensitive to oxygen and also not affected by common interferants such as sodium and lithium ions. A route to pH sensing in low and unbuffered media was also demonstrated as by lowering and controlling the surface coverage of the quinone species used to detect the pH. A sensor that did not significantly perturb the local proton concentration was demonstrated to work in unbuffered media with a linear response to pH shown.
The penultimate presentation of the session was by Dr Jiri Hromadka (University of Nottingham) on the development of an optical fibre based gas sensors, which discussed the fabrication of optical gratings by modifying the refractive index of a fibre using a laser and using this in combination with layer by layer deposition of metal organic frameworks to detect carbon dioxide. Promising results showed quantitative CO2 detection and the application of the technology to other gases was discussed.
The final presentation was given by My Sebastian Nufer (M Solv Ltd.) on the development of graphene based gas sensors. Sensor design and fabrication using laser micromachining was discussed, along with the limitations of commercially available graphene platelets. An inter-sheet resistance based mechanism was demonstrated for the detection of ammonia gas.
Two posters were also presented at the conference. One by Mr Sam Cobb (University of Warwick) that discussed the creation and control of sp2 carbon in boron doped diamond for pH measurements in unbuffered solutions and the second by Mr Haytham Hussein (University of Warwick) which covered the electrochemical recovery and deposition of palladium from acetonitrile- water mixed solvents.
In summary the meeting presented a wide range of sensing technologies including but not limited to optical, electronic and electrochemical measurements based devices. The scope of the meeting also covered devices at a wide range of development stages, from early proof of concept devices to commercially ready systems. The wide range of promising devices presented shows the current strength of the field but also delegates engaged in numerous discussions regarding the future challenges and opportunities for the community, some of which may be addressed at future conferences on Sensors.
Photographs courtesy of John Trigg