Optofluidic microreactors for exploration of novel enzyme mimics

Natural enzymes are exceptionally well-suited to aid the manufacturing of high value products. However, their applications have been limited to few types of enzymes and only a handful of chemical processes they catalyse. Among the general limitations of the enzyme design, one significant limitation is the exploration and validation of the enzyme activity. The use of flavin-based enzymes has been explored to inspire the design of new types of hybrid photocatalysts useful for manufacturing processes, in particular synthesis of novel dyes and pharmaceutical compounds. The study of photocatalytic systems is also of great interest in the field of renewable fuel sources. Solar energy can be converted to chemical fuels through artificial photosynthesis systems, in which photosensitizers play a key role. Commonly used photosensitizers include molecular dyes, TiO2 nanoparticles and semiconductors such as CdSe and CdS. However, dyes are often expensive and difficult to prepare, TiO2 nanoparticles have poor aqueous dispersibility and Cd based systems are toxic and suffer from low elemental abundance[8]. This has led to the emergence of carbon-nanodots (CND) as attractive photosensitizer alternatives. They are low-cost, non-toxic, simple to chemically modify, water soluble and stable.

This project will aim to overcome one of the main barriers to advancing the fields of enzyme-mimetic photocatalysts and carbon nanodot (CND) photosensitizers: the lack of quantitative in-situ analysis methods for small reaction volumes. The use of optofluidic microreactors will allow rapid screening of various photocatalytic reactions, acting to develop a greater understanding of the underlying mechanisms involved. Hollow-core photonic crystal fibres (HC-PCF) will be immobilised with either flavin catalysts or CND through various different immobilisation strategies to create novel photocatalytic microreactors. These microreactors will be used for ultrasensitive spectroscopy within small reaction volumes, including methodologies such as UV-vis, Raman and fluorescent spectroscopy. This will allow robust characterisation of photocatalytic reaction dynamics, steady-state reaction conditions and identification of reaction intermediates and products. Advancing the state of the art will have huge implications for green catalysis, sustainable manufacturing and green solar fuel production. By creating an optical fibre microreactor to study light-driven catalysis, this project closely aligns with the catalysis, analytical science and sensors and instrumentation EPSRC research areas.

The primary outputs from the CDT will be cohorts of highly qualified, interdisciplinary postgraduates who are experts in a wide range of sensing activities. They will benefit from a world leading training experience that recognises sensor research as an academic discipline in its own right. The students will be taught in all aspects of Sensor Technologies, ranging from the physical and chemical principles of sensing, to sensor design, data capture and processing, all the way to applications and opportunities for commercialisation, with a strong focus in entrepreneurship, technology translation and responsible leadership. Students will learn in extensive team and cohort engaging activities, and have access to cutting-edge expertise and infrastructure. 90 academics from 15 different departments participate in the programme and more than 40 industrial partners are actively involved in delivering research and business leadership training, offering perspectives for impact and translation and opportunities for internships and secondments. End users associated with the CDT will benefit from the availability of outstanding, highly qualified and motivated PhD students, access to shared infrastructure, and a huge range of academic and industrial contacts.

Immediate beneficiaries of our CDT will be our core industrial consortium partners (MedImmune, Alphasense, Fluidic Analytics, ioLight, NokiaBell, Cambridge Display Technologies, Teraview, Zimmer and Peacock, Panaxium, Silicon Microgravity, etc., see various LoS) who incorporate our cross-leverage funding model into their corporate research strategies. Small companies and start-ups particularly benefit from the flexibility of the partnerships we can offer. We will engage through weekly industry seminars and monthly Sensor Cafés, where SME employees can interact directly with the CDT students and PIs, provide training in topical areas, and, in turn, gain themselves access to CDT infrastructure and training. Ideas can be rapidly tested through industrially focused miniprojects and promising leads developed into funded PhD programmes, for which leveraged funding is available through the CDT.

Government departments and large research initiatives are formally connected to the CDT, including the Department for the Environment, Food and Rural Affairs (DEFRA); the Cambridge Centre for Smart Infrastructure and Construction (CSIC); the Centre for Global Equality (CGE); the National Physics Laboratory (NPL); the British Antarctic Survey (BAS), who all push our CDT to generate impacts that are in the public interest and relevant for a healthy and sustainable future society. With their input, we will tackle projects on assisted living technologies for the ageing population, diagnostics of environmental toxins in the developing world, and sensor technologies that help replace the use of animals in research. Developing countries will benefit through our emphasis on open technologies / open innovation and our exploration of responsible, ethical, and transparent business models. In the UK, our CDT will engage directly with the public sector and national policy makers and regulators (DEFRA, and the National Health Service - NHS) and, with their input, students are trained on impact and technology translation, ethics, and regulatory frameworks.