Cardiff University President's Research Scholarship: Bioimaging - Optical biosensors based on imaging of whispering-gallery modes in microsphere resonators (PhD Studentship)
Reference Number: R791
Key Studentship Information
This is a Cardiff University President's Research Scholarship, part of a new £4M investment to coincide with the inauguration of Professor Sir Martin Evans (Nobel Prize for Medicine 2007) as Cardiff’s new President. All of the University Schools and Research Centres offering opportunities under the programme have demonstrated the real potential of the Scholarships to contribute to research excellence through significant, challenging and original PhD research projects and excellent PhD supervision and support. Other attractive features of the Scholarships include the presence of multiple President’s Scholars in each of the research areas and the guaranteed exposure of President’s Scholars to innovative technologies, theories, methodological approaches, and debates. More information on the President's Research Scholarships scheme is available here: www.cardiff.ac.uk/presidents
Project Title: Optical biosensors based on imaging of whispering-gallery modes in microsphere resonators
Project Description:
During the last decade, label-free optical biosensors have become valuable tools for clinical and military use as well as drug discovery. They are important devices for a range of applications going from detection of infectious agents, toxins, proteins, and DNA to investigation of whole cell behaviour. Modern label-free optical biosensors, such as the widely utilized surface plasmon resonance (SPR) method are based on an evanescent light field travelling along a planar surface, probing the target material deposited on the surface. Recently, a novel type of biosensor based on evanescent field coupling has been proposed [1]. This sensor exploits narrow-linewidth photonic resonances of dielectric microspheres, the so-called whispering-gallery modes (WGMs). These light modes are travelling inside the sphere close to its surface by repeated total internal reflection. Molecular binding to the sphere outer surface creates a change of the optical polarisability in the evanescent field of the WGMs, which is detected as a change in the resonance wavelength. Since the light in WGMs can orbit many thousand times before escaping the resonator, the detection sensitivity of this method as compared to planar surface-based methods is expected to be greatly enhanced.
In our Biophotonics group at Cardiff University we have developed a monolithic biosensor based on sharp WGMs of polystyrene microspheres in water attached onto an optical coupler via a solid separation layer index matched to water [2]. The objective of this project is (i) to scale the sensor into a multiplex system where several microspheres are coupled to a waveguide array, and to demonstrate parallel and sensitive detection of many analytes. (ii) to use imaging of the WGMs on the surface to enable detection of the analytes distribution or shape. The project will be primarily of experimental nature and will involve the construction, optical characterisation, and application of the sensor. This will be supported by theoretical modelling [3,4,5] through collaboration with the theory group in the School of Physics and Astronomy at Cardiff University. The applications of the sensor will be in collaboration with the School of Pharmacy detecting bio-markers for diagnosis of diseases.
[1] F. Vollmer and S. Arnold, Nature Methods 5, 591 (2008)
[2] Julie Lutti, Wolfgang Langbein and Paola Borri Appl. Phys. Lett 93, 151103 (2008).
[3] L. Chantada, N. I. Nikolaev, A. L. Ivanov, P. Borri, and W. Langbein, J. Opt. Soc. Am. B 25, 1312 (2008).
[4] E.A. Muljarov, W. Langbein and R. Zimmermann, Europhysics Lett. 92, 50010 (2010).
[5] M. B. Doost, W. Langbein, and E. A. Muljarov, Phys. Rev. A 85, 023835 (2012)
Supervisor: Wolfgang Langbein (PHYSX) with Biophotonics group in BIOSI
Start Date: 1st October 2012
Funding
The award will cover full UK/EU tuition fees plus a doctoral stipend matching the UK Research Council minimum (£13,590).
Number of Awards Available: 1
Eligibility
Academic Criteria: Applicants must have a First Class Honours degree or a 2.1 plus a postgraduate Masters degree (or their equivalents).
Applicants whose first language is not English will be required to demonstrate proficiency in the English language (IELTS 6.5 or equivalent).
Residency: Open to all UK/EU students without further restrictions.
How to Apply
No separate application is necessary.
Using the online application service, applicants must complete a research PhD application for the School of the lead supervisor (Physics in this case) with a starting date of 01/10/2012.
Applicants should name the Subject of Research ‘Bioimaging’ and indicate the title of project, then under ‘Method of funding’ state that they are applying for a President's Research Scholarship.
Application Deadline: Applications will be considered on a rolling basis.
Further Information
For more information contact:
Email: LangbeinWW@cardiff.ac.uk
Telephone: +44 (0)29 208 70172
