Advances in Bio-analytical Laser Ionisation Mass Spectrometry

The application of laser ionisation methods has revolutionised mass spectrometry, particularly in the biosciences. The focus of research in our group is the analysis and chemical imaging of complex surfaces including biological cells and tissue. We have pioneered the development and application of Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS). This is a powerful surface analysis technique in which atomic and molecular species are ejected from sample surfaces using a highly focused high-energy ion beam. The ejected ions can be subjected to mass spectrometry directly, building up a chemical image as the ion beam is scanned across the surface. However, the majority of the chemical information is contained in the ejected neutral species, which must be ‘post-ionised’ prior to mass spectrometric detection. This post-ionisation step is most effectively performed with a high power pulsed laser. The investigation and optimization of this laser post-ionisation process is of interest from a fundamental and applied view.

The aim of this project is to study the laser post-ionisation characteristics of a series of molecules of significant biological interest including drugs and metabolites to provide the optimum route for their sensitive detection and imaging in medical and biological research.

Previous work in our laboratory and elsewhere has shown that an effective method of laser post-ionisation of biological molecules is multiphoton ionisation (MPI). Here the crucial thing is the control over the number of photons absorbed by each molecule and the rate of ionisation compared to that of competing processes such as photofragmentation. The use of pico- and femtosecond UV lasers shows considerable promise. An alternative strategy is single photon ionisation (SPI) using high energy (vacuum UV) photons. These photons can be generated from a laser source using nonlinear optical methods.

The student will work closely with other members of our research team using state-of-the-art analytical facilities and lasers in the Manchester Interdisciplinary Biocentre and in the Photon Science Institute. The project is well-suited to a highly motivated student with an interest in fundamental or applied photon science.

Applicants should have or expect a good (I or II(i)) honours degree (or an equivalent degree) in Chemistry.

Please complete an online application using the following web link http://www.manchester.ac.uk/postgraduate/howtoapply/.

For more details please contact Dr Nick Lockyer ([Email Address Removed]).