University of Strathclyde

David Birch is Professor of Photophysics at the University of Strathclyde.

He has published over 200 research papers, mainly on fluorescence lifetime spectroscopy. His present research focuses on fluorescence at the biomedical interface in the study of nanoparticles, melanin structure and photophysics, fibril formation in neurology, biomarkers for cancer detection and continuous glucose monitoring.

David studied physics at the University of Manchester where his PhD on diphenylpolyene fluorescence was supervised by John B Birks. After lecturing at Manchester he moved into industry to work on high-resolution organic mass spectrometry with VG Micromass Ltd. His interests subsequently returned to fluorescence when he moved to Strathclyde University where he was appointed Professor of Photophysics in 1993. David was Head of Department from 2004 -10, a period leading up to the Government-led REF 2014 research assessment in which the Department was ranked 1st for research quality across all UK university physics departments.

External appointments include: in 1999 the Sir C V Raman Endowment Visiting Chair at the University of Madras, in 2000 a Visiting Professorship at Kyoto Institute of Technology, from 2002 the Visiting Chair of Applied Physics at the Czech Technical University and in 2014 the Green Honors Chair at Texas Christian University. He is a Fellow of Scotland’s National Academy and a member of the Permanent Steering Committee of the Methods and Applications in Fluorescence conference series. He is Editor-in-Chief of the Institute of Physics journal Measurement Science and Technology and joint founding Editor-in-Chief of one of the Institute’s newest journals, Methods and Applications in Fluorescence. He has served on the Editorial Board of SPIE’s Journal of Biomedical Optics since its launch in 1996.
David is a Director and co-founder of IBH, one of the earliest Scottish University spin-out companies. The Company manufactures fluorescence lifetime instruments and joined Horiba Scientific in 2003.



Using fluorescence for nanoparticle metrology with 0.1 nm resolution

There is growing awareness of the environmental and health consequences that might be associated with the proliferation of nanoparticles, particularly those in the 1-10 nm range that can traverse cellular membranes. Hand-in-hand with this interest goes the search for improved methods of measuring nanoparticle size for research, the need for low cost, more portable and easy-to-use methods that would facilitate wider monitoring, and the need for internationally agreed standards. A recent European Commission report [1] on measurement methods for nanoparticles serves to underline the importance of the topic and provides a useful summary of the main techniques in current use such as light scattering, small angle x-ray scattering (SAX), small angle neutron scattering (SANS) and scanning and transmission electron microscopy (SEM and TEM respectively).

Although fluorescence is a phenomenon that enables many different types of measurement [2], it is not usually associated with metrology. Nevertheless some years ago the  Photophysics group at Strathclyde University introduced an alternative approach to conventional methods for measuring 1-10 nm nanoparticles dispersed in solution that is based on measuring the decay of fluorescence anisotropy of dye bound to a nanoparticle undergoing Brownian rotation. It has been shown to be capable of ~ 0.1 nm resolution and yet is of lower cost and easier to use than SAX, SANS, SEM and TEM. So far this has proved quite successful using a range of both electrostatically and covalently attached dyes in studies of silica nanoparticles growing during the sol-gel process [3,4] and stable LUDOX colloids that are promising metrology standards [5]. 

In this talk I will describe the basics behind fluorescence nanoparticle metrology, outline the main errors to be overcome and describe how recent developments in dye technology promise to make studies at the present day limit of measurement more routine. 


  • Linsinger T P J, Roebben G, Gilliland D, Calzolai L, Rossi F, Gibson N, Klein C 2012 Requirements on measurements for the implementation of the European Commission definition of the term “nanomaterial”. European Commission Joint Research Centre Report. doi 10.22787/63490
  • Birch D J S, Chen Y and Rolinski O J 2015 Fluorescence. Photonics: Scientific Foundations, Technology and Applications, Volume IV, Biological and Medical Photonics, Spectroscopy and Microscopy. Ed. D L Andrews. Wiley. Ch.1. 1-58.
  • Birch D J S and Geddes C D 2000 Sol-gel particle growth studied using fluorescence anisotropy: an alternative to scattering techniques. Phys. Rev. E 62 2977–80.
  • Yip P, Karolin J and Birch D J S 2012 Fluorescence anisotropy metrology of electrostatically and covalently labelled silica nanoparticles. Meas. Sci. Technol. 23 084003.
  • Apperson K, Karolin J, Martin R W and Birch D J S 2009 Nanoparticle metrology standards based on the -resolved fluorescence anisotropy of silica colloids. Meas. Sci. Technol. 20 025310.