School of Chemistry Colloquium: Professor David Parker FRS (Durham University)

School of Chemistry Colloquium open to final year project students, MSc students, PhD students, postdoctoral researchers and academic staff.

Professor David Parker FRS of Durham University presents ‘On the Design of Responsive Luminescent Lanthanide Sensors'.

Abstract: A plethora of europium(III) complexes has been designed and developed whose emission lifetime, intensity and circular polarisation respond to variations in pH, pM and pX, both in aqueous media and in cellulo. [1,2]

A mechanistic rationale for complex design has been postulated [1] explaining how the ligand field can be perturbed reversibly [2]. Examples of ‘switch-on' complexes for monitoring receptor or antibody internalisation via time dependent acidification changes have been developed (Figure 1), [3] as well as systems showing chiral selectivity in cell uptake and staining, for which circular polarised luminescence microscopy allows visualisation. [4]

Circularly polarised luminescence (CPL) is the emission analogue of circular dichroism and has been used to signal reversible binding of ADP in the presence of ATP by virtue of their very different Eu(III) probe complex CPL profiles Binding of a terminal phosphate group to europium is favoured by bridging to an integral zinc-binding site. With ADP (and AMP), the helicity of the isomeric adduct is the opposite to that observed with ATP. A similar approach examining total emission intensity changes allows monitoring of the levels of the broad-spectrum herbicide glyphosate, in river water and wheat grain extracts. [5]

[1] D. Parker, J. D. Fradgley and K-L. Wong, Chem. Soc. Rev. 2021, 50, 8193-8213.
[2] D. Parker, E. A. Suturina, I. Kuprov and N. F. Chilton, Acc. Chem. Res. 2020, 53, 1520-1534.
[3], M. Starck, J. D. Fradgley, R. Pal, L. Lamarque, J. M. Zwier, D. Parker, Chem. Eur. J. 2021, 27, 766-777; J. D. Fradgley, M. Starck, M. Laget, E. Bourrier, E. Dupuis, L. Lamarque, E. Trinquet, J. M. Zwier, D. Parker, Chem. Commun, 2021, 57, 5814.
[4] A.T. Frawley, M. Starck, R. Pal and D. Parker, Chem. Sci. 2018, 9, 1042; P. Stachelek, L. MacKenzie, D. Parker and R. Pal, Nature Commun. 2022, 13, 553-560.
[5] L.B. Jennings, S. Shuvaev, M.A. Fox, D. Parker, R. Pal, Dalton Trans, 2018, 47,16145