Jessica Walker

Jessica is a beamline scientist at I14. Before joining Diamond, she completed her PhD at the University of Edinburgh in chemistry, studying biomineralization in coccolithophores and the influence of biological materials on crystallization. After graduating in 2018, she undertook postdoctoral research at Northwestern University in Evanston, north of Chicago, USA, studying biomineralization in sea urchin embryos, Acantharia and human enamel, using synchrotron techniques at Argonne and Brookhaven National Laboratories, as well as electron microscopy and live cell imaging.

Biomineralization, crystallization, crystal growth, marine biology

My research interests are focused on biomineralization and crystal formation in biological systems. Biomineralization is the formation of hardened tissues by organisms, and occurs across the kingdoms of life. Cellular processes allow organisms to manipulate crystal growth to form specific morphologies and imbue their minerals with properties that precisely suit their functional requirements. I am interested in how organisms control the production of their mineral phases and how their crystallization strategies can transfer to synthetic systems. In particular, I am interested in marine biomineralizing organisms, with a focus on single-celled plankton such as coccolithophores and Acantharia, producers of calcium carbonate and strontium sulfate respectively.

Biominerals are often composites of organic and inorganic materials, and use a variety of materials from calcium carbonate to iron phosphate. The crystals they form can be single-crystalline, arrays of aligned crystals, and crystallographic variations on a nanometre scale. This makes them ideal subjects for study using the hard x-ray nanoprobe.

To understand the processes behind biomineralization, my previous research has touched on several varied disciplines, including cell biology, crystallization in synthetic systems and cryo-electron microscopy for crystal growth and for biological materials.

At Beamline I14, I am developing liquid cell imaging using the techniques available at the beamline (XRF, XANES, DPC and ptychography).

If your research area could match or link to any of these interests, please get in touch with Jessica to discuss potential beamtime applications.

1. Coccolith crystals: pure calcite or organic-mineral composite structures? J. M. Walker, G. Langer, Acta Biomaterialia, 2021

2. Exploiting Colorimetry for Fidelity in Data Visualization, M. J. Waters, J. M. Walker, C. T. Nelson, D. Joester, J. M. Rondinelli, Chemistry of Materials, 32 (13), 5455-5460, 2020

3. Morphological development of Pleurochrysis carterae coccoliths examined by cryo-electron tomography, J. M. Walker, B. Marzec, N. Ozaki, D. Clare, F. Nudelman, Journal of Structural Biology, 210 (1), 107476, 2020

4. Three-dimensional architecture and surface functionality of coccolith base plates, B. Marzec, J. M. Walker, M. Panagopoulou, Y. Jhons, D. Clare, A. Wheeler, M. Shaver, F. Nudelman, Journal of Structural Biology, 208 (2), 127-136, 2019

5. Polymorph Selectivity of Coccolith‐Associated Polysaccharides from Gephyrocapsa Oceanica on Calcium Carbonate Formation In Vitro, J. M. Walker, B. Marzec, R. B. Y. Lee, K. Vodrazkova, S. J. Day, C. C. Tang, R. E. M. Rickaby, F. Nudelman, Advanced Functional Materials, 29 (1), 1807168 2019

6. Solid‐state transformation of amorphous calcium carbonate to aragonite captured by cryoTEM, J. M. Walker, B. Marzec, F. Nudelman, Angewandte Chemie International Edition, 56 (39), 11740-11743, 2017

7. Formation of fluorohydroxyapatite with silver diamine fluoride, M. L. Mei, F. Nudelman, B. Marzec, J. M. Walker, E. C. M. Lo, A.W. Walls, C. H. Chu, Journal of Dental Research, 96 (10), 1122-1128, 2017

8. Alternative Hydrogen Peroxide Sources for Peroxyoxalate “Glowstick” Chemiluminescence Demonstrations, I. A. Smellie, J. K. D. Aldred, B. Bower, A. Cochrane, L. Macfarlane, H. B. McCarron, R. O'Hara, I. L. J. Patterson, M. I. Thomson, J. M. Walker, Journal of Chemical Education, 94 (1), 112-114, 2017