Prof. Jacobsen's group develops novel methods, instruments, and analysis approaches for X-ray nanoscale imaging and applies them to biology and environmental science, using the Advanced Photon Source (APS) at Argonne. Directions: (1) Scanning X-ray fluorescence microscopy (SXFM) for organ-wide and nanoscale elemental mapping of metals (zinc, copper, iron) in biological tissues — central to the NIH-funded QE-Map national resource; imaging how metals regulate cellular functions, synaptic zinc signaling, and neurodegenerative disease; (2) X-ray ptychography and coherent diffractive imaging (CDI) for nanoscale biological imaging beyond the diffraction limit with improved dose efficiency; (3) Development of new algorithms, optics (zone plates), and detector systems to push spatial resolution and dose efficiency in X-ray microscopy — including lensless imaging methods and compressed-sensing reconstruction. Joint appointment at Argonne National Laboratory (Argonne Distinguished Fellow); also involved in QE-Map resource with Kozorovitskiy and Hao Zhang (McCormick).

Designs programmable DNA nanodevices as quantitative fluorescent reporters to map second messengers in real time inside specific organelles of living cells. Research directions: (1) DNA origami ion-sensing nanodevices for pH, Cl-, Ca2+, HOCl, and membrane voltage with single-organelle addressability; (2) targeting nanodevices to endosomes, lysosomes, mitochondria, and ER to dissect organelle biology and disease mechanisms; (3) in vivo deployment in C. elegans and Drosophila. NIH Director's Pioneer Award 2022.