Assessing cellular internalisation of carbon nanodots doped with gadolinium using correlative optical microscopy and nanofocused synchrotron

We have developed a series of 7-9 nm Carbon nanodots (CNDs) doped with Gd (III) (Gd-CND). They present good stability, biocompatibility and r1 relaxivity values comparable with those of clinical contrast agents, making them interesting as multimodal nanomaterials for Magnetic Resonance Imaging(MRI) and theragnostic applications. ICP-MS show high Gd accumulation in cells treated with Gd CNDs, suggesting that they might penetrate inside cells (desired for new contrast agents). Unfortunately, this could not be confirmed using confocal microscopy or TEM, as those techniques cannot detect intracellular Gd-CNDs. As such, we intend to acquire correlative organelle fluorescence probe Cryo-CLEM and XRF tomograms from cells treated with our Gd-CND at ID16A. This will allow us to obtain 3D information on the localisation of the material within cells with sub-cellular resolution, helping to assess their potential as viable MRI and theragnostic agents for bioimaging and biomedical applications.