Multifunctional Gadolinium‐Doped Mesoporous TiO<sub>2</sub> Nanobeads: Photoluminescence, Enhanced Spin Relaxation, and Reactive Oxygen Species Photogeneration, Beneficial for Cancer Diagnosis and TreatmentRoghayeh Imani, Aleš Iglič, Detlef W. Bahnemann et al.|Small|2017Cited by 64