Mesoporous nanoparticles Gd₂O₃@mSiO₂/ZnGa₂O₄:Cr³⁺,Bi³⁺ as multifunctional probes for bioimaging

Red/near infrared (NIR) persistent luminescent nanoparticles (PLNPs) hold great potential as a new generation of probes for the detection and imaging of biomolecules. Based upon the consideration that a single nanoprobe could serve multiple purposes, the development of a multimodal nanoprobe that combined the properties of rechargeable persistent emitting luminescence, magnetic resonance imaging (MRI) and drug delivery has attracted our attention as a promising prospect in the field of nanotechnology directed toward biomedical applications. Herein, Gd₂O₃@mSiO₂/ZnGa₂O₄:Cr³⁺,Bi³⁺ (ZGOCB) mesoporous nanoparticles that exhibit enhancement of red (∼695 nm) persistent luminescence (∼18 d) properties were synthesized by using mesoporous silica nanospheres both as morphology-controlling templates and vessels. Being composed of hybrid shell/core architecture and through surface functionalization, Gd₂O₃@mSiO₂/ZGOCB mesoporous nanoparticles possess the capacity for in vivo and in situ real-time monitoring, targeting tumors and drug delivery. Simultaneously, Gd₂O₃@mSiO₂/ZGOCB exhibits a prominent longitudinal relaxivity, indicating that these nanoparticles could also be used as magnetic resonance imaging agents. We believe that this rechargeable red persistent luminescence and MRI-based core/shell structure of the multimodal nanoprobe offers a promising nano-platform for both diagnostics and therapeutics of reactive species in living cells or in vivo.