Hybrid Nanoclusters for Near-Infrared to Near-Infrared Upconverted Persistent Luminescence Bioimaging

Abstract

Persistent luminescence (PL) bioimaging provides an optimal method of eliminating autofluorescence for a higher resolution and sensitivity because of the absence of excitation light. However, ultraviolet light is still necessary in common energy charging processes, which limits its reactivation in vivo because of its low penetration depth. In the present study, we introduce a type of hybrid nanocluster (UCPL-NC) composed of upconversion nanoparticles, β-NaYbF:Tm@NaYF, and persistent nanoparticles, ZnGaGeO:0.5%Cr, which can be activated by a 980 nm laser and exhibits an afterglow at 700 nm to realize near-infrared (NIR) to NIR UCPL bioimaging. The PL of the UCPL-NCs can be reactivated even when covered with a 10 mm pork. We demonstrate that these polyethylene glycol-modified phospholipid-functionalized UCPL-NCs can be reactivated in vivo and applied in the PL lymphatic imaging on small animals.

Impact of Lanthanide Nanomaterials on Photonic Devices and Smart Applications

“…Thus a rechargeable excitation modality via NIR light for deep in vivo imaging has been achieved. As shown in Figure , recent works have contributed to design the NIR‐to‐NIR LPNPs and apply them to in vivo imaging . Further applications will be tributary of a feasible concept for efficient recharge of the PLNPs.…”

“…Upconversion PL makes it possible to achieve PL bioimaging activation in vivo and the decay time is not a limitation to PL bioimaging anymore because of the increased penetration depth of NIR excitation. Reproduced with permission . Copyright 2017, American Chemical Society.…”

Recent Progress in Time‐Resolved Biosensing and Bioimaging Based on Lanthanide‐Doped Nanoparticles

“…In the past decade, different kinds of lanthanide‐doped PLNPs have been developed and their biomedical applications have been largely explored, such as in α‐fetoprotein and ascorbic acid detection as well as targeted tumor imaging . Moreover, vis‐to‐NIR or NIR‐to‐NIR lanthanide‐doped PLNPs that can be repeatedly charged in vivo have been developed for achievement of deep tissue and long‐term bioimaging . Due to these unique properties, lanthanide‐doped PLNPs have become ideal probes for highly sensitive biosensing and high resolution bioimaging.…”

“…Recently, lanthanide‐doped upconversion PLNPs that can be activated with 980 nm laser have been developed. The PLNPs can be repeatedly excited in vivo, enabling long‐term bioimaging with high signal‐noise ratio, minimal phototoxicity and deep tissue penetration …”

“…Because these new PLNPs can be in situ and repeatedly excited with 980 nm excitation, they are ideal for autofluorescence‐free and long‐term bioimaging. Li and co‐workers designed upconversion persistent luminescence nanocomposites composed of upconversion nanoparticles and persistent luminescence nanoparticles . In their design, the excitation energy could be absorbed by UCNPs and then transferred to PLNPs, leading to the generation of persistent luminescence.…”