Regulating the trap distribution of ZnGa₂O₄:Cr³⁺ by Li⁺/Ga³⁺ doping for upconversion-like trap energy transfer NIR persistent luminescence

Abstract

Doping Li+/Ga3+ in ZnGa2O4:Cr3+ splits the energy level of electron traps into shallow traps and deep traps, which makes the developed phosphors be successfully excited by a low-energy NIR light and suitable for long-term biological imaging.

Recent advances in near-infrared I/II persistent luminescent nanoparticles for biosensing and bioimaging in cancer analysis

“… Diverse excitation and emission light Without in vivo imaging [ 19 ] ZGGO: Cr 0.02 ,Yx SiO 2 296/697 nm Y 3+ doping improves persistent intensity Without in vivo imaging [ 36 ] LZGG: m Cr 3+ , n Ti 4+ n/a 254/700 nm Systematic investigations of the energy traps Lack of more in-depth biological experimental testing [ 57 ] Zn 1.33 Ga 1.335 Cr 0.005 Sn 0.33 O 4 (ZGSO:0.5%Cr 3+ ) n/a 450/700 nm Impact on the morphological feature Without in vivo imaging [ 30 ] ZnGa 2 O 4 :Cr 3+ with Li + /Ga 3+ n/a Multiple ex./em. Diverse excitation and emission light Lack of more in-depth biological experimental testing [ 26 ] Zn 2 Ga 3.98-4 x /3 Ge x O 8 :Cr 0.02 (ZGGO:Cr) n/a 254/700 nm Bioimaging and biosensing dual functions Lack of more in-depth biological experimental testing [ 58 ] Near-infrared-II (1000–1700 nm) LN-PLN n/a X-ray/multiple em. ...…”

“…In 2017, Jing Wang and his team successfully synthesized PLNs labeled as ZnGa 2 O 4 @MSN@Gd 2 O 3 . Through a high-temperature calcination process, Zn 2+ , Ga 3+ , Cr 3+ , and Sn 4+ were incorporated into mesoporous silica nanoparticles (MSNs) [ 26 ]. Subsequently, Gd 3+ was encapsulated in the outer layer of ZnGa 2 O 4 @MSN using another high-temperature calcination step, resulting in the formation of PLNs with an outer coating of Gd 2 O 3 (ZnGa 2 O 4 @MSN@Gd 2 O 3 ).…”

Nd3+-Doped LiLuF4 Nanoparticles for Near-Infrared/Computed Tomography Dual-Mode Imaging

“…Vascular imaging plays a critical role in the diagnosis, treatment, evaluation, and surgery of various diseases, providing valuable insights into the physiological processes of tissues and organisms, thus facilitating medical interventions. − To overcome the limitations of single-mode imaging, multimodal imaging has emerged as a promising approach that integrates different bioimaging techniques, enabling a more comprehensive analysis of tissues. − For instance, computed tomography (CT) imaging offers excellent spatial resolution (≤50 μm) for hard tissues, while it often lacks sensitivity and molecular specificity . In contrast, fluorescence imaging can achieve multiscale imaging effects from the cellular to the biomolecular level but is hindered by penetration depth .…”

X-ray-Excited Persistent Luminescence of Tb3+-Doped Fluoride Nanoparticles for Photodynamic Therapy

“…After being excited with high-energy photons, persistent luminescent (PersL) materials can store partial excitation energy and then release it slowly under thermal stimulation as long-lasting luminescence. This distinctive optical phenomenon is generally attributed to the capture and release of photogenerated carriers by traps after the cessation of excitation, thus demonstrating great potential in applications of the temperature sensor, anticounterfeiting, − data storage, , and bioimaging. − …”