Stokes emission in GdF₃:Nd³⁺nanoparticles for bioimaging probes

Abstract

There is an increasing interest in rare earth (RE) doped nanoparticles (NPs) due to their sharp absorption and photoluminescence (PL) in the near infrared (NIR) spectral region. These NIR based nanoparticles (NPs) could allow biological imaging at substantial depths with enhanced contrast and high spatial resolution due to the absence of auto fluorescence in biological samples under infrared excitation. Here, we present the highly efficient infrared photoluminescence in GdF3:Nd3+ nanoparticles under 800 nm excitation within the hydrodynamic size limitations for bio-applications. The downconversion (Stokes emission) absolute quantum yield (QY) measurements in powder, poly maleic anhydride- alt-1- octadicene (PMAO) coated powder and colloidal solutions have been investigated. QY measurements have revealed that downconversion(Stokes emission)QY in an average 5 ± 2 nm sized GdF3: 1% Nd3+colloidalNPs are 2000 times higher than efficient upconversion (UC) particles NaYF4: 20 % Er/ 2% Yb of same size. Furthermore, the utility of these NIR emitting nanoparticles forbioimagingprobe has been demonstrated by confocal imaging and spectroscopic study.

Dual mode NIR long persistent phosphorescence and NIR-to-NIR Stokes luminescence in La3Ga5GeO14: Cr3+, Nd3+ phosphor

“…NIR-excitation (808 nm) and NIR-emission (1064 nm) [27,28]. The excitation source of 808 nm is given to 4 present the superiority of successfully avoiding the noteworthy overheating effect due to the strong absorption at 980nm of water in biological system [29]. Wang [30] et al have done this experiment by transferring the NPs into the water.…”

Systematic Studies on RE2Hf2O7:5%Eu3+ (RE = Y, La, Pr, Gd, Er, and Lu) Nanoparticles: Effects of the A-Site RE3+ Cation and Calcination on Structure and Photoluminescence

“…[1][2][3][4] Recently there has been a great amount of interest in the derivative structures, such as A 2 B 2 O 7 , of dioxide BO 2 (e.g. B = Zr, Ce, and Hf) type compounds as RE host materials due to their binary metal cation sites, where the larger A site cation can be replaced with trivalent RE ions and B is a smaller transition metal cation.…”

Magnetic and optical properties of NaGdF4:Nd3+, Yb3+, Tm3+ nanocrystals with upconversion/downconversion luminescence from visible to the near-infrared second window

“…For photoluminescence measurements, finely powdered phosphor samples were pressed into a square cell volume of approximately 14 mm × 7 mm × 2 mm to ensure uniform thickness and distribution of powders. Quantum yield (QY) was measured in a calibrated integrating sphere setup and power density used was 100 W/cm 2 [32]. The synthesized samples were also spin coated on a quartz plate and used for measuring solid state UV-vis-NIR absorption spectra with a Lambda 1,050 UV/vis/NIR (Perkin-Elmer, UK) spectrometer.…”

“…To date, multifunctional NCs that exhibit two or more different properties are highly desirable for many important technological applications such as multifunctional imaging, and simultaneous diagnosis and therapy due to their versatile functionality [20][21][22]. The Nd 3+ ion with an absorption around 800 nm is considered as a good candidate to achieve high downconversion (DC) quantum efficiency and significantly improve the penetration depth for deep-tissue imaging due to the NIR DC emission around 850-1,100 nm [32,33]. Besides, Nd 3+ ions under excitation at 800 nm can also overcome the overheating issues associated with the upconversion (UC) sensitizer Yb 3+ ions under excitation at 980 nm in the UC process [34].…”