Upconversion nanotubes with tunable fluorescence properties based on Gd ₂ O ₂ S:Ln ³⁺ (Ln ³⁺  = Yb ³⁺ , Er ³⁺ ) and derivatives for photodynamic therapy

Abstract

In this study, Gd 2 O 2 S:Ln 3+ (Ln 3+ = Yb 3+ , Er 3+) upconversion nanotubes (UCNTs) were synthesised by using Gd(OH) 3 :Ln 3+ (Ln 3+ = Yb 3+ , Er 3+) nanotubes as the template. The luminescent and biological properties of Gd 2 O 2 S:Ln 3+ (Ln 3+ = Yb 3+ , Er 3+) UCNTs, along with photodynamic therapy (PDT) applications of the Gd 2 O 2 S:8%Yb 3+ ,2%Er 3+ UCNT-Ce6 (chlorin e6) nanocomposites, were systematically studied. The resultant UCNTs showed excellent biocompatibility with human retinal pigment cells (ARPE-19) even after a prolonged incubation time of 72 h, and could be used as luminescent probes. Microscopic imaging revealed that the UCNTs existed mainly in cytoplasm. PDT studies on the Gd 2 O 2 S:8%Yb 3+ ,2%Er 3+ UCNT-Ce6 nanocomposites indicate that the growth of the tumour (cell) could be inhibited dramatically when it was injected (incubated) with Gd 2 O 2 S:8%Yb 3+ ,2%Er 3+ UCNT-Ce6 nanocomposites under the irradiation of 980 nm laser.

An Overview of Gadolinium-Based Oxide and Oxysulfide Particles: Synthesis, Properties, and Biomedical Applications

“…Research into lanthanide-based materials emerged in the early 1990s with the development of high-efficiency materials for optics: new fiber amplifiers, stable solid-state lasers, sensors, devices with upconversion, devices with non-linear responses, among others [1]. At present, the interest in investigating Gd 2 O 3 and Gd 2 O 2 S has increased notably in the biomedical field [2,3]. This is due to the excellent optical response of both compounds that can be syntonized in a wide spectral range, from high energy photons (X-ray) to radiation considered transparent to the biological window (750-950 nm) [4].…”