Novel bifunctional Nd:YAG/Fe₃O₄ nanocomposite as nanothermometer/nanoheater for potential biomedical applications

Abstract

This work reports a novel bifunctional nanocomposite made of infrared-emitting nanophosphors and superparamagnetic nanoparticles, which simultaneously provides heating and temperature sensing at the nanoscale level. Highly luminescent Y3Al5O12:Nd3+ nanophosphors were synthesised by using a sol–gel route and were subsequently mixed with superparamagnetic nanoparticles producing a core–shell structure, which displayed superparamagnetic and fluorescent properties in the same nanostructured system. As a result, this bifunctional nanocomposite showed two essential characteristics: (i) it increased in temperature up to 57 °C upon exposure to an alternating magnetic field of sufficient strength and frequency, and (ii) its temperature could be optically sensed by monitoring the infrared luminescence emitted from the YAG:Nd nanophosphor. Our experiments revealed that the YAG:Nd/Fe3O4@SiO2 nanocomposite possesses excellent luminescence and superparamagnetic properties; both physical properties are driven in a non-contact manner making it appropriate for sensing local heating and temperature of cells, and also suitable to be used in medical treatments with minimal invasiveness.

Stair-Structured Cu2–xHoxO Materials with Adjustable Optical and Magnetic Properties

“…4−6 At present, the optical/magnetic bifunctional materials reported in the literature are mainly composite materials, such as coating materials, mosaic materials, and so on. 7,8 Zhang et al reported the hollow Fe 3 O 4 @SiO 2 @α-NaYF 4 /Yb, Er composite, which can emit visible light under the excitation of near-infrared and has the effect of magnetic targeting under the action of an external magnetic field. 9 Abbas et al found that NaYF 4 :Yb, Er@Fe x O y modified the surface of the shell by a dopamine molecule, which makes the composite nanoparticles more water-soluble and less toxic.…”

“…Seeking ferromagnetic semiconductors with a high Curie temperature and inorganic luminescent materials (phosphors) with a short lifetime is a great challenge in semiconductor spintronics and projection television screen applications. − Bifunctional materials, especially those with both photoluminescence (PL) and magnetism, are widely used in multifunctional devices and biological diagnosis and treatment due to their unique and superior properties. − At present, the optical/magnetic bifunctional materials reported in the literature are mainly composite materials, such as coating materials, mosaic materials, and so on. , Zhang et al reported the hollow Fe 3 O 4 @SiO 2 @α-NaYF 4 /Yb, Er composite, which can emit visible light under the excitation of near-infrared and has the effect of magnetic targeting under the action of an external magnetic field . Abbas et al found that NaYF 4 :Yb, Er@Fe x O y modified the surface of the shell by a dopamine molecule, which makes the composite nanoparticles more water-soluble and less toxic .…”

ZnxMn1–XFe2O4@SiO2:zNd3+ Core–Shell Nanoparticles for Low-Field Magnetic Hyperthermia and Enhanced Photothermal Therapy with the Potential for Nanothermometry

“…31 Besides, Tejada et al worked with YAG: Nd/Fe 3 O 4 @SiO 2 nanocomposites that are excited at 813 nm that showed a thermal sensitivity of 0.14% K −1 . 32 Because PTT is not commonly performed with IONPs, these articles focus only on MNH. Recently, Ortgies et al proposed a poly-lactic-co-glycolic acid encapsulation of multicores (magnetite NPs and LaF 3 :Nd) for trifunction (MNH, PTT, and LNT) operations by showing a thermal sensitivity of 0.4% K −1 evaluated via multiparametric thermometry using two peaks (862.2 and 864 nm) after excitation at 808 nm.…”

“…Dong and Zink encapsulated magnetite NPs and NaYF 4 :Yb 3+ , Er 3+ nanorods in the silica matrix and excited at 980 nm (Yb 3+ ) . Besides, Tejada et al worked with YAG: Nd/Fe 3 O 4 @SiO 2 nanocomposites that are excited at 813 nm that showed a thermal sensitivity of 0.14% K –1 . Because PTT is not commonly performed with IONPs, these articles focus only on MNH.…”