Alfa Chemistry provides upconversion nanoparticles for a wide range of biomedical applications, including in vitro bioimaging, in vivo bioimaging, bioassays, immunohistochemistry, microarray detection, photodynamic therapy, and photocontrolled drug activation.
Upconversion nanoparticles convert near-infrared radiation of lower energy to visible radiation of higher energy through a nonlinear optical process. The doping concentration and size of upconversion nanoparticles can be customized to your specific requirements.
Our upconversion nanoparticles can be oil or water dispersible. By precise surface modification, the upconversion nanoparticles are available in PEG-NH2, PEG-COOH, TiO2, and SiO2 capped forms. These luminescent nanoparticles can be used for bioimaging, molecular recognition, and photodynamic therapy.
They can be used in the following fields：
Highly sensitive bioimaging
Light-responsive drug release
Photosensitizers in photodynamic therapy
Upconversion nanoparticles (UCNPs) exhibit anti-Stokes emission when excited in the near-infrared (NIR) region, i.e., the photon energy emitted is higher than the excitation energy. The material system achieves this by converting two or more IR photons into visible photons. The use of IR is beneficial for bioimaging because of its deeper penetration into biological tissues and lack of self-fluorescence. Lim et al. demonstrated that upconverted rare-earth oxides UCNPs, synthesized by combustion, below 10 nm, can be stably suspended in water when modified with amines. The amine-modified UCNPs exhibited specific surface immobilization on patterned gold surfaces. Finally, the low toxicity of UCNPs was verified by testing on multicellular Cryptobacterium hidradenum.
Fig. 1 HRTEM image of sub-10 nm UCNPs. (Lim et al., 2009)
Immunoassays based on down-conversion target materials (organic dyes or quantum dots) lead to rather strong spectral interference between the encoded and reported signals, which severely affects the detection accuracy and hinders its application. Zhang et al. designed and successfully prepared a novel up-conversion nanocrystal-encoded magnetic microspheres (UCNMMs). The UCNMMs were obtained by combining magnetic Fe3O4 nanoparticles and upconversion nanocrystals were obtained by combining them with polystyrene microspheres. Since the upconversion nanocrystals (UCNs) and the reporter signal are excited by NIR and UV/visible light, respectively, the UCNMMs-based immunoassay does not experience interference from optical spectra. In addition, these new functionalized UCNMMs have excellent properties in binding biomolecules and rapid separation, which will have great potential for multiplex assays.
Fig.2 Schematic description of the preparation process about upconverting nanocrystals encoded magnetic microspheres (UCNMMs). (Zhang et al., 2016)
Chitosan-coated LaF3:Yb,Er UCNTs were synthesized by a facile one-pot precipitation method by Gayathri et al. XRD analysis confirmed the formation of LaF3 hexagonal phase crystal structure with an average crystal size of 7.6 nm. The nanocrystals were water soluble and highly biocompatible due to surface functionalization using the biopolymer chitosan. The synthesized UCNTs produced intense green fluorescence upconversion emission under near-infrared excitation at 974 nm. The authors conclude that the investigations performed on the cytotoxicity of LaF3:Yb,Er in MCF-7 cells are a substantial step toward the clinical application of upconversion transducers in breast cancer therapy.
Fig. 3 (a, c and d) SEM images of LaF3:Yb,Er capped with chitosan. (b) The surface texture of LaF3:Yb,Er capped with chitosan constructed using Mountains Map®SEM. (Gayathri et al., 2015)
Alfa Chemistry can provide a variety of complex and customized fluorescent quantum dot products. Our products involve perovskites precursors, perovskites quantum dots, quantum dot kit, single layer quantum dots, upconverting nanoparticles and other fluorescent quantum dots. Alfa Chemistry provides products with high fluorescence quantum yield, stable quality and relatively low price. Our products are constantly updated. If the product you need is not in our catalog, please feel free to contact us, we provide relevant custom services.
- Lim, Shuang Fang, et al. Upconverting nanophosphors for bioimaging[J]. Nanotechnology, 2009, 20(40): 405701.
- Zhang, Ying, et al. Multifunctional microspheres encoded with upconverting nanocrystals and magnetic nanoparticles for rapid separation and immunoassays[J]. ACS Applied Materials & Interfaces, 2016, 8(1): 745-753.
- Gayathri, Sethuraman, et al. Chitosan conjugation: A facile approach to enhance the cell viability of LaF3: Yb, Er upconverting nanotransducers in human breast cancer cells[J]. Carbohydrate polymers, 2015, 121: 302-308.
* It should be noted that our service is only used for research, not for clinical use.