keyword
MENU ▼
Read by QxMD icon Read
search

Upconversion nano

keyword
https://www.readbyqxmd.com/read/29881851/near-infrared-triggered-antibacterial-and-antifungal-photodynamic-therapy-based-on-lanthanide-doped-upconversion-nanoparticles
#1
Yuxiang Zhang, Ping Huang, Dong Wang, Jincan Chen, Wenzhen Liu, Ping Hu, Mingdong Huang, Xueyuan Chen, Zhuo Chen
An alarming worldwide increase in microbial resistance to traditional drugs and classical pharmacophores has spurred the search for new antimicrobial compounds. Antimicrobial photodynamic therapy (aPDT) has recently emerged as an effective modality for the selective destruction of bacteria and other pathogenic microorganisms. However, some of the factors, including the aggregation of the hydrophobic photosensitizer (PS) in aqueous media and the inefficient biodistribution of PS limit its expansion to clinical conditions...
June 8, 2018: Nanoscale
https://www.readbyqxmd.com/read/29878021/fluorescence-immunosensor-for-cardiac-troponin-t-based-on-f%C3%A3-rster-resonance-energy-transfer-fret-between-carbon-dot-and-mos-2-nano-couple
#2
Satyabrat Gogoi, Raju Khan
In this study, we demonstrated a prompt and sensitive detection technique for cardiac troponin T (cTnT) in buffer and biological fluid (serum) using an NIR-active fluorescent anti-cTnT-labelled carbon dot (CD) and molybdenum disulfide (MoS2)-based nano-couple. Exfoliated MoS2 nanosheets strongly grasp the anti-cTnT-labelled CDs over their surface, and an excited-state non-radiative energy transfer mechanism takes place from CDs to MoS2, thereby quenching the upconversion fluorescence. The nonlinear and upward Stern-Volmer relationship is observed, which indicates a combined static and dynamic quenching...
June 20, 2018: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/29780568/anisotropic-functionalization-of-upconversion-nanoparticles
#3
Wei Ren, Shihui Wen, Sherif Abdulkader Tawfik, Qian P Su, Gungun Lin, Lining A Ju, Michael J Ford, Harshad Ghodke, Antoine M van Oijen, Dayong Jin
Despite significant advances toward accurate tuning of the size and shape of colloidal nanoparticles, the precise control of the surface chemistry thereof remains a grand challenge. It is desirable to conjugate functional bio-molecules onto the selected facets of nanoparticles owing to the versatile capabilities rendered by the molecules. We report here facet-selective conjugation of DNA molecules onto upconversion nanoparticles via ligand competition reaction. Different binding strengths of phosphodiester bonds and phosphate groups on DNA and the surfactant molecules allow one to create heterogeneous bio-chemistry surface for upconversion nanoparticles...
May 14, 2018: Chemical Science
https://www.readbyqxmd.com/read/29741178/a-temperature-sensor-based-on-the-enhanced-upconversion-luminescence-of-li-doped-naluf-4-yb-3-tm-3-er-3-nano-microcrystals
#4
Qinping Qiang, Shanshan Du, Xinlong Ma, Wenbo Chen, Gangyi Zhang, Yuhua Wang
In this paper, fluorescent and optical temperature sensing bi-functional Li+-doping NaLuF4:Ln (Ln = Yb3+, Tm3+/Er3+) nanocrystals were synthesized via a simple hydrothermal method using oleic acid as a capping ligand. The crystal phase, size, upconversion (UC) properties, and optical temperature sensing characteristics of the crystals can be easily modified by Li+ doping. The results reveal that additional Li+ can promote the transformation from the hexagonal phase to the cubic phase and reduce the size of the nanocrystals...
July 3, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/29722259/multifunctional-optical-sensors-for-nanomanometry-and-nanothermometry-high-pressure-and-high-temperature-upconversion-luminescence-of-lanthanide-doped-phosphates-lapo-4-ypo-4-yb-3-tm-3
#5
Marcin Runowski, Andrii Shyichuk, Artur Tymiński, Tomasz Grzyb, Víctor Lavín, Stefan Lis
Upconversion luminescence of nano-sized Yb3+ and Tm3+ codoped rare earth phosphates, that is, LaPO4 and YPO4 , has been investigated under high-pressure (HP, up to ∼25 GPa) and high-temperature (293-773 K) conditions. The pressure-dependent luminescence properties of the nanocrystals, that is, energy red shift of the band centroids, changes of the band ratios, shortening of upconversion lifetimes, and so forth, make the studied nanomaterials suitable for optical pressure sensing in nanomanometry. Furthermore, thanks to the large energy difference (∼1800 cm-1 ), the thermalized states of Tm3+ ions are spectrally well-separated, providing high-temperature resolution, required in optical nanothermometry...
May 23, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29653217/customizing-poly-lactic-co-glycolic-acid-particles-for-biomedical-applications
#6
REVIEW
Edyta Swider, Olga Koshkina, Jurjen Tel, Luis J Cruz, I Jolanda M de Vries, Mangala Srinivas
Nano- and microparticles have increasingly widespread applications in nanomedicine, ranging from drug delivery to imaging. Poly(lactic-co-glycolic acid) (PLGA) particles are the most widely-applied type of particles due to their biocompatibility and biodegradability. Here, we discuss the preparation of PLGA particles, and various modifications to tailor particles for applications in biological systems. We highlight new preparation approaches, including microfluidics and PRINT method, and modifications of PLGA particles resulting in novel or responsive properties, such as Janus or upconversion particles...
June 2018: Acta Biomaterialia
https://www.readbyqxmd.com/read/29653053/scalable-direct-writing-of-lanthanide-doped-kmnf-3-perovskite-nanowires-into-aligned-arrays-with-polarized-up-conversion-emission
#7
Shuo Shi, Ling-Dong Sun, Ying-Xian Xue, Hao Dong, Ke Wu, Shi-Chen Guo, Bo-Tao Wu, Chun-Hua Yan
The use of one-dimensional nano- and microstructured semiconductor and lanthanide materials is attractive for polarized-light-emission studies. Up-conversion emission from single-nanorod or anisotropic nanoparticles with a degree of polarization has also been discussed. However, microscale arrays of nanoparticles, especially well-aligned one-dimensional nanostructures as well as their up-conversion polarization characterization, have not been investigated yet. Herein, we present a novel and facile paradigm for preparing highly aligned arrays of lanthanide-doped KMnF3 (KMnF3 :Ln) perovskite nanowires, which are good candidates for polarized up-conversion emission studies...
May 9, 2018: Nano Letters
https://www.readbyqxmd.com/read/29493665/lanthanide-doped-upconversion-nanoparticles-complexed-with-nano-oxide-graphene-used-for-upconversion-fluorescence-imaging-and-photothermal-therapy
#8
Po Li, Yue Yan, Binlong Chen, Pan Zhang, Siling Wang, Jing Zhou, Haiming Fan, Yiguang Wang, Xiaonan Huang
In recent years, multifunctional nanoparticles have attracted much research interest in various biomedical applications such as biosensors, diagnosis, and drug delivery systems. In this study, we report an NIR imaging diagnosis and therapy nanoplatform which is developed by complexing upconversion nanoparticles (UCNP@OA) NaLuF4:Er3+,Yb3+ with nanographene oxide (NGO). The obtained nanocomposites UCNP@NGO showed excellent stability and low cell toxicity, which not only acted as upconversion luminescence (UCL) probes for tumor imaging, but also served as therapy agents by converting laser energy into thermal energy for photothermal therapy (PTT) with high photothermal conversion efficiency...
March 26, 2018: Biomaterials Science
https://www.readbyqxmd.com/read/29459928/nano-graphene-oxide-ucnp-ce6-covalently-constructed-nanocomposites-for-nir-mediated-bioimaging-and-ptt-pdt-combinatorial-therapy
#9
Arif Gulzar, Jiating Xu, Dan Yang, Liangge Xu, Fei He, Shili Gai, Piaoping Yang
NIR light-induced imaging-guided cancer therapy is an encouraging route in the cancer theranostic field. Herein, we describe a novel nanoscale proposal, which is established by covalently implanting core-shell structured upconversion nanoparticles (UCNPs) with nanographene oxide (NGO) by a process utilizing polyethylene glycol (PEG), and consequently loading Chlorin e6 (Ce6) onto the surface of NGO. The acquired NGO-UCNP-Ce6 (NUC) nanocomposites can not only be employed as upconversion luminescence (UCL) imaging probes of cells and whole-body animals with high contrast for diagnosis, but also can generate reactive oxygen species (ROS) under 808 nm light excitation for photodynamic therapy (PDT); over and above, they can swiftly and proficiently translate the 808 nm photon into thermal energy for photothermal therapy (PTT)...
March 12, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/29260178/highly-luminescent-eu-sm-mn-doped-cas-up-down-conversion-nano-particles-application-to-ultra-sensitive-latent-fingerprint-detection-and-in-vivo-bioimaging
#10
Jikai Wang, Ni He, Yanli Zhu, Zhengbin An, Ping Chen, Craig A Grimes, Zhou Nie, Qingyun Cai
Due to their unique properties, rare-earth doped upconversion luminescence (UCL) nanomaterials are of considerable scientific interest. Meanwhile, alkaline-earth sulfide materials based on a completely different electron trapping (ET) mechanism demonstrate extremely high UCL efficiencies, which are several dozens of times more than those of conventional fluoride UCL nanomaterials. However, the large particle size, easy hydrolysis, and difficulty in achieving uniform dispersion have precluded bioassay applications...
January 16, 2018: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/29148493/chemical-sensing-and-imaging-based-on-photon-upconverting-nano-and-microcrystals-a-review
#11
Simon Christ, Michael Schäferling
The demand for photostable luminescent reporters that absorb and emit light in the red to near-infrared (NIR) spectral region continues in biomedical research and bioanalysis. In recent years, classical organic fluorophores have increasingly been displaced by luminescent nanoparticles. These consist of either polymer or silica based beads that are loaded with luminescent dyes, conjugated polymers, or inorganic nanomaterials such as semiconductor nanocrystals (quantum dots), colloidal clusters of silver and gold, or carbon dots...
August 13, 2015: Methods and Applications in Fluorescence
https://www.readbyqxmd.com/read/29062116/facile-synthesis-and-emission-enhancement-in-naluf-4-upconversion-nano-micro-crystals-via-y-3-doping
#12
Hao Lin, Dekang Xu, Anming Li, Lu Yao, Zhiren Qiu, Shenghong Yang, Yueli Zhang
A series of Y3+ -absent/doped NaLuF4 :Yb3+ , Tm3+ nano/micro-crystals were prepared via a hydrothermal process with the assistance of citric acid. Cubic nanospheres, hexagonal microdisks, and hexagonal microprisms can be achieved by simply adjusting the reaction temperature. The effect of Y3+ doping on the morphology and upconversion (UC) emission of the as-prepared samples were systematically investigated. Compared to their Y3+ -free counterpart, the integrated spectral intensities in the range of 445-495 nm from α-, β-, and α/β-mixed NaLuF4 :Yb3+ , Tm3+ crystals with 40 mol% Y3+ doping are increased by 9...
October 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28876356/a-versatile-upconversion-surface-evaluation-platform-for-bio-nano-surface-selection-for-the-nervous-system
#13
Libing Fu, Marco Morsch, Bingyang Shi, Guoying Wang, Albert Lee, Rowan Radford, Yiqing Lu, Dayong Jin, Roger Chung
There is considerable interest in developing diagnostic nanotools for early detection and delivery of various therapeutic agents for treatment of neurodegenerative diseases. However, a key challenge remains in the selection of suitable surfaces to overcome the nano-bio interface issue, namely that many nanoparticle surfaces demonstrate instability when administered into biological environments and show substantial cytotoxicity to the central nervous system. In this study, we fabricated an evaluation platform for bio-nano surface selection based on the combination of upconversion nanoparticles (UCNPs), cultured neural cells and zebra fish, and systemically demonstrated how it can evaluate the suitability of nanoparticle surfaces for applications in the central nervous system...
September 21, 2017: Nanoscale
https://www.readbyqxmd.com/read/28686275/power-dependent-upconversion-quantum-yield-of-nayf-4-yb-3-er-3-nano-and-micrometer-sized-particles-measurements-and-simulations
#14
Martin Kaiser, Christian Würth, Marco Kraft, Iko Hyppänen, Tero Soukka, Ute Resch-Genger
Photophysical studies of nonlinear lanthanide-doped photon upconverting nanoparticles (UCNPs) increasingly used in biophotonics and photovoltaics require absolute measurements of the excitation power density (P)-dependent upconversion luminescence (UCL) and luminescence quantum yields (ΦUC ) for quantifying the material performance, UCL deactivation pathways, and possible enhancement factors. We present here the P-dependence of the UCL spectra, ΦUC , and slope factors of the different emission bands of representative 25 nm-sized oleate-capped β-NaYF4 :17% Yb3+ , 3% Er3+ UCNPs dispersed in toluene and as powder as well as ΦUC of 3 μm-sized upconversion particles (UCμP), all measured with a newly designed integrating sphere setup, enabling controlled variation of P over four orders of magnitude...
July 20, 2017: Nanoscale
https://www.readbyqxmd.com/read/28608687/upconverting-nanoparticles-as-optical-sensors-of-nano-to-micro-newton-forces
#15
Alice Lay, Derek S Wang, Michael D Wisser, Randy D Mehlenbacher, Yu Lin, Miriam B Goodman, Wendy L Mao, Jennifer A Dionne
Mechanical forces affect a myriad of processes, from bone growth to material fracture to touch-responsive robotics. While nano- to micro-Newton forces are prevalent at the microscopic scale, few methods have the nanoscopic size and signal stability to measure them in vivo or in situ. Here, we develop an optical force-sensing platform based on sub-25 nm NaYF4 nanoparticles (NPs) doped with Yb(3+), Er(3+), and Mn(2+). The lanthanides Yb(3+) and Er(3+) enable both photoluminescence and upconversion, while the energetically coupled d-metal Mn(2+) adds force tunability through its crystal field sensitivity...
June 13, 2017: Nano Letters
https://www.readbyqxmd.com/read/28411809/temperature-sensing-and-bio-imaging-applications-based-on-polyethylenimine-caf-2-nanoparticles-with-upconversion-fluorescence
#16
Guofeng Liu, Zhen Sun, Zuoling Fu, Li Ma, Xiaojun Wang
Rare earth ion-doped upconversion nanoparticles (UCNPs) have become a research hotspot for their applications such as nano-thermometry and bio-imaging. Here we report one pot solvothermal synthesis of polyethylenimine (PEI) coated CaF2 : 1%Er3+ , 2%Yb3+ UCNPs with good water-solubility and biocompatibility. The nanoparticles show a spherical shape with an average size of 40nm and display intense green light (Yb3+ and Er3+ ) under the 980nm irradiation. The maximum sensitivity of temperature sensing in the biological temperature range is obtained to be 0...
July 1, 2017: Talanta
https://www.readbyqxmd.com/read/28364630/charge-convertibility-and-near-infrared-photon-co-enhanced-cisplatin-chemotherapy-based-on-upconversion-nanoplatform
#17
Jiating Xu, Ye Kuang, Ruichan Lv, Piaoping Yang, Chunxia Li, Huiting Bi, Bin Liu, Dan Yang, Yunlu Dai, Shili Gai, Fei He, Bengang Xing, Jun Lin
Optimal nano-sized drug carrier requires long blood circulation, selective extravasation, and efficient cell uptake. Here we develop a charge-convertible nanoplatform based on Pt(IV) prodrug loaded NaYF4 :Yb,Tm upconversion nanoparticles (UCNs), followed by coating a layer of PEG-PAH-DMMA polymer (UCNs-Pt(IV)@PEG-PAH-DMMA). The polymer endows the platform with high biocompatibility, initial nano-size for prolonged blood circulation and selective extravasation. Especially, the anionic polymer can response to the mild acidic stimulus (pH ∼6...
June 2017: Biomaterials
https://www.readbyqxmd.com/read/28292235/paramagnetic-and-superparamagnetic-inorganic-nanoparticles-for-t1-weighted-magnetic-resonance-imaging
#18
Leyong Zeng, Di Wu, Ruifen Zou, Tianxiang Chen, Jinchao Zhang, Aiguo Wu
Magnetic resonance imaging (MRI) has become a promising technique in the early diagnosis of cancers, especially the application of contrast agents can further enhance the detection limitation. Compared with the dark signal in "negative" contrast agents (T2), "positive" contrast agents (T1) with bright signal are more desirable for high-resolution imaging. However, the clinical used gadolinium complexes have short circulation time and the risk of nephrogenic system fibrosis. Therefore, to overcome the disadvantage of T2 agents and traditional T1 agents, it is very interesting to develop nano-scaled T1-weighted MRI contrast agents with safer and more precise imaging performance...
March 14, 2017: Current Medicinal Chemistry
https://www.readbyqxmd.com/read/28221018/low-efficiency-upconversion-nanoparticles-for-high-resolution-coalignment-of-near-infrared-and-visible-light-paths-on-a-light-microscope
#19
Sriramkumar Sundaramoorthy, Adrian Garcia Badaracco, Sophia M Hirsch, Jun Hong Park, Tim Davies, Julien Dumont, Mimi Shirasu-Hiza, Andrew C Kummel, Julie C Canman
The combination of near-infrared (NIR) and visible wavelengths in light microscopy for biological studies is increasingly common. For example, many fields of biology are developing the use of NIR for optogenetics, in which an NIR laser induces a change in gene expression and/or protein function. One major technical barrier in working with both NIR and visible light on an optical microscope is obtaining their precise coalignment at the imaging plane position. Photon upconverting particles (UCPs) can bridge this gap as they are excited by NIR light but emit in the visible range via an anti-Stokes luminescence mechanism...
March 8, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28134295/solar-pumping-upconversion-of-interfacial-coordination-nanoparticles
#20
Ayumi Ishii, Miki Hasegawa
An interfacial coordination nanoparticle successfully exhibited an upconversion blue emission excited by very low-power light irradiation, such as sunlight. The interfacial complex was composed of Yb ions and indigo dye, which formed a nano-ordered thin shell layer on a Tm2 O3 nanoparticle. At the surface of the Tm2 O3 particle, the indigo dye can be excited by non-laser excitation at 640 nm, following the intramolecular energy transfer from the indigo dye to the Yb ions. Additionally, the excitation energy of the Yb ion was upconverted to the blue emission of the Tm ion at 475 nm...
January 30, 2017: Scientific Reports
keyword
keyword
168975
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"