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https://www.readbyqxmd.com/read/30315742/towards-utilising-photocrosslinking-of-polydiacetylenes-pdas-for-the-preparation-of-stealth-upconverting-nanoparticles-ucnps
#1
Anne Nsubuga, Kristof Zarschler, Massimo Sgarzi, Bim Graham, Holger Stephan, Tanmaya Joshi
We demonstrate a novel strategy for preparing hydrophilic upconverting nanoparticles (UCNPs) by harnessing the photocrosslinking ability of diacetylenes (DAs). Replacement of the hydrophobic oleate coating on the UCNPs with 10,12-pentacosadiynoic acid (PCDA), followed by overcoating with diacetylene phospholipid and subsequent photocrosslinking under 254 nm irradiation produces water-dispersible polydiacetylene (PDA)-coated UCNPs. These UCNPs resist the formation of a biomolecular corona and show great colloidal stability...
October 13, 2018: Angewandte Chemie
https://www.readbyqxmd.com/read/30306988/tunable-upconversion-in-a-nanocrystal-organic-molecule-hybrid-reabsorption-vs-resonant-energy-transfer
#2
Chaojun Li, Xiaofeng Liu, Jianrong Qiu
Organic semiconductors, such as polycyclic aromatic hydrocarbons, are typically not responsive to near infrared (NIR) light due to their relatively large bandgaps. Here, we show that the NIR light at 980 nm can be efficiently converted to broadband visible upconversion (UC) emission by rubrene molecules in a solution dispersed with upconversion nanoparticles (UCNPs). Spectroscopic characterizations indicate that the sensitization of emission by rubrene molecules strongly depends on the location of the 4f levels of Er3+ ions and the interplay between reabsorption and Förster-type energy transfer...
October 11, 2018: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/30306654/infrared-sensitive-memory-based-on-direct-grown-mos-2-upconversion-nanoparticle-heterostructure
#3
Yongbiao Zhai, Xueqing Yang, Feng Wang, Zongxiao Li, Guanglong Ding, Zhifan Qiu, Yan Wang, Ye Zhou, Su-Ting Han
Photonic memories as an emerging optoelectronic technology have attracted tremendous attention in the past few years due to their great potential to overcome the von Neumann bottleneck and to improve the performance of serial computers. Nowadays, the decryption technology for visible light is mature in photonic memories. Nevertheless, near-infrared (NIR) photonic memristors are less progressed. Herein, an NIR photonic memristor based on MoS2 -NaYF4 :Yb3+ , Er3+ upconversion nanoparticles (UCNPs) nanocomposites is designed...
October 10, 2018: Advanced Materials
https://www.readbyqxmd.com/read/30291459/a-test-strip-for-ochratoxin-a-based-on-the-use-of-aptamer-modified-fluorescence-upconversion-nanoparticles
#4
Shijia Wu, Lihong Liu, Nuo Duan, Wenyue Wang, Qianru Yu, Zhouping Wang
An aptamer-based test strip is described for visual and instrumental determination of the mycotoxin ochratoxin A (OTA). It is based on the use of NaYF4 :Yb,Er upconversion nanoparticles (UCNPs) as a label for the aptamer and on the competition between OTA and its complementary sequence for an OTA-specific aptamer. To improve the analytical performance, the optical properties of the UCNPs, the fluidity of the UCNP-aptamer conjugate, and the migration rate on the nitrocellulose membranes were investigated. Under the optimal experimental conditions and by using a 980-nm laser, the relative fluorescence intensity (test line value/control line value) is proportional to the logarithm of the OTA concentration over a range from 5 to 100 ng·mL-1 (R2  = 0...
October 5, 2018: Mikrochimica Acta
https://www.readbyqxmd.com/read/30276757/analyte-triggered-cyclic-autocatalytic-oxidation-amplification-combined-with-an-upconversion-nanoparticle-probe-for-fluorometric-detection-of-copper-ii
#5
Hongyu Chen, Kaili He, Huan Li, Youyu Zhang, Shouzhuo Yao
The authors describe an upconversion nanoparticle-based (UCNP-based) fluorometric method for ultrasensitive and selective detection of Cu2+ . The UCNPs show a strong emission band at 550 nm under near-infrared excitation at 980 nm. The principle of the strategy is that gold nanoparticles (AuNP) can quench the fluorescence of UCNP. In contrast, the addition of L-cysteine (Cys) can induce the aggregation of AuNP, resulting in a fluorescence recovery of the UCNPs. On addition of Cu2+ , it oxidizes Cys to cystine and is reduced to Cu+ ...
October 1, 2018: Mikrochimica Acta
https://www.readbyqxmd.com/read/30260566/lighting-up-microrna-in-living-cells-by-the-disassembly-of-lock-like-dna-programmed-ucnps-aunps-through-the-target-cycling-amplification-strategy
#6
Keying Zhang, Shuting Song, Shan Huang, Lin Yang, Qianhao Min, Xingcai Wu, Feng Lu, Jun-Jie Zhu
Intracellular microRNAs imaging based on upconversion nanoprobes has great potential in cancer diagnostics and treatments. However, the relatively low detection sensitivity limits their application. Herein, a lock-like DNA (LLD) generated by a hairpin DNA (H1) hybridizing with a bolt DNA (bDNA) sequence is designed, which is used to program upconversion nanoparticles (UCNPs, NaYF4 @NaYF4 :Yb, Er@NaYF4 ) and gold nanoparticles (AuNPs). The upconversion emission is quenched through luminescence resonance energy transfer (LRET)...
October 2018: Small
https://www.readbyqxmd.com/read/30260218/upconversion-nanoprobes-recent-advances-in-sensing-applications
#7
Zhiming Zhang, Swati Shikha, Jinliang Liu, Jing Zhang, Qingsong Mei, Yong Zhang
Rare earth ions doped upconversion nanoparticles (UCNPs) are capable of stepwisely converting two or more lower energy near-infrared (NIR) excitation photons into a higher energy visible and ultraviolet emission photon, resulting in a large anti-Stokes shift of several hundred nanometers. Because the f-electron configurations of lanthanide ions have abundant energy levels, and many of them possess long lifetimes, UCNPs exhibit unique optical properties including optical tunability over emission wavelengths and lifetimes, better photo-stability and improved monochromatic color-purity and spatial resolution...
September 27, 2018: Analytical Chemistry
https://www.readbyqxmd.com/read/30251526/highly-sensitive-detection-of-microrna-21-with-icpms-via-hybridization-accumulation-of-upconversion-nanoparticles
#8
Xun Liu, Shang-Qing Zhang, Zi-Han Cheng, Xing Wei, Ting Yang, Yong-Liang Yu, Ming-Li Chen, Jian-Hua Wang
A highly sensitive platform is developed for the determination of microRNA-21 (miRNA-21) with inductively coupled plasma mass spectrometry (ICPMS). It includes the following operations: Hairpin structures DNA H1 and H2 are designed, and DNA H1 is bound to ultrasmall lanthanide upconversion nanoparticles (UCNPs) to produce UCNPs@DNA conjugate probes. Target miRNA triggers a chain reaction for alternating hybridization between DNA H1 (bound on UCNPs@DNA probe) and DNA H2. This leads to UCNPs accumulation and serves as an efficient amplification strategy for UCNPs...
October 3, 2018: Analytical Chemistry
https://www.readbyqxmd.com/read/30215515/small-and-bright-lithium-based-upconverting-nanoparticles
#9
Ting Cheng, Riccardo Marin, Artiom Skripka, Fiorenzo Vetrone
In the context of light-mediated tumor treatment, the application of ultraviolet (UV) radiation can initiate drug release and photodynamic therapy. However, its limited penetration depth in tissues impedes the subcutaneous applicability of such radiation. On the contrary, near-infrared (NIR) light is not energetic enough to initiate secondary photochemical processes, but can pierce tissues at a significantly greater depth. Upconverting nanoparticles (UCNPs) unify the advantages of both extremes of the optical spectrum, they can be excited by NIR irradiation and emit UV light through the process of upconversion, effective NIR-to-UV generation being attained with UCNPs as large as 100 nm...
September 28, 2018: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/30208518/layer-by-layer-assembled-pei-based-vector-with-the-upconversion-luminescence-marker-for-gene-delivery
#10
Yaqiong Wang, Ping Cao, Shicui Li, Xiaofeng Zhang, Jin Hu, Mingyue Yang, Sujuan Yao, Feng Gao, Ao Xia, Jian Shen, Xiaohua Huang
The upconversion luminescence (UCL) marker based on upconversion nanoparticles (UCNPs) shows unique advantages over traditional fluorescence markers, such as enhanced tissue penetration, better photostability, and less autofluorescence. Herein, we constructed a new UCL gene-delivery nonviral vector via layer-by-layer self-assembly of poly(ethylene imine) (PEI) with UCNPs. To reduce the cytotoxicity of PEI, citric acid (CA) was introduced for aqueous modification, and PEI assembly was introduced on the UCNP surface...
September 18, 2018: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/30199626/highly-sensitive-visible-blind-wearable-and-omnidirectional-near-infrared-photodetectors
#11
Monika Kataria, Kanchan Yadav, Shu-Yi Cai, Yu-Ming Liao, Hung-I Lin, Tien Lin Shen, Ying-Huan Chen, Yit-Tsong Chen, Wei-Hua Wang, Yang-Fang Chen
Visible blind near-infrared (NIR) photodetection is essential when it comes to weapons used by military personnel, narrow band detectors used in space navigation systems, medicine, and research studies. The technological field of filterless visible blind, NIR omnidirectional photodetection and wearability is at a preliminary stage. Here, we present a filterless and lightweight design for a visible blind and wearable NIR photodetector capable of harvesting light omnidirectionally. The filterless NIR photodetector comprises the integration of distinct features of lanthanide-doped upconversion nanoparticles (UCNPs), graphene, and micropyramidal poly(dimethylsiloxane) (PDMS) film...
September 25, 2018: ACS Nano
https://www.readbyqxmd.com/read/30198262/ga-3-doping-induced-simultaneous-size-shape-control-enhanced-red-upconversion-luminescence-and-improved-x-ray-imaging-of-zno-yb-tm-for-multifunctional-nanoprobes
#12
Yuemei Li, Rui Wang, Wei Zheng, Yongmei Li
We report that the efficient Ga3+ -doped ZnO:Yb/Tm (7/0.5 mol %) upconversion nanoparticles (UCNPs) can simultaneously control size/shape and enhance red upconversion luminescence (UCL) by transition-metal Ga3+ doping. The dynamic decay time reveals that the intensity of red upconversion luminescence increases with increasing Ga3+ content. Furthermore, upconversion nanoparticles are fabricated through silica layer with Stöber method. The lung of mouse with the ZnO:Ga/Yb/Tm@SiO2 injection can be readily visualized using X-ray imaging, which will influence the field of biological probe based on UCNPs@SiO2 ...
October 1, 2018: Inorganic Chemistry
https://www.readbyqxmd.com/read/30194234/radioactive-90-y-upconversion-nanoparticles-conjugated-with-recombinant-targeted-toxin-for-synergistic-nanotheranostics-of-cancer
#13
Evgenii L Guryev, Natalia O Volodina, Natalia Y Shilyagina, Sergey V Gudkov, Irina V Balalaeva, Arthur B Volovetskiy, Alexander V Lyubeshkin, Alexey V Sen', Sergey A Ermilov, Vladimir A Vodeneev, Rem V Petrov, Andrei V Zvyagin, Zhores I Alferov, Sergey M Deyev
We report combined therapy using upconversion nanoparticles (UCNP) coupled to two therapeutic agents: beta-emitting radionuclide yttrium-90 (90 Y) fractionally substituting yttrium in UCNP, and a fragment of the exotoxin A derived from Pseudomonas aeruginosa genetically fused with a targeting designed ankyrin repeat protein (DARPin) specific to HER2 receptors. The resultant hybrid complex UCNP-R-T was tested using human breast adenocarcinoma cells SK-BR-3 overexpressing HER2 receptors and immunodeficient mice, bearing HER2-positive xenograft tumors...
September 25, 2018: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/30189939/synthesis-of-lanthanide-ion-doped-nayf%C3%A2-rgb-up-conversion-nanoparticles-for-anti-counterfeiting-application
#14
Guo Gong, Shaowen Xie, Ya Song, Haihu Tan, Jianxiong Xu, Changfan Zhang, Lijian Xu
Well-defined and mono-dispersed lanthanide-ion-doped NaYF4 up-conversion nanoparticles (UCNPs) were synthesized via thermal decomposition using lanthanide oleate as the precursor. By rational selecting the dopant pairs of the doped lanthanide ions (Y3+, Yb3+, Er3+ and Tm3+) with accurate molar ratios, three-primary-color (RGB) UCNPs which exhibited green (UCNPs-G), blue (UCNPs-B) and red (UCNPs-R) fluorescence, respectively, were prepared. The X-ray diffraction (XRD) patterns showed that the three UCNPs were purely hexagonal-phase NaYF4 crystals...
December 1, 2018: Journal of Nanoscience and Nanotechnology
https://www.readbyqxmd.com/read/30177988/construction-of-a-targeted-photodynamic-nanotheranostic-agent-using-upconversion-nanoparticles-coated-with-an-ultrathin-silica-layer
#15
Zihong Yue, Tongtong Hong, Xinyue Song, Zonghua Wang
Two-activator codoped UCNPs served as energy donors and photosensitizers entrapped in an ultrathin silica layer served as energy acceptors to establish LRET-based photodynamic therapy with the advantages of shortened donor-to-acceptor distance and enhanced LRET efficiency. The exterior PEG-FA ligand further enhanced the biocompatibility and targetability to cancer cells and the tumor section.
September 25, 2018: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/30174065/detection-of-choline-and-hydrogen-peroxide-in-infant-formula-milk-powder-with-near-infrared-upconverting-luminescent-nanoparticles
#16
Ling Zhang, Shuhan Yin, Jiaze Hou, Wenping Zhang, Hui Huang, Yongxin Li, Cong Yu
Choline is an essential nutrient for the growth and development of the baby, and therefore it is often added to infant formula. In this paper, a novel sensor for choline determination in infant formula is developed based on upconverting nanoparticles (UCNPs) with near infrared luminescence. UCNPs-based detection can avoid the interference of background fluorescence from complex samples, and thus provide high selectivity and sensitivity. It was observed that in the presence of Fe3+ , polyacrylic acid coated UCNPs were quenched to 3% of its original intensity...
January 1, 2019: Food Chemistry
https://www.readbyqxmd.com/read/30151518/elimination-of-concentration-dependent-luminescence-quenching-in-surface-protected-upconversion-nanoparticles
#17
Xiang Zheng, Swati Shikha, Yong Zhang
Quenching of lanthanide-doped upconversion nanoparticle (UCNP) luminescence at high dopant concentrations is an existing challenge that hampers their desired applications. It has already been reported that concentration quenching is strongly coupled to surface quenching. However, in this study we found that surface quenching is not the only cause for concentration quenching and concentration quenching was still observed in UCNPs with a well-protected surface. By using a mathematical model to better understand the processes, we proposed that this concentration quenching could be minimized by moving the extra sensitizers (Yb3+) to a different layer...
September 13, 2018: Nanoscale
https://www.readbyqxmd.com/read/30141108/turn-on-fluorometric-immunosensor-for-diethylstilbestrol-based-on-the-use-of-air-stable-polydopamine-functionalized-black-phosphorus-and-upconversion-nanoparticles
#18
Shuyue Ren, Ye Li, Qiyue Guo, Yuan Peng, Jialei Bai, Baoan Ning, Zhixian Gao
The preparation of air-stable black phosphorus (BP) is challenging because atomic layers of BP degrade rapidly on exposure to oxygen. A strategy is presented for the synthesis of BP functionalized with polydopamine (PDA/BP). Dopamine was self-polymerized to yield polydopamine (PDA) which then was used to coat the surface of BP. PDA can be easily reduced and this prevents BP degradation. PDA/BP also is a viable matrix for the adsorption of proteins due to the presence of functional groups. Without any chemical activation, diethylstilbestrol (DES)-specific monoclonal antibody was adsorbed on the PDA/BP surface...
August 23, 2018: Mikrochimica Acta
https://www.readbyqxmd.com/read/30120242/multi-photon-near-infrared-emission-saturation-nanoscopy-using-upconversion-nanoparticles
#19
Chaohao Chen, Fan Wang, Shihui Wen, Qian Peter Su, Mike C L Wu, Yongtao Liu, Baoming Wang, Du Li, Xuchen Shan, Mehran Kianinia, Igor Aharonovich, Milos Toth, Shaun P Jackson, Peng Xi, Dayong Jin
Multiphoton fluorescence microscopy (MPM), using near infrared excitation light, provides increased penetration depth, decreased detection background, and reduced phototoxicity. Using stimulated emission depletion (STED) approach, MPM can bypass the diffraction limitation, but it requires both spatial alignment and temporal synchronization of high power (femtosecond) lasers, which is limited by the inefficiency of the probes. Here, we report that upconversion nanoparticles (UCNPs) can unlock a new mode of near-infrared emission saturation (NIRES) nanoscopy for deep tissue super-resolution imaging with excitation intensity several orders of magnitude lower than that required by conventional MPM dyes...
August 17, 2018: Nature Communications
https://www.readbyqxmd.com/read/30113851/seeing-targeting-and-delivering-with-upconverting-nanoparticles
#20
Ghulam Jalani, Vivienne Tam, Fiorenzo Vetrone, Marta Cerruti
Efficient control over drug release is critical to increasing drug efficacy and avoiding side effects. An ideal drug delivery system would deliver drugs in the right amount, at the right location and at the right time noninvasively. This can be achieved using light-triggered delivery: light is noninvasive, spatially precise and safe if appropriate wavelengths are chosen. However, the use of light-controlled delivery systems has been limited to areas that are not too deep inside the body because ultraviolet (UV) or visible (Vis) light, the typical wavelengths used for photoreactions, have limited penetration and are toxic to biological tissues...
September 5, 2018: Journal of the American Chemical Society
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