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Shuai Zha, Yan Ho Fung, Ho-Fai Chau, Ping'an Ma, Jun Lin, Jing Wang, Lai Sheung Chan, Guang Zhu, Hong Lok Lung, Ka-Leung Wong
Non-responsive emission enhancement is the disadvantage of upconversion nanomaterials (UCNM) when compared with conventional organic based agents for molecular imaging. We herein show a new strategy by conjugating NaGdF4:Yb3+,Er3+@NaGdF4 (UCNP) with peptides to achieve responsive UC emission enhancement upon binding to a targeted protein - EBNA1. EBNA1 is a well-known viral latent protein for the EBV-associated cancer. Peptide-coating of the functionalized core-shell nanoparticle diminishes upconverted emission intensity drastically...
August 9, 2018: Nanoscale
Bining Tian, Angel Fernandez-Bravo, Hossein Najafiaghdam, Nicole A Torquato, M Virginia P Altoe, Ayelet Teitelboim, Cheryl A Tajon, Yue Tian, Nicholas J Borys, Edward S Barnard, Mekhail Anwar, Emory M Chan, P James Schuck, Bruce E Cohen
Multiphoton imaging techniques that convert low-energy excitation to higher energy emission are widely used to improve signal over background, reduce scatter, and limit photodamage. Lanthanide-doped upconverting nanoparticles (UCNPs) are among the most efficient multiphoton probes, but even UCNPs with optimized lanthanide dopant levels require laser intensities that may be problematic. Here, we develop protein-sized, alloyed UCNPs (aUCNPs) that can be imaged individually at laser intensities >300-fold lower than needed for comparably sized doped UCNPs...
August 6, 2018: Nature Communications
Bin Xue, Dan Wang, Langping Tu, Dapeng Sun, Pengtao Jing, Yulei Chang, Youlin Zhang, Xiaomin Liu, Jing Zuo, Jun Song, Junle Qu, Evert Jan Meijer, Hong Zhang, Xianggui Kong
Dye sensitization is becoming a new dimension to highly improve the upconversion luminescence (UCL) of lanthanide-doped upconversion nanoparticles (UCNPs). However, there is still a lack of general understanding of the dye-UCNPs interactions, especially the confused large mismatch between the inputs and outputs. By taking dye-sensitized NaYF4 :Yb/Er@NaYF4 :Nd UCNPs as a model system, we not only revealed the in-depth energy-dissipative process for dye-sensitized UCL but also confirmed the first ever experimental observation of the energy back transfer (EBT) in the dye-sensitized UCL...
August 2, 2018: Journal of Physical Chemistry Letters
Kumbam Lingeshwar Reddy, Ramachandran Balaji, Ashish Kumar, Venkata Krishnan
Near infrared (NIR) light utilization in a range of current technologies has gained huge significance due to its abundance in nature and nondestructive properties. NIR active lanthanide (Ln) doped upconversion nanomaterials synthesized in controlled shape, size, and surface functionality can be combined with various pertinent materials for extensive applications in diverse fields. Upconversion nanophosphors (UCNP) possess unique abilities, such as deep tissue penetration, enhanced photostability, low toxicity, sharp emission peaks, long anti-Stokes shift, etc...
July 31, 2018: Small
Eduardo D Martínez, Ricardo R Urbano, Carlos Rettori
Plasmon enhancement of luminescence is a common strategy to boost the efficiency of both fluorescence and upconversion via the augmented local electromagnetic field. However, the local heating produced when exciting the plasmon resonance of metallic nanoparticles is often overlooked. As higher temperatures are usually detrimental for radiative processes, only the electromagnetic contribution is exploited for enhancement. We show here that for small size (<20 nm) rare-earth doped β-NaGd(Y)F4 upconversion nanoparticles (UCNPs), the photothermal properties of gold nanostars (AuNSs) can be used to enhance the total emission intensity...
July 24, 2018: Nanoscale
Yu Wang, Jialei Bai, Bingyang Huo, Shuai Yuan, Man Zhang, Xuan Sun, Yuan Peng, Shuang Li, Jiang Wang, Baoan Ning, Zhixian Gao
A novel upconversion fluorescent aptasensor based on hybridization chain reaction and nicking endonuclease has been developed for detection of polychlorinated biphenyls (PCBs). It combined the dual advantages of UCNPs and HCR. Two harpins (H1 and H2) were first designed according to the partial complementary sequence (cDNA) of the PCB72/106. Since the aptamer specifically recognized the target, the cDNA was detached from the magnetic microspheres (MMPs). The cDNA could initiate hybridization chain reaction (HCR) and open the stems of H1 and H2...
August 3, 2018: Analytical Chemistry
Lidija Mancic, Aleksandra Djukic-Vukovic, Ivana Dinic, Marko G Nikolic, Mihailo D Rabasovic, Aleksandar J Krmpot, Antonio M L M Costa, Dijana Trisic, Milos Lazarevic, Ljiljana Mojovic, Olivera Milosevic
Lanthanide-doped fluoride up-converting nanoparticles (UCNPs) represent the new class of imaging contrast agents which hold great potential for overcoming existing problems associated with traditionally used dyes, proteins and quantum dots. In this study, a new kind of hybrid NaYF4 :Yb,Er/PLGA nanoparticles for efficient biolabeling were prepared through one-pot solvothermal synthesis route. Morphological and structural characteristics of the as-designed particles were obtained using X-ray powder diffraction (XRPD), scanning and transmission electron microscopy (SEM/TEM), energy dispersive spectroscopy (EDS), Fourier transform infrared (FTIR) and photoluminescence (PL) spectroscopy, while their cytotoxicity as well as up-conversion (UC) labeling capability were tested in vitro toward human gingival cells (HGC) and oral squamous cell carcinoma (OSCC)...
October 1, 2018: Materials Science & Engineering. C, Materials for Biological Applications
Zhi Du, Nan Gao, Xiaohui Wang, Jinsong Ren, Xiaogang Qu
C60 has a special dual function; it can act as both a powerful reactive oxygen species (ROS) producer under UV or visible light and an ROS scavenger in the dark. However, ROS has double-edged effects in living systems. It is still a great challenge for biomedical application to switch and adjust the two opposite properties of C60 in one system. Herein, UCNP@C60 -pep (UCNP: upconversion nanoparticle, pep: Aβ-target peptide KLVFF) is designed as a near-infrared-switchable nanoplatform for synergy therapy of Alzheimer's disease (AD)...
July 20, 2018: Small
Tarek Sabri, Peter D Pawelek, John A Capobianco
A modified version of a desolvation method was used to render lanthanide-doped upconverting nanoparticles NaGdF4 :Yb3+ /Er3+ (Ln-UCNPs) water-dispersible and biocompatible for photodynamic therapy. Bovine serum albumin (BSA) was used as surface coating with a direct conjugation to NaGdF4 :Yb3+ /Er3+ nanoparticles forming a ∼2 nm thick shell. It was estimated that approximately 112 molecules of BSA were present and cross-linked per NaGdF4 :Yb3+ /Er3+ nanoparticle. Analysis of the BSA structural behavior on the Ln-UCNP surfaces displayed up to 80% loss of α-helical content...
August 6, 2018: ACS Applied Materials & Interfaces
Yung-Chieh Chan, Ming-Hsien Chan, Chieh-Wei Chen, Ru-Shi Liu, Michael Hsiao, Din Ping Tsai
The matrix metalloproteinases (MMPs) are well-known mediators that are activated in tumor progression. MMP2 is a kind of gelatinase in extracellular matrix remodeling and cancer metastasis processes. MMP2 secretion increased in many types of cancer diseases, and its abnormal expression is associated with a poor prognosis. We fabricated a nanocomposite that sensed MMP2 expression by a red and blue light change. This nanocomposite consisted of an upconversion nanoparticle (UCNP), MMP2-sensitive peptide, and CuInS2 /ZnS quantum dot (CIS/ZnS QD)...
February 28, 2018: ACS Omega
Ursula Stochaj, Diana C Rodríguez Burbano, Daniel R Cooper, Mohamed Kodiha, John A Capobianco
Lanthanide-doped upconverting nanoparticles (Ln-UCNPs) possess optical and physicochemical properties that are promising for the design of new theranostic platforms. This applies in particular to the treatment of cancer. Towards this goal, oleate-capped-NaLuF4:Tm3+(0.5%)/Yb3+(20%)/Gd3+(30%) with an average size of 35 nm ± 2 nm were synthesized by co-precipitation. Due to their hydrophobic surface, these Ln-UCNPs produced agglomerates under cell culture conditions. To assess the cellular response to Ln-UCNPs at the molecular level, we evaluated several key aspects of tumor cell physiology...
August 2, 2018: Nanoscale
Min Chen, Felix Y H Kutsanedzie, Wu Cheng, Akwasi Akomeah Agyekum, Huanhuan Li, Quansheng Chen
A system composed of upconversion nanoparticles (UCNPs) and N,N-diethyl-p-phenylenediamine (EPA) is shown to be a useful probe for highly sensitive and selective fluorometric determination of ferric ion. The fluorescence of the UCNPs (under the 980 nm excitation) has peaks at 546, 657, 758 and 812 nm. EPA is readily oxidized by Fe(III) to generate a dye with a peak at 552 nm. This causes an inner filter effect on the fluorescence peaks at 546 nm, whereas the emissions at 657, 758 and 812 nm remained unchanged...
July 17, 2018: Mikrochimica Acta
Xu Wang, Xiu-Ping Yan
Type I topoisomerases (TOPOI), a potential diagnostic biomarker and a target for chemotherapeutic agents, play essential roles in DNA replication, transcription, chromosome segregation, and recombination. It is essential to develop analytical methods for accurate detection of TOPOI in biological fluids for early diagnosis of diseases. Here we show an assay for TOPOI on the basis of the target-induced self-assembly of graphene oxide (GO) sheets onto hydroxycamptothecin-functionalized upconversion nanoparticles (HCPT-UCNPs)...
July 17, 2018: Analytical and Bioanalytical Chemistry
Sunan Cao, Zhi Li, Jinyuan Zhao, Mi Chen, Nan Ma
Optical sensing of cancer-relevant protease is of great value for cancer diagnostics, prognosis, and drug discovery. Multiplex sensing is known to improve predicative accuracy yet remains challenging because of severe fluorescence signal crosstalk in a single assay. Herein, we developed a multichannel optical sensor based on upconversion nanoparticles for multiplex ratiometric sensing of proteolytic activities of two matrix metalloproteinases (MMP-2 and MMP-7). To this end, we rationally designed a NaYF4 :Gd3+ /Yb3+ @NaYF4 :Yb3+ /Tm3+ /Er3+ core-shell structure that favors multicolor narrow-band emission of both Tm3+ and Er3+ dopants and efficient luminescence resonance energy transfer (LRET) between the dopants in the shell and the fluorophores on the particle surface...
July 31, 2018: ACS Sensors
Yuan Wu, Dan Li, Fang Zhou, Hao Liang, Yuan Liu, Weijia Hou, Quan Yuan, Xiaobing Zhang, Weihong Tan
We have developed a simple and versatile strategy for in situ growth of MnO2 on the surfaces of oleic acid-capped hydrophobic upconversion nanoparticles (UCNPs) by optimizing the component concentrations in the Lemieux-von Rudloff reagent. The oxidation time was shortened by a factor of two compared to that of the reported method. This oxidation process has no obvious adverse effects on the phases of UCNPs. STEM, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) and energy-dispersive X-ray analysis (EDX) characterization demonstrated the successful growth of MnO2 on the surfaces of UCNPs...
June 28, 2018: Chemical Science
Fangyuan Li, Yang Du, Jianan Liu, Heng Sun, Jin Wang, Ruiqing Li, Dokyoon Kim, Taeghwan Hyeon, Daishun Ling
Upconversion nanoparticle (UCNP)-mediated photodynamic therapy has shown great effectiveness in increasing the tissue-penetration depth of light to combat deep-seated tumors. However, the inevitable phototoxicity to normal tissues resulting from the lack of tumor selectivity remains as a major challenge. Here, the development of tumor-pH-sensitive photodynamic nanoagents (PPNs) comprised of self-assembled photosensitizers grafted pH-responsive polymeric ligands and UCNPs is reported. Under neutral pH conditions, photosensitizers aggregated in the PPNs are self-quenched; however, upon entry into a tumor microenvironment with lower pH, the PPNs not only exhibit enhanced tumor-cell internalization due to charge reversal but also are further disassembled into well-dispersed nanoparticles in the endo/lysosomes of tumor cells, enabling the efficient activation of photosensitizers...
July 12, 2018: Advanced Materials
Di Zhang, Lin Wei, Meile Zhong, Lehui Xiao, Hung-Wing Li, Jianfang Wang
The cellular uptake efficiency of nanostructures has been demonstrated to be highly dependent on the surface charge, size and shape although the cellular internalization process is still far from being well-understood. In this work, a series of NaYF4 :Yb3+ , Er3+ upconversion nanoparticles (UCNPs) with different morphologies and surface coatings were prepared to explore the influence of surface charge and morphology on the cellular internalization process with single-particle fluorescence microscopy. It is found that the higher the surface charge and larger the surface-to-volume ratio of the nanoparticles, the more efficient the cellular uptake will be...
June 21, 2018: Chemical Science
Yuxin Liu, Anqi Jiang, Qi Jia, Xuejiao Zhai, Lidong Liu, Liyi Ma, Jing Zhou
For many years, fluorosis has been known as a worldwide disease which seriously diminishes quality of life through skeletal embrittlement and hepatic damage. Aiming to develop novel drugs for simultaneous fluorosis diagnosis and therapy, in this work we explore the feasibility of a novel pyrogallic acid-titanium(iv) complex-modified upconversion nanoprobe (UCNP-PA-Ti) for F- capture and real-time quantification. Utilizing the strong interaction between Ti4+ and F- , the modified PA-Ti decomposes in F- -containing solution, which not only weakens the FRET but results in upconversion luminescence (UCL) recovery...
June 21, 2018: Chemical Science
Gibok Lee, Yong Il Park
Compared to traditional cancer treatments, drug/gene delivery is an advanced, safe, and efficient method. Nanoparticles are widely used as nanocarriers in a drug/gene delivery system due to their long circulation time and low multi-drug resistance. In particular, lanthanide-doped upconversion nanoparticles (UCNPs) that can emit UV and visible light by near-infrared (NIR) upconversion demonstrated more efficient and safer drug/gene delivery. Because of the low penetration depth of UV and visible light, a photoinduced reaction such as photocleavage or photoisomerization has proven restrictive...
July 9, 2018: Nanomaterials
Hong Ren, Zi Long, Xiaotong Shen, Ying Zhang, Jianghui Sun, Jin Ouyang, Na Na
An upconversion nanoparticle (UCNP)-based fluorescence resonance energy-transfer (FRET) strategy is normally restricted by the complicated preparations, low energy-transfer efficiency, and the challenge on improving specificity. Herein, simple DNA-functionalized UCNPs were designed as energy donors for constructing a FRET-based probe to detect the liver-specific microRNA 122 (miR-122). To improve FRET efficiency, UCNPs were constructed with confined core-shell structures, in which emitting ions were precisely located in the thin shell to make them close enough to external energy acceptors...
July 18, 2018: ACS Applied Materials & Interfaces
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