scholarly journals Upconversion Nanoparticles Encapsulated with Amorphous Silica and Their Emission Quenching by FRET: A Nanosensor Excited by NIR for Mercury Detection

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 104
Author(s):  
Wei Wu ◽  
Wei Wei ◽  
Dingli Xu ◽  
Yunpeng Liu ◽  
Jin Li ◽  
...  
Keyword(s):  
Composite System ◽  
Near Infrared ◽  
Covalent Bond ◽  
High Energy ◽  
Deep Penetration ◽  
High Signal ◽  
Upconversion Nanoparticles ◽  
Energy Excitation ◽  
Excitation Light ◽  
Emission Quenching

Near-infrared (NIR) region has been considered as a diagnostic window since it avoids sample autofluorescence and light scattering. Upconversion nanoparticles (UCNPs) convert NIR light into high energy excitation light, making them a suitable excitation source for nanoprobes with deep penetration depth and high signal-to-noise ratio. The current work reported a rhodamine-derived probe for the detection of Hg(II). Corresponding absorption and emission responses for Hg(II) and detailed recognizing mechanism were discussed. An absorption titration experiment was performed. It was found that Hg(II) directly bonded with probe with chemical stoichiometry of 1:1, its association constant was calculated as 2.59 × 105 M−1. Such a high value indicated a direct coordination affinity between Hg(II) and this rhodamine-derived probe. Most metal cations exerted no increasing effect on the probe emission or absorption, exhibiting good sensing selectivity of probe towards Hg(II). Upconversion nanoparticles (UCNPs) were firstly encapsulated with silica (SiO2) and then bonded with the probe via a covalent bond. Given a near-infrared (NIR) laser excitation with wavelength of 980 nm, this probe, (E)-2-((3′,6′-bis(diethylamino)-2′,7′-dimethyl-3-oxospiro[isoindoline-1,9′-xanthen]-2-yl)imino)acetaldehyde (denoted as RHO), captured the energy of UCNPs via a FRET (fluorescence resonance energy transfer) path, resulting in the emission quenching of UCNPs. This composite system showed linear sensing behavior towards Hg(II) with high selectivity, which was similar to the case of pure probe. No probe emission, however, was observed from the composite system, which was different from the case of most literature reports. The self-quenching between probe molecules was claimed responsible for the probe emission, which was confirmed by experiment result and analysis. To the best of our knowledge, this is the first demonstration of covalently integrating SiO2-coated UCNPs with a rhodamine-derived probe for Hg(II) sensing.

Near-infrared light-controlled circularly polarized luminescence of self-organized emissive helical superstructures assisted by upconversion nanoparticles

2020 ◽  
Vol 56 (88) ◽  
pp. 13649-13652 ◽  
Author(s):  
Ao Juan ◽  
Hao Sun ◽  
Jinghui Qiao ◽  
Jinbao Guo
Keyword(s):  
Near Infrared ◽  
Infrared Light ◽  
Upconversion Nanoparticles ◽  
Near Infrared Light ◽  
Excitation Light ◽  
Circularly Polarized ◽  
Self Organized ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence ◽  
First Time

The reversible switching of circularly polarized luminescence in a self-organized emissive helical superstructure using 980 nm NIR excitation light with different power intensities is reported for the first time.

scholarly journals Upconversion Nanoparticles Decorated with Polysialic Acid for Solid Tumors Visualization In Vivo

2021 ◽  
Author(s):  
P. A. Demina ◽  
N. V. Sholina ◽  
R. A. Akasov ◽  
D. A. Khochenkov ◽  
A. V. Nechaev ◽  
...  
Keyword(s):  
Solid Tumors ◽  
Near Infrared ◽  
Signal To Noise Ratio ◽  
Polysialic Acid ◽  
Lymphatic Drainage ◽  
Circulation Time ◽  
High Signal ◽  
Upconversion Nanoparticles ◽  
Nonspecific Protein Adsorption

Abstract Upconversion nanoparticles (UCNPs) are a promising nanoplatform for bioreagent formation for in vivo imaging, which emit UV and blue light under the action of near-infrared radiation, providing deep tissue penetration and maintaining a high signal-to-noise ratio. In the case of solid tumor visualization, the UCNP surface functionalization is required to ensure a long circulation time, biocompatibility, and non-toxicity. The effective UCNP accumulation in the solid tumors is determined by the disturbed architecture of the vascular network and lymphatic drainage. This work demonstrates an approach to the UCNP biofunctionalization with endogenous polysialic acid for in vivo bioreagent formation. Bioreagents possess a low level of nonspecific protein adsorption and macrophage uptake, which allow the prolongation of the circulation time in the bloodstream up to 3 h. This leads to an intense photoluminescent signal in the tumor.

scholarly journals PAA Modified Upconversion Nanoparticles for Highly Selective and Sensitive Detection of Cu2+ Ions

2021 ◽  
Vol 8 ◽  
Author(s):  
Shaoshan Su ◽  
Zhurong Mo ◽  
Guizhen Tan ◽  
Hongli Wen ◽  
Xiang Chen ◽  
...  
Keyword(s):  
Near Infrared ◽  
Upconversion Emission ◽  
Upconversion Nanoparticles ◽  
Highly Sensitive ◽  
Carboxylate Complex ◽  
Sensitivity And Selectivity ◽  
Uv Visible ◽  
Emission Quenching ◽  
Co Precipitation ◽  
Higher Sensitivity

Detection of the Cu2+ ions is crucial because of its environmental and biological implications. The fluorescent-based organic sensors are not suitable for Cu2+ detection due to their short penetration depth caused by the UV/visible excitation source. Therefore, we have demonstrated a highly sensitive and selective near-infrared (NIR) excitable poly(acrylic acid) (PAA) coated upconversion nanoparticles (UCNPs) based sensor for Cu2+ detection. We construct the PAA modified Na(Yb, Nd)F4@Na(Yb, Gd)F4:Tm@NaGdF4 core-shell-shell structured UCNPs based sensor via a co-precipitation route. The upconversion emission intensity of the PAA-UCNPs decreases linearly with the increase in the Cu2+ concentration from 0.125 to 3.125 μM due to the copper carboxylate complex formation between Cu2+ and PAA-UCNPs. The calculated detection limit of the PAA-UCNPs based sensor is 0.1 μM. The PAA-UCNPs based sensor is very sensitive and selective toward detecting the Cu2+ ions, even when the Cu2+ co-exist with other metal ions. The EDTA addition has significantly reversed the upconversion emission quenching by forming the EDTA-Cu2+ complex based on their greater affinity toward the Cu2+. Therefore, the PAA-UCNPs based sensor can be a promising candidate for Cu2+ detection because of their higher sensitivity and selectivity under 980 nm NIR excitation.

scholarly journals Recent Advances of Upconversion Nanomaterials in the Biological Field

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2474
Author(s):  
Cunjin Gao ◽  
Pengrui Zheng ◽  
Quanxiao Liu ◽  
Shuang Han ◽  
Dongli Li ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Near Infrared ◽  
Upconversion Luminescence ◽  
Chemical Properties ◽  
Biological Tissues ◽  
High Energy ◽  
Research Progress ◽  
High Signal ◽  
Bio Imaging ◽  
Anti Stokes

Rare Earth Upconversion nanoparticles (UCNPs) are a type of material that emits high-energy photons by absorbing two or more low-energy photons caused by the anti-stokes process. It can emit ultraviolet (UV) visible light or near-infrared (NIR) luminescence upon NIR light excitation. Due to its excellent physical and chemical properties, including exceptional optical stability, narrow emission band, enormous Anti-Stokes spectral shift, high light penetration in biological tissues, long luminescent lifetime, and a high signal-to-noise ratio, it shows a prodigious application potential for bio-imaging and photodynamic therapy. This paper will briefly introduce the physical mechanism of upconversion luminescence (UCL) and focus on their research progress and achievements in bio-imaging, bio-detection, and photodynamic therapy.

scholarly journals MEASUREMENTS OF PRESSURE DISTRIBUTIONS ON A ROTOR BLADE USING PSP TECHNIQUES

2011 ◽  
Vol 12 (3) ◽  
Author(s):  
Kidong Kim ◽  
Kijung Kwon
Keyword(s):  
Rotor Blade ◽  
Pressure Fluctuations ◽  
Aerodynamic Characteristics ◽  
High Energy ◽  
Small Scale ◽  
Pressure Sensitive Paint ◽  
Energy Excitation ◽  
Excitation Light ◽  
Pressure Distributions ◽  
Pressure Sensitive

Surface pressure distributions on a rotating blade were measured by using pressure sensitive paint (PSP) to understand aerodynamic characteristics of a rotor blade. The present study was conducted to investigate the PSP techniques for measuring the pressure distributions on a rotor blade. In order to perform the experiment, the PSP was required to response very fast due to rapid pressure fluctuations on a rotor blade. High energy excitation light source was also needed to acquire proper intensity images in a short excitation time. The techniques were based on a lifetime method. Qualitative pressure distributions on an upper surface of small scale rotor in hovering condition were measured as a preliminary experiment prior to forward flight conditions in the KARI low speed wind tunnel laboratory. From measured pressure distributions, striking pressure gradient was observed on an upper surface of rotor blade and the resulting pressure showed expected gradient depending on different collective pitch angles. ABSTRAK : Pengagihan tekanan permukaan ke atas berbilah putar disukat menggunakan cat sensitive tekanan (pressure sensitive paint (PSP)) untuk memahami sifat-sifat aerodinamik suatu berbilah putar. Kajian telah dijalankan untuk menyelidik teknik-teknik PSP dengan mengukur agihan tekanan ke atas suatu berbilah putar. Agar eksperimen dapat dijalankan dengan baik, PSP harus bertindak cepat kerana tekanan naik turun dengan pantas ke atas berbilah putar. Sumber cahaya ujaan tenaga tinggi diperlukan untuk mendapatkan imej keamatan wajar dalam jangka masa ujaan yang pendek. Teknik-teknik tersebut terhasil daripada kajian semasa hayat. Agihan tekanan kualitatif ke permukaan atas berskala kecil pemutar dalam keadaan mengapung diukur sebagai permulaan eksperimen, sebelum penerbangan kehadapan dalam makmal terowong angin laju rendah KARI. Daripada agihan tekanan yang disukat, kecerunan tekanan yang ketara diperolehi daripada permerhatian terhadap permukaan atas berbilah putar dan tekanan yang didapati menunjukkan tekanan kecerunan yang dijangka, bergantung kepada sudut himpunan anggul yang berbeza.

Upconversion nanocomposites for photo-based cancer theranostics

2016 ◽  
Vol 4 (32) ◽  
pp. 5331-5348 ◽  
Author(s):  
Shuailiang Wang ◽  
Anyao Bi ◽  
Wenbin Zeng ◽  
Zhen Cheng
Keyword(s):  
Penetration Depth ◽  
High Energy ◽  
Upconversion Nanoparticles ◽  
Tissue Penetration ◽  
Excitation Light ◽  
Long Wavelength ◽  
Photochemical Properties ◽  
Cancer Theranostics ◽  
Significant Attention

Upconversion nanoparticles (UCNPs) are able to convert long wavelength excitation light into high energy ultraviolet (UV) or visible emissions, and they have attracted significant attention because of their distinct photochemical properties including sharp emission bands, low autofluorescence, high tissue penetration depth and minimal photodamage to tissues.

scholarly journals Optoelectronic Sensory System for Raman Spectromicroscopes

2021 ◽  
Vol 6 (1) ◽  
pp. 87
Author(s):  
Gheorghe Gutt ◽  
Valentin Popa ◽  
Mihai Dimian
Keyword(s):  
Microscopic Study ◽  
Spectral Resolution ◽  
Near Infrared ◽  
Focal Point ◽  
High Energy ◽  
Peak Height ◽  
High Energy Density ◽  
Spectrometric Analysis ◽  
Technical Solution ◽  
Excitation Light

In order to obtain a high microscopic and spectral resolution, both for the microscopic study and for the spectrometric analysis carried out simultaneously at the same area of the sample, an adaptive optoelectronic system for Raman spectromicroscopes with a near-infrared excitation light source is designed. The current system and its working mode have a major disadvantage due to the fact that the sample is moved several times to and from the focusing lens of the excitation radiation in the search for the focal point in order to ensure the maximum spectral resolution. In this process, the peak height for the Stokes spectrum is monitored and the focal point is considered achieved when the peak height reaches its maximum. Due to the high energy density in a focal point, repeated searches of this point may lead to the modification of the chemical composition of the investigated material and, in some cases, even to the decomposition of some of its components. This paper presents an advanced technical solution that allows the microscopic study of the sample in the focal point of the visible spectrum, as well as the rapid and automatic search of the focal point in the Raman spectral analysis, at a wavelength of 1064 nm in the near-infrared spectral domain without thermally affecting the sample.

Platform of near-infrared light-induced reversible deactivation radical polymerization: upconversion nanoparticles as internal light sources

2016 ◽  
Vol 7 (48) ◽  
pp. 7370-7374 ◽  
Author(s):  
Chunlai Ding ◽  
Jie Wang ◽  
Wei Zhang ◽  
Xiangqiang Pan ◽  
Zhengbiao Zhang ◽  
...  
Keyword(s):  
Radical Polymerization ◽  
Near Infrared ◽  
Infrared Light ◽  
Deep Penetration ◽  
Upconversion Nanoparticles ◽  
Light Sources ◽  
Near Infrared Light ◽  
Reversible Deactivation ◽  
Reversible Deactivation Radical Polymerization

The use of a 980 nm light providing deep penetration power and high compatibility for weak bonds shows potential for bio-related applications.

Construction of a near-infrared responsive upconversion nanoplatform against hypoxic tumors via NO-enhanced photodynamic therapy

Nanoscale ◽  
2020 ◽  
Vol 12 (14) ◽  
pp. 7875-7887 ◽  
Author(s):  
Ying Lan ◽  
Xiaohui Zhu ◽  
Ming Tang ◽  
Yihan Wu ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Near Infrared ◽  
Upconversion Nanoparticles

A near-infrared (NIR) activated theranostic nanoplatform based on upconversion nanoparticles (UCNPs) is developed in order to overcome the hypoxia-associated resistance in photodynamic therapy by photo-release of NO upon NIR illumination.

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