scholarly journals Upconversion Nanoparticles Encapsulated with Molecularly Imprinted Amphiphilic Copolymer as a Fluorescent Probe for Specific Biorecognition

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3522
Author(s):  
Hsiu-Wen Chien ◽  
Chien-Hsin Yang ◽  
Yan-Tai Shih ◽  
Tzong-Liu Wang
Keyword(s):  
Fluorescent Probe ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Random Copolymer ◽  
Random Copolymers ◽  
Upconversion Nanoparticles ◽  
Amphiphilic Copolymers ◽  
Molecularly Imprinted ◽  
Light Region ◽  
Copolymer Poly

A fluorescent probe for specific biorecognition was prepared by a facile method in which amphiphilic random copolymers were encapsulated with hydrophobic upconversion nanoparticles (UCNPs). This method quickly converted the hydrophobic UCNPs to hydrophilic UNCPs. Moreover, the self-folding ability of the amphiphilic copolymers allowed the formation of molecular imprinting polymers with template-shaped cavities. LiYF4:Yb3+/Tm3+@LiYF4:Yb3+ UCNP with up-conversion emission in the visible light region was prepared; this step was followed by the synthesis of an amphiphilic random copolymer, poly(methacrylate acid-co-octadecene) (poly(MAA-co-OD)). Combining the UCNPs and poly(MAA-co-OD) with the templates afforded a micelle-like structure. After removing the templates, UCNPs encapsulated with the molecularly imprinted polymer (MIP) (UCNPs@MIP) were obtained. The adsorption capacities of UCNPs@MIP bound with albumin and hemoglobin, respectively, were compared. The results showed that albumin was more easily bound to UCNPs@MIP than to hemoglobin because of the effect of protein conformation. The feasibility of using UCNPs@MIP as a fluorescent probe was also studied. The results showed that the fluorescence was quenched when hemoglobin was adsorbed on UCNPs@MIP; however, this was not observed for albumin. This fluorescence quenching is attributed to Förster resonance energy transfer (FRET) and overlap of the absorption spectrum of hemoglobin with the fluorescence spectrum of UCNPs@MIP. To our knowledge, the encapsulation approach for fabricating the UCNPs@MIP nanocomposite, which was further used as a fluorescent probe, might be the first report on specific biorecognition.

scholarly journals Nanoscale optical writing through upconversion resonance energy transfer

2021 ◽  
Vol 7 (9) ◽  
pp. eabe2209
Author(s):  
S. Lamon ◽  
Y. Wu ◽  
Q. Zhang ◽  
X. Liu ◽  
M. Gu
Keyword(s):  
Graphene Oxide ◽  
Energy Transfer ◽  
Energy Consumption ◽  
Data Storage ◽  
High Capacity ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
High Energy ◽  
Optical Data ◽  
Upconversion Nanoparticles

Nanoscale optical writing using far-field super-resolution methods provides an unprecedented approach for high-capacity data storage. However, current nanoscale optical writing methods typically rely on photoinitiation and photoinhibition with high beam intensity, high energy consumption, and short device life span. We demonstrate a simple and broadly applicable method based on resonance energy transfer from lanthanide-doped upconversion nanoparticles to graphene oxide for nanoscale optical writing. The transfer of high-energy quanta from upconversion nanoparticles induces a localized chemical reduction in graphene oxide flakes for optical writing, with a lateral feature size of ~50 nm (1/20th of the wavelength) under an inhibition intensity of 11.25 MW cm−2. Upconversion resonance energy transfer may enable next-generation optical data storage with high capacity and low energy consumption, while offering a powerful tool for energy-efficient nanofabrication of flexible electronic devices.

scholarly journals Contribution of resonance energy transfer to the luminescence quenching of upconversion nanoparticles with graphene oxide

2020 ◽  
Vol 575 ◽  
pp. 119-129 ◽  
Author(s):  
Diego Mendez-Gonzalez ◽  
Oscar G. Calderón ◽  
Sonia Melle ◽  
Jesús González-Izquierdo ◽  
Luis Bañares ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Energy Transfer ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Luminescence Quenching ◽  
Upconversion Nanoparticles

scholarly journals A Near-Infrared Fluorescent Probe Based on a FRET Rhodamine Donor Linked to a Cyanine Acceptor for Sensitive Detection of Intracellular pH Alternations

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2679 ◽  
Author(s):  
Yibin Zhang ◽  
Jianheng Bi ◽  
Shuai Xia ◽  
Wafa Mazi ◽  
Shulin Wan ◽  
...  
Keyword(s):  
Fluorescent Probe ◽  
Intracellular Ph ◽  
Near Infrared ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Sensitive Detection ◽  
Solution Ph ◽  
Acidic Conditions ◽  
Ph Level ◽  
Rhodamine Dye

A fluorescence resonance energy transfer (FRET)-based near-infrared fluorescent probe (B+) for double-checked sensitive detection of intracellular pH changes has been synthesized by binding a near-infrared rhodamine donor to a near-infrared cyanine acceptor through robust C-N bonds via a nucleophilic substitution reaction. To demonstrate the double-checked advantages of probe B+, a near-infrared probe (A) was also prepared by modification of a near-infrared rhodamine dye with ethylenediamine to produce a closed spirolactam residue. Under basic conditions, probe B+ shows only weak fluorescence from the cyanine acceptor while probe A displays nonfluorescence due to retention of the closed spirolactam form of the rhodamine moiety. Upon decrease in solution pH level, probe B+ exhibits a gradual fluorescence increase from rhodamine and cyanine constituents at 623 nm and 743 nm respectively, whereas probe A displays fluorescence increase at 623 nm on the rhodamine moiety as acidic conditions leads to the rupture of the probe spirolactam rings. Probes A and B+ have successfully been used to monitor intracellular pH alternations and possess pKa values of 5.15 and 7.80, respectively.

scholarly journals Closing and opening of the RNA polymerase trigger loop

2019 ◽  
Author(s):  
Abhishek Mazumder ◽  
Miaoxin Lin ◽  
Achillefs N. Kapanidis ◽  
Richard H. Ebright
Keyword(s):  
Rna Polymerase ◽  
Fluorescent Probe ◽  
Active Center ◽  
Single Molecule ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Single Molecule Fluorescence ◽  
Structural Element ◽  
Trigger Loop ◽  
Nucleotide Addition

The RNA polymerase (RNAP) trigger loop (TL) is a mobile structural element of the RNAP active center that, based on crystal structures, has been proposed to cycle between an “unfolded”/“open” state that allows an NTP substrate to enter the active center and a “folded”/“closed” state that holds the NTP substrate in the active center. Here, by quantifying single-molecule fluorescence resonance energy transfer between a first fluorescent probe in the TL and a second fluorescent probe elsewhere in RNAP or in DNA, we detect and characterize TL closing and opening in solution. We show that the TL closes and opens on the millisecond timescale; we show that TL closing and opening provides a checkpoint for NTP complementarity, NTP ribo/deoxyribo identity, and NTP tri/di/monophosphate identity, and serves as a target for inhibitors; and we show that one cycle of TL closing and opening typically occurs in each nucleotide addition cycle in transcription elongation.

Aptamer-modified sensitive nanobiosensors for the specific detection of antibiotics

2020 ◽  
Vol 8 (37) ◽  
pp. 8607-8613
Author(s):  
Ying Zhang ◽  
Bo Duan ◽  
Qing Bao ◽  
Tao Yang ◽  
Tiancheng Wei ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Energy Transfer ◽  
Fluorescence Resonance Energy Transfer ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Upconversion Nanoparticles ◽  
Core Shell ◽  
Specific Detection ◽  
Energy Donor ◽  
Energy Acceptor

A highly selective, fluorescence resonance energy transfer (FRET) based aptasensor for enrofloxacin (ENR) detection was developed using core–shell upconversion nanoparticles as an energy donor and graphene oxide as an energy acceptor.

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