Water-Soluble Conjugated Polyelectrolytes with Molecular Bumper for Efficient FRET Biosensor

2006 ◽  
Vol 965 ◽  
Author(s):  
Han Young Woo ◽  
Doojin Vak ◽  
Guillermo C Bazan
Keyword(s):  
Photophysical Properties ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Structural Difference ◽  
Water Soluble ◽  
Conjugated Polyelectrolytes ◽  
Design Synthesis ◽  
Donor Acceptor ◽  
Thermodynamic Driving Force ◽  
Fret Efficiency

ABSTRACTWe report the design, synthesis and photophysical properties of two new water-soluble conjugated polyelectrolytes, poly(9,9'-bis(6-N,N,N-trimethylammoniumhexyl)fluorene-alt-1,4-(2,5-bis(6-N,N,N-trimethylammoniumhexyloxy))phenylene) tetrabromide (P1i) and poly((10,10'-bis(6-N,N,N-trimethylammoniumhexyl)-10H-spiro(anthracene-9,9'-fluorene))-alt-1,4-(2,5-bis(6-N,N,N-trimethylammoniumhexyloxy))phenylene) tetrabromide (P2i). They have same electronic conjugation but the main structural difference is the presence of the anthracenyl substituent orthogonal to the polymer main backbone in P2i. Fluorescence resonance energy transfer (FRET) from the two polymers as FRET donors to fluorescein-labeled single stranded DNA (ssDNA-Fl) was studied. It is observed the emission from ssDNA-Fl via FRET by excitation of P2i with a FRET efficiency of ∼60%. Fluorescein is not emissive within the ssDNA-Fl/P1i complex. We also observed clear PL quenching (Φ = 0.8 → Φ = 0.27) of fluorescein for P2i after electrostatic complexation with ssDNA-Fl. It suggests a quenching pathway of Fl emission through photo-induced charge transfer (PCT) in the electrostatic complex. Both P1i and P2i have same HOMO-LUMO electronic structures and a similar thermodynamic driving force for either FRET or PCT. It appears that PCT operates to a larger extent with P1i, proposing that the presence of the “molecular bumper” in P2i increases Fl emission by increasing the donor-acceptor distance, which decreases more acutely PCT quenching, relative to FRET.

Comparison of self-assembled and micelle encapsulated QD chemosensor constructs for biological sensing

2015 ◽  
Vol 185 ◽  
pp. 249-266 ◽  
Author(s):  
Christopher M. Lemon ◽  
Daniel G. Nocera
Keyword(s):  
Self Assembly ◽  
Metabolic Profiling ◽  
Photophysical Properties ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Core Shell ◽  
Biological Sensing ◽  
Two Photon ◽  
Photon Excitation ◽  
Fret Efficiency

Whereas a variety of covalent conjugation strategies have been utilized to prepare quantum dot (QD)-based nanosensors, supramolecular approaches of self-assembly have been underexplored. A major advantage of self-assembly is the ability to circumvent laborious synthetic efforts attendant to covalent conjugation of a chemosensor to functionalized QDs. Here, we combine a CdSe/ZnS core–shell QD with gold(iii) corroles using both self-assembly and micelle encapsulation to form QD nanosensors. Appreciable spectral overlap between QD emission and corrole absorption results in efficient Förster resonance energy transfer (FRET), which may be initiated by one- or two-photon excitation. The triplet state of the gold(iii) corroles is quenched by molecular oxygen, enabling these constructs to function as optical O2 sensors, which is useful for the metabolic profiling of tumours. The photophysical properties, including QD and corrole lifetimes, FRET efficiency, and O2 sensitivity, have been determined for each construct. The relative merits of each conjugation strategy are assessed with regard to their implementation as sensors.

scholarly journals Protein interaction quantified in vivo by spectrally resolved fluorescence resonance energy transfer

2004 ◽  
Vol 385 (1) ◽  
pp. 265-277 ◽  
Author(s):  
Valerică RAICU ◽  
David B. JANSMA ◽  
R. J. Dwayne MILLER ◽  
James D. FRIESEN
Keyword(s):  
Energy Transfer ◽  
Fluorescence Resonance Energy Transfer ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Receptor Protein ◽  
Acceptor Pair ◽  
Donor Acceptor ◽  
Fret Efficiency ◽  
Fluorescence Resonance

We describe a fluorescence resonance energy transfer (FRET)-based method for finding in living cells the fraction of a protein population (αT) forming complexes, and the average number (n) of those protein molecules in each complex. The method relies both on sensitized acceptor emission and on donor de-quenching (by photobleaching of the acceptor molecules), coupled with full spectral analysis of the differential fluorescence signature, in order to quantify the donor/acceptor energy transfer. The approach and sensitivity limits are well suited for in vivo microscopic investigations. This is demonstrated using a scanning laser confocal microscope to study complex formation of the sterile 2 α-factor receptor protein (Ste2p), labelled with green, cyan, and yellow fluorescent proteins (GFP, CFP, and YFP respectively), in budding yeast Saccharomyces cerevisiae. A theoretical model is presented that relates the efficiency of energy transfer in protein populations (the apparent FRET efficiency, Eapp) to the energy transferred in a single donor/acceptor pair (E, the true FRET efficiency). We determined E by using a new method that relies on Eapp measurements for two donor/acceptor pairs, Ste2p–CFP/Ste2p–YFP and Ste2p–GFP/Ste2p–YFP. From Eapp and E we determined αT≈1 and n≈2 for Ste2 proteins. Since the Ste2p complexes are formed in the absence of the ligand in our experiments, we conclude that the α-factor pheromone is not necessary for dimerization.

scholarly journals Energy Transfer in Dendritic Systems Having Pyrene Peripheral Groups as Donors and Different Acceptor Groups

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1062 ◽  
Author(s):  
Pasquale Porcu ◽  
Mireille Vonlanthen ◽  
Andrea Ruiu ◽  
Israel González-Méndez ◽  
Ernesto Rivera
Keyword(s):  
Energy Transfer ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Fullerene C60 ◽  
Energy Transfer Efficiency ◽  
Transfer Efficiency ◽  
Feature Article ◽  
Donor Acceptor ◽  
Fret Efficiency

In this feature article, a specific overview of resonance energy transfer (FRET) in dendritic molecules was performed. We focused mainly on constructs bearing peripheral pyrene groups as donor moieties using different acceptor groups, such as porphyrin, fullerene C60, ruthenium-bipyridine complexes, and cyclen-core. We have studied the effect of all the different donor-acceptor pairs in the energy transfer efficiency (FRET). In all cases, high FRET efficiency values were observed.

scholarly journals Design of Novel Pyrene-Bodipy Dyads: Synthesis, Characterization, Optical Properties, and FRET Studies

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2289 ◽  
Author(s):  
Pasquale Porcu ◽  
Mireille Vonlanthen ◽  
Israel González-Méndez ◽  
Andrea Ruiu ◽  
Ernesto Rivera
Keyword(s):  
First Generation ◽  
Photophysical Properties ◽  
Visible Region ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Spectroscopic Studies ◽  
Quantum Yields ◽  
Acceptor Pair ◽  
Donor Acceptor ◽  
Zero Generation

A new series of dendronized bodipys containing pyrene units was synthesized and characterized. Their optical and photophysical properties were determined by absorption and fluorescence spectroscopy. This series includes three different compounds. The first one has an anisole group linked to the bodipy unit, which was used as the reference compound. In the second, the bodipy core is linked to a zero generation dendron with one pyrene unit. The third compound contains a first generation Fréchet-type dendron bearing two pyrene units. In this work, the combination pyrene-bodipy was selected as the donor-acceptor pair for this fluorescence resonance energy transfer (FRET) study. Doubtless, these two chromophores exhibit high quantum yields, high extinction coefficients, and both their excitation and emission wavelengths are located in the visible region. This report presents a FRET study of a novel series of pyrene-bodipy dendritic molecules bearing flexible spacers. We demonstrated via spectroscopic studies that FRET phenomena occur in these dyads.

Quantum Dot Bioconjugates as Energy Donors in Fluorescence Resonance Energy Transfer Assays

2003 ◽  
Vol 773 ◽  
Author(s):  
Aaron R. Clapp ◽  
Igor L. Medintz ◽  
J. Matthew Mauro ◽  
Hedi Mattoussi
Keyword(s):  
Energy Transfer ◽  
Quantum Dot ◽  
Organic Dyes ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Genetically Engineered ◽  
Molar Ratio ◽  
Binding Assays ◽  
Specific Sequence ◽  
Donor Acceptor

AbstractLuminescent CdSe-ZnS core-shell quantum dot (QD) bioconjugates were used as energy donors in fluorescent resonance energy transfer (FRET) binding assays. The QDs were coated with saturating amounts of genetically engineered maltose binding protein (MBP) using a noncovalent immobilization process, and Cy3 organic dyes covalently attached at a specific sequence to MBP were used as energy acceptor molecules. Energy transfer efficiency was measured as a function of the MBP-Cy3/QD molar ratio for two different donor fluorescence emissions (different QD core sizes). Apparent donor-acceptor distances were determined from these FRET studies, and the measured distances are consistent with QD-protein conjugate dimensions previously determined from structural studies.

scholarly journals Photochemical Reactivity of Naphthol-Naphthalimide Conjugates and Their Biological Activity

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3355
Author(s):  
Matija Sambol ◽  
Patricia Benčić ◽  
Antonija Erben ◽  
Marija Matković ◽  
Branka Mihaljević ◽  
...  
Keyword(s):  
Biological Activity ◽  
Rational Design ◽  
Human Cancer ◽  
Photophysical Properties ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Quinone Methide ◽  
Quantum Yields ◽  
Photochemical Reactivity ◽  
Human Cancer Cell Lines

Quinone methide precursors 1a–e, with different alkyl linkers between the naphthol and the naphthalimide chromophore, were synthesized. Their photophysical properties and photochemical reactivity were investigated and connected with biological activity. Upon excitation of the naphthol, Förster resonance energy transfer (FRET) to the naphthalimide takes place and the quantum yields of fluorescence are low (ΦF ≈ 10−2). Due to FRET, photodehydration of naphthols to QMs takes place inefficiently (ΦR ≈ 10−5). However, the formation of QMs can also be initiated upon excitation of naphthalimide, the lower energy chromophore, in a process that involves photoinduced electron transfer (PET) from the naphthol to the naphthalimide. Fluorescence titrations revealed that 1a and 1e form complexes with ct-DNA with moderate association constants Ka ≈ 105–106 M−1, as well as with bovine serum albumin (BSA) Ka ≈ 105 M−1 (1:1 complex). The irradiation of the complex 1e@BSA resulted in the alkylation of the protein, probably via QM. The antiproliferative activity of 1a–e against two human cancer cell lines (H460 and MCF 7) was investigated with the cells kept in the dark or irradiated at 350 nm, whereupon cytotoxicity increased, particularly for 1e (>100 times). Although the enhancement of this activity upon UV irradiation has no imminent therapeutic application, the results presented have importance in the rational design of new generations of anticancer phototherapeutics that absorb visible light.

Controlling fluorescence resonance energy transfer of donor–acceptor dyes by Diels–Alder dynamic covalent bonds

2021 ◽  
Vol 57 (26) ◽  
pp. 3275-3278
Author(s):  
Yanhui Cui ◽  
Fen Li ◽  
Xin Zhang
Keyword(s):  
Energy Transfer ◽  
Fluorescence Resonance Energy Transfer ◽  
Aromatic Amine ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Diels Alder ◽  
Covalent Bonds ◽  
Donor Acceptor ◽  
Fluorescence Resonance ◽  
Mutual Conversion

Two new dyes, consisting of an aromatic amine donor and dansyl acceptor connected by Diels–Alder bonds, display a switchable energy transfer. Dynamic covalent properties enable the mutual conversion of the two dyes by maleimide exchanges.

scholarly journals Ureasil organic–inorganic hybrids as photoactive waveguides for conjugated polyelectrolyte luminescent solar concentrators

2017 ◽  
Vol 1 (11) ◽  
pp. 2271-2282 ◽  
Author(s):  
Ilaria Meazzini ◽  
Camille Blayo ◽  
Jochen Arlt ◽  
Ana-Teresa Marques ◽  
Ullrich Scherf ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Solar Concentrators ◽  
Conjugated Polyelectrolyte ◽  
Luminescent Solar Concentrators ◽  
Donor Acceptor

We test the potential of resonance energy transfer to enhance the performance of conjugated copolyelectrolyte donor–acceptor luminescent solar concentrators immobilised within a photoactive organic–inorganic ureasil waveguide.

Sign in / Sign up

Export Citation Format

Share Document