TY  - GEN
A1  - Wessig, Pablo
A1  - John, Leonard
A1  - Sperlich, Eric
A1  - Kelling, Alexandra
T1  - Sulfur tuning of [1,3]-dioxolo[4.5-f]benzodioxole (DBD) fluorescent dyes
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - The replacement of oxygen by sulfur atoms of [1,3]-dioxolo[4.5-f]benzodioxole (DBD) fluorescent dyes is an efficient way to adjust the photophysical properties (sulfur tuning). While previously developed S-4-DBD dyes exhibit considerably red-shifted absorption and emission wavelength, the heavy atom effect of four sulfur atoms cause low fluorescence quantum yields and short fluorescence lifetimes. Herein, we demonstrate that the replacement of less than four sulfur atoms (S-1-DBD, 1,2-S-2-DBD, and 1,4-S-2-DBD dyes) permits a fine-tuning of the photophysical properties. In some cases, a similar influence on the wavelength without the detrimental effect on the quantum yields and lifetimes is observed. Furthermore, the synthetic accessibility of S-1- and S-2-DBD dyes is improved, compared with S-4-DBD dyes. For coupling with biomolecules a series of reactive derivatives of the new dyes were developed (azides, OSu esters, alkynes, maleimides).
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1381 
KW  - fluorescent dyes
KW  - heterocycles
KW  - photophysics
KW  - stokes shift
KW  - sulfur
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-566241
SN  - 1866-8372
IS  - 3
ER  - 
TY  - JOUR
A1  - Strauss, Volker
A1  - Wang, Huize
A1  - Delacroix, Simon
A1  - Ledendecker, Marc
A1  - Wessig, Pablo
T1  - Carbon nanodots revised
BT  - the thermal citric acid/urea reaction
JF  - Chemical science
N2  - Luminescent compounds obtained from the thermal reaction of citric acid and urea have been studied and utilized in different applications in the past few years. The identified reaction products range from carbon nitrides over graphitic carbon to distinct molecular fluorophores. On the other hand, the solid, non-fluorescent reaction product produced at higher temperatures has been found to be a valuable precursor for the CO2-laser-assisted carbonization reaction in carbon laser-patterning. This work addresses the question of structural identification of both, the fluorescent and non-fluorescent reaction products obtained in the thermal reaction of citric acid and urea. The reaction products produced during autoclave-microwave reactions in the melt were thoroughly investigated as a function of the reaction temperature and the reaction products were subsequently separated by a series of solvent extractions and column chromatography. The evolution of a green molecular fluorophore, namely HPPT, was confirmed and a full characterization study on its structure and photophysical properties was conducted. The additional blue fluorescence is attributed to oligomeric ureas, which was confirmed by complementary optical and structural characterization. These two components form strong hydrogen-bond networks which eventually react to form solid, semi-crystalline particles with a size of similar to 7 nm and an elemental composition of 46% C, 22% N, and 29% O. The structural features and properties of all three main components were investigated in a comprehensive characterization study.
Y1  - 2020
U6  - https://doi.org/10.1039/d0sc01605e
SN  - 2041-6520
SN  - 2041-6539
VL  - 11
IS  - 31
SP  - 8256
EP  - 8266
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Wessig, Pablo
A1  - Badetko, Dominik
A1  - Czarnecki, Maciej
A1  - Wichterich, Lukas
A1  - Schmidt, Peter
A1  - Brudy, Cosima
A1  - Sperlich, Eric
A1  - Kelling, Alexandra
T1  - Studies toward the total synthesis of arylnaphthalene lignans via a Photo-Dehydro-Diels-Alder (PDDA) reaction
JF  - The journal of organic chemistry
N2  - An efficient method for the preparation of arylnaphthalene lignans (ANLs) was developed, which is based on thePhoto-Dehydro-DIELS-ALDER(PDDA) reaction. While intermolecular PDDA reactions turned out to be inefficient, theintramolecular variant using suberic acid as tether linking two aryl propiolic esters smoothly provided naphthalenophanes. Theirradiations were performed with a previously developed annular continuous-flow reactor and UVB lamps. In this way, the naturalproducts Alashinol D, Taiwanin C, and an unnamed ANL could be prepared.
Y1  - 2022
U6  - https://doi.org/10.1021/acs.joc.2c00195
SN  - 0022-3263
SN  - 1520-6904
VL  - 87
IS  - 9
SP  - 5904
EP  - 5915
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Haubitz, Toni
A1  - John, Leonard
A1  - Freyse, Daniel
A1  - Wessig, Pablo
A1  - Kumke, Michael Uwe
T1  - Investigating the Sulfur "Twist" on the Photophysics of DBD Dyes
JF  - The journal of physical chemistry : A, Molecules, spectroscopy, kinetics, environment & general theory
N2  - The so-called DBD ([1,3]dioxolo[4,5-f][1,3]benzodioxole) dyes are a new class of fluorescent dyes, with tunable photophysical properties like absorption, fluorescence lifetime, and Stokes shift. With the development of sulfur based DBDs, this dye class is extended even further for possible applications in spectroscopy and microscopy. In this paper we are investigating the basic photophysical properties and their implications for future applications for S-4-DBD as well as O-4-DBD. On the basis of time-resolved laser fluorescence spectroscopy, transient absorption spectroscopy, and UV/vis-spectroscopy, we determined the rate constants of the radiative and nonradiative deactivation processes as well as the energy of respective electronic states involved in the electronic deactivation of S-4-DBD and of O-4-DBD. For S-4-DBD we unraveled the triplet formation with intersystem crossing quantum yields of up to 80%. By TD-DFT calculations we estimated a triplet energy of around 13500-14700 cm(-1) depending on the DBD dye and solvent. Through solvent dependent measurements, we found quadrupole moments in the range of 2 B.
Y1  - 2020
U6  - https://doi.org/10.1021/acs.jpca.0c01880
SN  - 1089-5639
SN  - 1520-5215
VL  - 124
IS  - 22
SP  - 4345
EP  - 4353
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Wessig, Pablo
A1  - Freyse, Daniel
A1  - Schuster, David
A1  - Kelling, Alexandra
T1  - Fluorescent dyes with large stokes shifts based on Benzo[1,2-d:4,5-d']bis([1,3]dithiole) (“S4-DBD Dyes”)
JF  - Europan journal of organic chemistry
N2  - We report on a further development of [1,3]-dioxolo[4.5-f]benzodioxole (DBD) fluorescent dyes by replacement of the four oxygen atoms of the heterocyclic core by sulfur atoms. This variation causes striking changes of the photophysical properties. Whereas absorption and emission significantly shifted to longer wavelength, the fluorescence lifetimes and quantum yields are diminished compared to DBD dyes. The latter effect is presumably caused by an enhanced intersystem crossing to the triplet state due to the sulfur atoms. The very large Stokes shifts of the S-4-DBD dyes ranging from 3000 cm(-1) to 7400 cm(-1) (67 nm to 191 nm) should be especially emphasized. By analogy with DBD dyes a broad variation of absorption and emission wavelength is possible by introducing different electron withdrawing substituents. Moreover, some derivatives for coupling with biomolecules were developed.
KW  - fluorescent dyes
KW  - sulfur
KW  - heterocycles
KW  - stokes shift
KW  - photophysics
Y1  - 2020
U6  - https://doi.org/10.1002/ejoc.202000093
SN  - 1434-193X
SN  - 1099-0690
VL  - 2020
IS  - 11
SP  - 1732
EP  - 1744
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Wessig, Pablo
A1  - John, Leonard
A1  - Sperlich, Eric
A1  - Kelling, Alexandra
T1  - Sulfur tuning of [1,3]-dioxolo[4.5-f]benzodioxole (DBD) fluorescent dyes
JF  - European journal of organic chemistry
N2  - The replacement of oxygen by sulfur atoms of [1,3]-dioxolo[4.5-f]benzodioxole (DBD) fluorescent dyes is an efficient way to adjust the photophysical properties (sulfur tuning). While previously developed S-4-DBD dyes exhibit considerably red-shifted absorption and emission wavelength, the heavy atom effect of four sulfur atoms cause low fluorescence quantum yields and short fluorescence lifetimes. Herein, we demonstrate that the replacement of less than four sulfur atoms (S-1-DBD, 1,2-S-2-DBD, and 1,4-S-2-DBD dyes) permits a fine-tuning of the photophysical properties. In some cases, a similar influence on the wavelength without the detrimental effect on the quantum yields and lifetimes is observed. Furthermore, the synthetic accessibility of S-1- and S-2-DBD dyes is improved, compared with S-4-DBD dyes. For coupling with biomolecules a series of reactive derivatives of the new dyes were developed (azides, OSu esters, alkynes, maleimides).
KW  - fluorescent dyes
KW  - heterocycles
KW  - photophysics
KW  - stokes shift
KW  - sulfur
Y1  - 2020
U6  - https://doi.org/10.1002/ejoc.202001418
SN  - 1434-193X
SN  - 1099-0690
VL  - 2021
IS  - 3
SP  - 499
EP  - 511
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Wessig, Pablo
A1  - Krebs, Saskia
T1  - N-aroylsulfonamide-photofragmentation (ASAP)
BT  - a versatile route to biaryls
JF  - European journal of organic chemistry
N2  - The photochemical fragmentation of N-aroylsulfonamides 9 (ASAP) is a powerful method for the preparation of various biaryls. Compounds 9 are easily accessible in two steps from amines by treatment with arenesulfonyl chlorides and aroyl chlorides. Many of these compounds were prepared for the first time. The irradiation takes place in a previously developed continuous-flow reactor using inexpensive UVB or UVC fluorescent lamps. Isocyanates and sulphur dioxide are formed as the only by-products. The ASAP tolerates a variety of functional groups and is even suited for the preparation of phenylnaphthalenes and terphenyls. The ASAP mechanism was elucidated by interaction of photophysical and quantum chemical (DFT) methods and revealed a spirocyclic biradical as key intermediate.
KW  - Biaryls
KW  - Fragmentation
KW  - Isocyanates
KW  - Photochemistry
KW  - Sulfonamides
Y1  - 2021
U6  - https://doi.org/10.1002/ejoc.202100955
SN  - 1434-193X
SN  - 1099-0690
VL  - 2021
IS  - 46
SP  - 6367
EP  - 6374
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Meyners, Christian
A1  - Mertens, Monique
A1  - Wessig, Pablo
A1  - Meyer-Almes, Franz-Josef
T1  - A Fluorescence-Lifetime-Based Binding Assay for Class IIa Histone Deacetylases
JF  - Chemistry - a European journal
N2  - Class IIa histone deacetylases (HDACs) show extremely low enzymatic activity and no commonly accepted endogenous substrate is known today. Increasing evidence suggests that these enzymes exert their effect rather through molecular recognition of acetylated proteins and recruiting other proteins like HDAC3 to the desired target location. Accordingly, class IIa HDACs like bromodomains have been suggested to act as “Readers” of acetyl marks, whereas enzymatically active HDACs of class I or IIb are called “Erasers” to highlight their capability to remove acetyl groups from acetylated histones or other proteins. Small-molecule ligands of class IIa histone deacetylases (HDACs) have gained tremendous attention during the last decade and have been suggested as pharmaceutical targets in several indication areas such as cancer, Huntington's disease and muscular atrophy. Up to now, only enzyme activity assays with artificial chemically activated trifluoroacetylated substrates are in use for the identification and characterization of new active compounds against class IIa HDACs. Here, we describe the first binding assay for this class of HDAC enzymes that involves a simple mix-and-measure procedure and an extraordinarily robust fluorescence lifetime readout based on [1,3]dioxolo[4,5-f]benzodioxole-based ligand probes. The principle of the assay is generic and can also be transferred to class I HDAC8.
KW  - drug discovery
KW  - enzymes
KW  - fluorescent probes
KW  - high-throughput screening
KW  - hydrolases
Y1  - 2017
U6  - https://doi.org/10.1002/chem.201605140
SN  - 0947-6539
SN  - 1521-3765
VL  - 23
IS  - 13
SP  - 3107
EP  - 3116
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Wessig, Pablo
A1  - John, Leonard
A1  - Mertens, Monique
T1  - Extending the Class of [1,3]-Dioxolo[4.5-f]benzodioxole (DBD) Fluorescent Dyes
JF  - European journal of organic chemistry
N2  - Synthetic routes to a collection of new fluorescent dyes are described, which are based on the [1,3]-dioxolo[4.5-f]benzodioxole (DBD) core. By introducing different electron withdrawing groups in 4- and 8-position of the DBD moiety the emission wavelength could be adjusted over a large spectral range from blue to orange light.
KW  - Functional organic materials
KW  - Fluorescence
KW  - DBD dyes
KW  - Large Stokes shifts
KW  - Aryllithium compounds
KW  - Heterocycles
Y1  - 2018
U6  - https://doi.org/10.1002/ejoc.201800002
SN  - 1434-193X
SN  - 1099-0690
VL  - 2018
IS  - 14
SP  - 1674
EP  - 1681
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Mertens, Monique
A1  - Hilsch, Malte
A1  - Haralampiev, Ivan
A1  - Volkmer, Rudolf
A1  - Wessig, Pablo
A1  - Müller, Peter
T1  - Synthesis and characterization of a new Bifunctionalized, Fluorescent, and Amphiphilic molecule for recruiting SH-Containing molecules to membranes
JF  - ChemBioChem
N2  - This study describes the synthesis and characterization of an amphiphilic construct intended to recruit SH-containing molecules to membranes. The construct consists of 1)an aliphatic chain to enable anchoring within membranes, 2)a maleimide moiety to react with the sulfhydryl group of a soluble (bio)molecule, and 3)a fluorescence moiety to allow the construct to be followed by fluorescence spectroscopy and microscopy. It is shown that the construct can be incorporated into preformed membranes, thus allowing application of the approach with biological membranes. The close proximity between the fluorophore and the maleimide moiety within the construct causes fluorescence quenching. This allows monitoring of the reaction with SH-containing molecules by measurement of increases in fluorescence intensity and lifetime. Notably, the construct distributes into laterally ordered membrane domains of lipid vesicles, which is probably triggered by the length of its membrane anchor. The advantages of the new construct can be employed for several biological, biotechnological, and medicinal applications.
KW  - DBD dyes
KW  - fatty acids
KW  - liposomes
KW  - maleimide
KW  - membranes
KW  - palmitoylation
Y1  - 2018
U6  - https://doi.org/10.1002/cbic.201800268
SN  - 1439-4227
SN  - 1439-7633
VL  - 19
IS  - 15
SP  - 1643
EP  - 1647
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Büchner, Dörthe
A1  - John, Leonard
A1  - Mertens, Monique
A1  - Wessig, Pablo
T1  - Detection of dsDNA with [1,3]Dioxolo[4,5-f]benzodioxol (DBD) Dyes
JF  - Chemistry - a European journal
N2  - DBD fluorescent dyes have proven to be useful in numerous applications. To widen the range of biological applications, we propose three different types of DBD molecules that have been modified in such a way that DNA interaction becomes probable. After the successful synthesis of all three compounds, we tested their fluorescent properties and their DNA binding abilities. Two of the three probes exhibit an interaction with dsDNA with subsequent fluorescence enhancement. The determined binding constants of the two new DNA dyes are comparable to other minorgroove-binding dyes. Their large Stokes shifts and their long fluorescent lifetimes are outstanding features of these dyes.
KW  - DNA recognition
KW  - dyes/pigments
KW  - fluorescent probes
KW  - heterocycles
KW  - scatchard plot
Y1  - 2018
U6  - https://doi.org/10.1002/chem.201804057
SN  - 0947-6539
SN  - 1521-3765
VL  - 24
IS  - 60
SP  - 16183
EP  - 16190
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - López de Guereñu, Anna
A1  - Bastian, Philipp
A1  - Wessig, Pablo
A1  - John, Leonard
A1  - Kumke, Michael Uwe
T1  - Energy Transfer between Tm-Doped Upconverting Nanoparticles and a Small Organic Dye with Large Stokes Shift
JF  - Biosensors : open access journal
N2  - Lanthanide-doped upconverting nanoparticles (UCNP) are being extensively studied for bioapplications due to their unique photoluminescence properties and low toxicity. Interest in RET applications involving UCNP is also increasing, but due to factors such as large sizes, ion emission distributions within the particles, and complicated energy transfer processes within the UCNP, there are still many questions to be answered. In this study, four types of core and core-shell NaYF4-based UCNP co-doped with Yb3+ and Tm3+ as sensitizer and activator, respectively, were investigated as donors for the Methyl 5-(8-decanoylbenzo[1,2-d:4,5-d ']bis([1,3]dioxole)-4-yl)-5-oxopentanoate (DBD-6) dye. The possibility of resonance energy transfer (RET) between UCNP and the DBD-6 attached to their surface was demonstrated based on the comparison of luminescence intensities, band ratios, and decay kinetics. The architecture of UCNP influenced both the luminescence properties and the energy transfer to the dye: UCNP with an inert shell were the brightest, but their RET efficiency was the lowest (17%). Nanoparticles with Tm3+ only in the shell have revealed the highest RET efficiencies (up to 51%) despite the compromised luminescence due to surface quenching.
KW  - resonance energy transfer
KW  - DBD dye
KW  - core shell UCNP
KW  - time-resolved luminescence
Y1  - 2019
U6  - https://doi.org/10.3390/bios9010009
SN  - 2079-6374
VL  - 9
IS  - 1
PB  - MDPI
CY  - Basel
ER  - 
TY  - GEN
A1  - Schwarze, Thomas
A1  - Riemer, Janine
A1  - Müller, Holger
A1  - John, Leonard
A1  - Holdt, Hans‐Jürgen
A1  - Wessig, Pablo
T1  - Na+ Selective Fluorescent Tools Based on Fluorescence Intensity Enhancements, Lifetime Changes, and on a Ratiometric Response
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Over the years, we developed highly selective fluorescent probes for K+ in water, which show K+-induced fluorescence intensity enhancements, lifetime changes, or a ratiometric behavior at two emission wavelengths (cf. Scheme 1, K1-K4). In this paper, we introduce selective fluorescent probes for Na+ in water, which also show Na+ induced signal changes, which are analyzed by diverse fluorescence techniques. Initially, we synthesized the fluorescent probes 2, 4, 5, 6 and 10 for a fluorescence analysis by intensity enhancements at one wavelength by varying the Na+ responsive ionophore unit and the fluorophore moiety to adjust different K-d values for an intra- or extracellular Na+ analysis. Thus, we found that 2, 4 and 5 are Na+ selective fluorescent tools, which are able to measure physiologically important Na+ levels at wavelengths higher than 500 nm. Secondly, we developed the fluorescent probes 7 and 8 to analyze precise Na+ levels by fluorescence lifetime changes. Herein, only 8 (K-d=106 mm) is a capable fluorescent tool to measure Na+ levels in blood samples by lifetime changes. Finally, the fluorescent probe 9 was designed to show a Na+ induced ratiometric fluorescence behavior at two emission wavelengths. As desired, 9 (K-d=78 mm) showed a ratiometric fluorescence response towards Na+ ions and is a suitable tool to measure physiologically relevant Na+ levels by the intensity change of two emission wavelengths at 404 nm and 492 nm.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1136 
KW  - crown compounds
KW  - fluorescence lifetime
KW  - fluorescent probes
KW  - ratiometric
KW  - sodium
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-437482
SN  - 1866-8372
IS  - 1136
ER  - 
TY  - JOUR
A1  - Riemer, Nastja
A1  - Shipman, Michael
A1  - Wessig, Pablo
A1  - Schmidt, Bernd
T1  - Iterative arylation of itaconimides with diazonium salts through electrophilic palladium catalysis
BT  - divergent beta-H-Elimination pathways in repetitive Matsuda-Heck reactions
JF  - The journal of organic chemistry
N2  - N-Arylitaconimides, accessible from maleic anhydride, anilines, and paraformaldehyde, react with arene diazonium salts in Pd-catalyzed Matsuda-Heck arylation to the pharmacologically relevant E-configured 3-arylmethylidene pyrrolidine-2,5-diones (also known as arylmethylidene succinimides) through exo-selective beta-H-elimination. The coupling proceeds at ambient temperature with the simple and easy-to-handle precatalyst Pd-II-acetate under ligandand base-free conditions. Notable features are high isolated yields, regio- and stereoselectivities, and short reaction times. In a comparative investigation, aryl iodides, bromides, and triflates were shown to be inferior coupling reagents in this reaction. The 3-arylmethylidene pyrrolidine-2,5-diones undergo second Matsuda-Heck coupling, which proceeds via endo-selective beta-H-elimination to give diarylmethyl-substituted maleimides as coupling products. These products can also be accessed in one flask by sequential addition of different arene diazonium salts to the starting itaconimide. The potential of 3-arylmethylidene succinimides as photoswitches was tested. Upon irradiation of the E-isomer at 300 nm, partial isomerization to the Z-isomer (E/Z = 65:35 in the photostationary state) was observed. The isomerization was found to be nearly completely reversible by irradiating the mixture at 400 nm.
Y1  - 2019
U6  - https://doi.org/10.1021/acs.joc.9b00627
SN  - 0022-3263
VL  - 84
IS  - 9
SP  - 5732
EP  - 5746
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Haubitz, Toni
A1  - John, Leonard
A1  - Wessig, Pablo
A1  - Kumke, Michael Uwe
T1  - Photophysics of Acyl- and Ester-DBD Dyes
BT  - Quadrupole-Induced Solvent Relaxation Investigated by Transient Absorption Spectroscopy
JF  - the journal of physical chemistry : A, Molecules, spectroscopy, kinetics, environment & general theory
N2  - A new generation of wavelength-tunable, fluorescent dyes, so-called DBD ([1,3]dioxolo[4,5-f][1,3]benzodioxole) dyes, were developed a few years ago, and they showed great potential as probes, for example, for fluorescence microscopy. However, their photophysics is not fully explored and leaves open questions regarding their large fluorescence Stokes shifts and sensitivity to solvent conditions of differently substituted DBD dyes. To improve the understanding of the influence of the substitution pattern of the DBD dyes on their respective photophysics, transient absorption spectroscopy (TAS) was used, that is, a pump-probe experiment on the femtosecond timescale. TAS allows measurements of excited states, ground state recovery, solvent relaxation, and fluorescence properties on time scales of up to several nanoseconds. Two different DBD dye samples were investigated: aryl- and ester-substituted DBD dyes. Experiments were carried out in solvents with different polarities using different excitation energies and at different viscosities. Based on the experimental data and theoretical calculations, we were able to determine the conformational changes of the molecule due to electronic excitation and were able to investigate solvent relaxation processes for both types of DBD dyes. By generalizing the theory for quadrupole-induced solvent relaxation developed by Togashi et al., we derived quadrupole moments of both molecules in the ground and excited state. Our data showed differences in the binding of polar solvent molecules to the dyes depending on the substituent on the DBD dye. In the case of water as the solvent, an additional efficient quenching process in the electronically excited state was revealed, which was indicated by the observation of solvated electrons in the TAS signals.
Y1  - 2019
U6  - https://doi.org/10.1021/acs.jpca.9b02973
SN  - 1089-5639
VL  - 123
IS  - 22
SP  - 4717
EP  - 4726
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Czarnecki, Maciej
A1  - Wessig, Pablo
T1  - Scaling Up UV-Mediated Intramolecular Photodehydro-Diels-Alder Reactions Using a Homemade High-Performance Annular Continuous-Flow Reactor
JF  - Organic Process Research & Development
N2  - Here we present a self-made annular continuous-flow reactor that can be used in the UV/vis range in an internal numbering-up manner. As a model reaction, we chose a powerful batch-scale-limited benzoannelation method, namely, an intramolecular photodehydro-Diels-Alder (IMPDDA) reaction. The scale-up potential of this particular photochemical benchmark reaction toward the preparation of macrocylic (1,7)naphthalenophanes by variation of selected flow parameters is presented.
KW  - flow photochemistry
KW  - photocycloaddition
KW  - photodehydro-Diels-Alder reaction
KW  - scale-up
Y1  - 2018
U6  - https://doi.org/10.1021/acs.oprd.8b00353
SN  - 1083-6160
SN  - 1520-586X
VL  - 22
IS  - 12
SP  - 1823
EP  - 1827
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Hoang, Hoa T.
A1  - Mertens, Monique
A1  - Wessig, Pablo
A1  - Sellrie, Frank
A1  - Schenk, Jörg A.
A1  - Kumke, Michael Uwe
T1  - Antibody Binding at the Liposome-Water Interface
BT  - a FRET Investigation toward a Liposome-Based Assay
JF  - ACS Omega
N2  - Different signal amplification strategies to improve the detection sensitivity of immunoassays have been applied which utilize enzymatic reactions, nanomaterials, or liposomes. The latter are very attractive materials for signal amplification because liposomes can be loaded with a large amount of signaling molecules, leading to a high sensitivity. In addition, liposomes can be used as a cell-like "bioscaffold" to directly test recognition schemes aiming at cell-related processes. This study demonstrates an easy and fast approach to link the novel hydrophobic optical probe based on [1,3]dioxolo[4,5-f]-[1,3]benzodioxole (DBD dye mm239) with tunable optical properties to hydrophilic recognition elements (e.g., antibodies) using liposomes for signal amplification and as carrier of the hydrophobic dye. The fluorescence properties of mm239 (e.g., long fluorescence lifetime, large Stokes shift, high photostability, and high quantum yield), its high hydrophobicity for efficient anchoring in liposomes, and a maleimide bioreactive group were applied in a unique combination to build a concept for the coupling of antibodies or other protein markers to liposomes (coupling to membranes can be envisaged). The concept further allowed us to avoid multiple dye labeling of the antibody. Here, anti-TAMRA-antibody (DC7-Ab) was attached to the liposomes. In proof-of-concept, steady-state as well as time-resolved fluorescence measurements (e.g., fluorescence depolarization) in combination with single molecule detection (fluorescence correlation spectroscopy, FCS) were used to analyze the binding interaction between DC7-Ab and liposomes as well as the binding of the antigen rhodamine 6G (R6G) to the antibody. Here, the Forster resonance energy transfer (FRET) between mm239 and R6G was monitored. In addition to ensemble FRET data, single-molecule FRET (PIE-FRET) experiments using pulsed interleaved excitation were used to characterize in detail the binding on a single-molecule level to avoid averaging out effects.
KW  - energy-transfer
KW  - immunoassay
KW  - complexes
KW  - probes
Y1  - 2018
U6  - https://doi.org/10.1021/acsomega.8b03016
SN  - 2470-1343
VL  - 3
IS  - 12
SP  - 18109
EP  - 18116
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - GEN
A1  - Wessig, Pablo
A1  - Matthes, Annika
T1  - Photochemical synthesis and properties of 1,6- and 1,8-Naphthalenophanes
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Various 1,6- and 1,8-naphthalenophanes were synthesized by using the Photo-Dehydro-Diels-Alder (PDDA) reaction of bis-ynones. These compounds are easily accessible from omega-(3-iodophenyl)carboxylic acids in three steps. The obtained naphthalenophanes are axially chiral and the activation barrier for the atropisomerization could be determined in some cases by means of dynamic NMR (DNMR) and/or dynamic HPLC (DHPLC) experiments.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1042 
KW  - photo-dehydro-Diels-Alder reaction
KW  - naphthalenophanes
KW  - atropisomerism
KW  - dynamic NMR
KW  - dynamic HPLC
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-476675
SN  - 1866-8372
IS  - 1042
ER  - 
TY  - JOUR
A1  - Schwarze, Thomas
A1  - Riemer, Janine
A1  - Müller, Holger
A1  - John, Leonard
A1  - Holdt, Hans-Jürgen
A1  - Wessig, Pablo
T1  - Na+ Selective Fluorescent Tools Based on Fluorescence Intensity Enhancements, Lifetime Changes, and on a Ratiometric Response
JF  - Chemistry - a European journal
N2  - Over the years, we developed highly selective fluorescent probes for K+ in water, which show K+-induced fluorescence intensity enhancements, lifetime changes, or a ratiometric behavior at two emission wavelengths (cf. Scheme 1, K1-K4). In this paper, we introduce selective fluorescent probes for Na+ in water, which also show Na+ induced signal changes, which are analyzed by diverse fluorescence techniques. Initially, we synthesized the fluorescent probes 2, 4, 5, 6 and 10 for a fluorescence analysis by intensity enhancements at one wavelength by varying the Na+ responsive ionophore unit and the fluorophore moiety to adjust different K-d values for an intra- or extracellular Na+ analysis. Thus, we found that 2, 4 and 5 are Na+ selective fluorescent tools, which are able to measure physiologically important Na+ levels at wavelengths higher than 500 nm. Secondly, we developed the fluorescent probes 7 and 8 to analyze precise Na+ levels by fluorescence lifetime changes. Herein, only 8 (K-d=106 mm) is a capable fluorescent tool to measure Na+ levels in blood samples by lifetime changes. Finally, the fluorescent probe 9 was designed to show a Na+ induced ratiometric fluorescence behavior at two emission wavelengths. As desired, 9 (K-d=78 mm) showed a ratiometric fluorescence response towards Na+ ions and is a suitable tool to measure physiologically relevant Na+ levels by the intensity change of two emission wavelengths at 404 nm and 492 nm.
KW  - crown compounds
KW  - fluorescence lifetime
KW  - fluorescent probes
KW  - ratiometric
KW  - sodium
Y1  - 2019
U6  - https://doi.org/10.1002/chem.201902536
SN  - 0947-6539
SN  - 1521-3765
VL  - 25
IS  - 53
SP  - 12412
EP  - 12422
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - GEN
A1  - López de Guereñu, Anna
A1  - Bastian, Philipp
A1  - Wessig, Pablo
A1  - John, Leonard
A1  - Kumke, Michael Uwe
T1  - Energy transfer between tm-doped upconverting nanoparticles and a small organic dye with large stokes shift
T2  - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2  - Lanthanide-doped upconverting nanoparticles (UCNP) are being extensively studied for bioapplications due to their unique photoluminescence properties and low toxicity. Interest in RET applications involving UCNP is also increasing, but due to factors such as large sizes, ion emission distributions within the particles, and complicated energy transfer processes within the UCNP, there are still many questions to be answered. In this study, four types of core and core-shell NaYF4-based UCNP co-doped with Yb3+ and Tm3+ as sensitizer and activator, respectively, were investigated as donors for the Methyl 5-(8-decanoylbenzo[1,2-d:4,5-d ']bis([1,3]dioxole)-4-yl)-5-oxopentanoate (DBD-6) dye. The possibility of resonance energy transfer (RET) between UCNP and the DBD-6 attached to their surface was demonstrated based on the comparison of luminescence intensities, band ratios, and decay kinetics. The architecture of UCNP influenced both the luminescence properties and the energy transfer to the dye: UCNP with an inert shell were the brightest, but their RET efficiency was the lowest (17%). Nanoparticles with Tm3+ only in the shell have revealed the highest RET efficiencies (up to 51%) despite the compromised luminescence due to surface quenching.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 961 
KW  - resonance energy transfer
KW  - DBD dye
KW  - core shell UCNP
KW  - time-resolved luminescence
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-472240
SN  - 1866-8372
IS  - 961
ER  -