| 1. |
- Andersson, Johanna, 1983, et al.
(författare)
-
Photoswitched DNA-binding of a photochromic spiropyran
- 2008
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 130:36, s. 11836-11837
-
Tidskriftsartikel (refereegranskat)abstract
- The dramatically different DNA-binding properties of the two isomeric forms of a photochromic spiropyran have been demonstrated, enabling photoswitched DNA binding. The closed, UV-absorbing form shows no signs of interaction with DNA. Upon UV exposure the spiropyran is isomerized to the open form that binds to DNA by intercalation. The process is fully reversible as the corresponding dissociation process is induced by visible light. Copyright © 2008 American Chemical Society.
|
|
| 2. |
- Andreasson, Joakim, 1973, et al.
(författare)
-
All-photonic molecular half-adder
- 2006
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 128:50, s. 16259-16265
-
Tidskriftsartikel (refereegranskat)abstract
- One molecule acts as both an AND and an XOR Boolean logic gate that share the same two photonic inputs. The molecule comprises a half-adder, adding two binary digits with only light as inputs and outputs, and consists of three covalently linked photochromic moieties, a spiropyran and two quinolinederived dihydroindolizines. The AND function is based on the absorption properties of the molecule, whereas the XOR function is based on an off-on-off response of the fluorescence to the inputs that results from interchromophore excited-state quenching interactions. The half-adder is simple to operate and can be cycled many times.
|
|
| 3. |
- Andreasson, Joakim, 1973, et al.
(författare)
-
All-Photonic Multifunctional Molecular Logic Device
- 2011
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 133:30, s. 11641-11648
-
Tidskriftsartikel (refereegranskat)abstract
- Photochromes are photoswitchable, bistable chromophores which, like transistors, can implement binary logic operations. When several photochromes are combined in one molecule, interactions between them such as energy and electron transfer allow design of simple Boolean logic gates and more complex logic devices with all-photonic inputs and outputs. Selective isomerization of individual photochromes can be achieved using light of different wavelengths, and logic outputs can employ absorption and emission properties at different wavelengths, thus allowing a single molecular species to perform several different functions, even simultaneously. Here, we report a molecule consisting of three linked photochromes that can be configured as AND, XOR, INH, half-adder, half-subtractor, multiplexer, demultiplexer, encoder, decoder, keypad lock, and logically reversible transfer gate logic devices, all with a common initial state. The system demonstrates the advantages of light-responsive molecules as multifunctional, reconfigurable nanoscale logic devices that represent an approach to true molecular information processing units.
|
|
| 4. |
|
|
| 5. |
- Benitez-Martin, Carlos, 1994, et al.
(författare)
-
Toward Two-Photon Absorbing Dyes with Unusually Potentiated Nonlinear Fluorescence Response
- 2020
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 142:35, s. 14854-14858
-
Tidskriftsartikel (refereegranskat)abstract
- The combination of two two-photon-induced processes in a Förster resonance energy transfer (FRET)-operated photochromic fluorene-dithienylethene dyad lays the foundation for the observation of a quartic dependence of the fluorescence signal on the excitation light intensity. While this photophysical behavior is predicted for a four-photon absorbing dye, the herein proposed approach opens the way to use two-photon absorbing dyes, reaching the same performance. Hence, the spatial resolution limit, being a critical parameter for applications in fluorescence imaging or data storage with common two-photon absorbing dyes, is dramatically improved.
|
|
| 6. |
- Bälter, Magnus, 1986, et al.
(författare)
-
An All-Photonic Molecule-Based Parity Generator/Checker for Error Detection in Data Transmission
- 2013
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 135:28, s. 10230-10233
-
Tidskriftsartikel (refereegranskat)abstract
- The function of a parity generator/checker, which is an essential operation for detecting errors in data transmission, has been realized with multiphotochromic switches by taking advantage of a neuron-like fluorescence response and reversible light-induced transformations between the implicated isomers.
|
|
| 7. |
- Bälter, Magnus, 1986, et al.
(författare)
-
Reversible Energy-Transfer Switching on a DNA Scaffold
- 2015
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 137:7, s. 2444-2447
-
Tidskriftsartikel (refereegranskat)abstract
- We show that FRET between Pacific Blue (PB) and Alexa488 (A488) covalently attached to a DNAscaffold can be reversibly controlled by photochromicswitching of a spiropyran derivative. With the spiropyranin the closed spiro isomeric form, FRET occurs freelybetween PB and A488. UV-induced isomerization to theopen merocyanine form shuts down the FRET process byefficient quenching of the PB excited state. The process isreversed by exposure to visible light, triggering theisomerization to the spiro isomer.
|
|
| 8. |
- Canton, Martina, et al.
(författare)
-
Improving Fatigue Resistance of Dihydropyrene by Encapsulation within a Coordination Cage
- 2020
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 142:34, s. 14557-14565
-
Tidskriftsartikel (refereegranskat)abstract
- Photochromic molecules undergo reversible isomerization upon irradiation with light at different wavelengths, a process that can alter their physical and chemical properties. For instance, dihydropyrene (DHP) is a deep-colored compound that isomerizes to light-brown cyclophanediene (CPD) upon irradiation with visible light. CPD can then isomerize back to DHP upon irradiation with UV light or thermally in the dark. Conversion between DHP and CPD is thought to proceed via a biradical intermediate; bimolecular events involving this unstable intermediate thus result in rapid decomposition and poor cycling performance. Here, we show that the reversible isomerization of DHP can be stabilized upon confinement within a (PdIIL4)-L-6 coordination cage. By protecting this reactive intermediate using the cage, each isomerization reaction proceeds to higher yield, which significantly decreases the fatigue experienced by the system upon repeated photocycling. Although molecular confinement is known to help stabilize reactive species, this effect is not typically employed to protect reactive intermediates and thus improve reaction yields. We envisage that performing reactions under confinement will not only improve the cyclic performance of photochromic molecules, but may also increase the amount of product obtainable from traditionally low-yielding organic reactions.
|
|
| 9. |
- Chen, H. R., et al.
(författare)
-
Conformational effects of UV light on DNA origami
- 2017
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 139:4, s. 1380-1383
-
Tidskriftsartikel (refereegranskat)abstract
- The responses of DNA origami conformation to UV radiation of different wavelengths and doses are investigated. Short- and medium-wavelength UV light can cause photo-lesions in DNA origami. At moderate doses, the lesions do not cause any visible defects in the origami, nor do they significantly affect the hybridization capability. Instead, they help relieve the internal stress in the origami structure and restore it to the designed conformation. At high doses, staple dissociation increases which causes structural disintegration. Long-wavelength UV does not show any effect on origami conformation by itself. We show that this UV range can be used in conjunction with photoactive molecules for photo-reconfiguration, while avoiding any damage to the DNA structures.
|
|
| 10. |
- Fleming, Cassandra L., et al.
(författare)
-
Shining New Light on the Spiropyran Photoswitch: A Photocage Decides between cis-trans or Spiro-Merocyanine Isomerization
- 2018
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 140:43, s. 14069-14072
-
Tidskriftsartikel (refereegranskat)abstract
- Photochromic molecules from the spiropyran family are known to undergo light-induced interconversion between the colorless spiro- and the colored merocyanine forms. Here, we show for the first time that small structural modifications open up for an additional photoisomerization mode: reversible cis-trans isomerization of the merocyanine. Moreover, the introduction of a photocage allows for light-activated switching between the two modes.
|
|
