Joakim Andreasson

Chalmers University of Technology · Department of Chemical and Biological Engineering

Optoelectronic properties of atomically-thin MoS 2 flakes are modulated using photochromic diarylethene molecules. The layer-number-dependent charge transfer behaviors at the hybrid heterointerface are elucidated.

All-visible light-activated diarylethene (DAE) photoswitches are highly attractive for applications in smart photoresponsive materials. The photocyclization of DAE via the low-lying excited triplet state through triplet energy transfer (TET) from a sensitizer has been proven to be an effective approach for the realization of this scheme. However, t...

Two-dimensional (2D) transition metal dichalcogenide semiconductors have garnered significant attention due to their extraordinary electrical and optical properties. It has been increasingly important to develop strategies for modulating their properties. A number of methods have been introduced, including doping, electric and magnetic fields, mech...

Light-responsive molecular tools targeting kinases affords one the opportunity to study the underlying cellular function of selected kinases. In efforts to externally control lymphocyte-specific protein tyrosine kinase (LCK) activity, the development of release-and-report LCK inhibitors is described, in which (i) the release of the active kinase in...

The ability to modulate optical and electrical properties of two-dimensional (2D) semiconductors has sparked considerable interest in transition metal dichalcogenides (TMDs). Herein, we introduce a facile strategy for modulating optoelectronic properties of monolayer MoSe2 with external light. Photochromic diarylethene (DAE) molecules formed a 2-nm...

Merocyanines (MC) usually adopt ring opened zwitterionic structures that are interconvertible with their ring‐closed spiropyran photoisomers. By methylating the phenolate oxygen, and thereby blocking the ring‐closure reaction, a cis/trans‐only MC photoswitch was obtained, yielding a perfect candidate for a detailed examination of the cis/trans isom...

Herein, we report a tri‐component photochromic molecular cocktail that can be used to encrypt and decrypt information. The time‐dependent fluorescent response of this cocktail is highly non‐linear with respect to the set of inputs used (concentrations of the three photochromic components, excitation‐ and emission wavelengths), a property required f...

Solvatochromic dyes are prime candidates for exploring complex polarity-dependent biological processes. The design of novel dyes for these applications typically presents long synthetic routines. Herein we report a concise synthesis of azido-functionalised push-pull fluorenes, belonging to the most potent groups of fluorosolvatochromic compounds. T...

Molecular polaritons are hybrid light-matter states that emerge when a molecular transition strongly interacts with photons in a resonator. At optical frequencies, this interaction unlocks a way to explore and control new chemical phenomena at the nanoscale. Achieving such control at ultrafast timescales, however, is an outstanding challenge, as it...

Green‐to‐blue triplet–triplet annihilation photon upconversion with the well‐studied upconversion pair 9,10‐diphenylanthracene (DPA)/platinum octaethylporphyrin (PtOEP) was used to reversibly drive the photoisomerization of diarylethene (DAE) photoswitches by using visible light. By carefully selecting the kinetic and spectral properties of the mol...

Self-assembled peptide nanostructures with stimuli-responsive features are promising as functional materials. Despite extensive research efforts, water-soluble supramolecular constructs that can interact with lipid membranes in a controllable way are still challenging to achieve. Here, we have employed a short membrane anchor protein motif (GLFD) a...

Precisely modulated photoluminescence (PL) with external control is highly demanded in material and biological sciences. However, it is challenging to switch the PL on and off in the NIR region with a high modulation contrast. Here, we demonstrate that reversible on and off switching of the PL in the NIR region can be achieved in a bicomponent syst...

Logic operations are typically performed by silicon‐based microprocessors. Over the last 30 years, research groups are aiming at teaching molecules to do so too. This research field is referred to as molecular logic, or molecular information processing. While the inputs and outputs in the traditional devices are voltage driven, the molecular versio...

We study coupling of merocyanine to aluminum nanoantennas in weak and strong interaction regimes. Experiments reveal modification of the molecular dynamics induced by the plasmons as verified by quantum modelling of the hybrid system.

Molecular polaritons are hybrid light-matter states that emerge when a molecular transition strongly interacts with photons in a resonator. At optical frequencies, this interaction unlocks a way to explore and control new chemical phenomena at the nanoscale. Achieving such a control at ultrafast timescales, however, is an outstanding challenge, as...

The application of merocyanine photoacids has previously been largely limited to neutral and acidic pH values. Here we introduce a new merocyanine photoacid with superior pH switching qualities. By increasing...

REarranged during Transfection (RET) is a transmembrane receptor tyrosine kinase that is required for development of multiple human tissues, but which is also an important contributor to human cancers. RET activation through rearrangement or point mutations occurs in thyroid and lung cancers. Furthermore, activation of wild type RET is an increasin...

The application of merocyanine photoacids has been previously largely limited to neutral and acidic pH values. Here we introduce a new merocyanine photoacid with superior pH switching qualities. By increasing the pKa in the dark (pKadark) and the solubility we increased the reversible visible light induced pH jump to 3.5 units. Moreover, it is the...

Coupling semiconducting nanocrystals (NCs) with organic molecules provides an efficient route to generate and transfer triplet excitons. These excitons can be used to power photochemical transformations such as photoisomerization reactions...

Coupling semiconducting nanocrystals (NCs) with organic molecules provides an efficient route to generate and transfer triplet excitons. These excitons can be used to power photochemical transformations such as photoisomerization reactions using low energy radiation. Thus, it is desirable to develop a general approach that can efficiently be used t...

Molecular photoswitches capable of generating precise pH changes will allow pH-dependent processes to be controlled remotely and noninvasively with light. We introduce a series of new merocyanine photoswitches, which deliver reversible bulk pH changes up to 3.2 pH units (pH 6.5 to pH 3.3) upon irradiation with 450 nm light, displaying tunable and p...

We report the synthesis and characterisation of a photoswitchable DFG-out kinase inhibitor. Photocontrol of the target kinase in both enzymatic and living cell assays is demonstrated.

Molecular photoswitches capable of generating pH changes with precision will allow pH-dependent processes to be controlled remotely and non-invasively with light. We introduce a series of new spiropyran photoswitches, delivering reversible bulk pH changes up to 3.2 pH units (pH 6.5 to pH 3.3) upon irradiation with 450 nm light, displaying tunable a...

Molecular photoswitches capable of generating pH changes with precision will allow pH-dependent processes to be controlled remotely and non-invasively with light. We introduce a series of new spiropyran photoswitches, delivering reversible bulk pH changes up to 3.2 pH units (pH 6.5 to pH 3.3) upon irradiation with 450 nm light, displaying tunable a...

Molecular photoswitches capable of generating pH changes with precision will allow pH-dependent processes to be controlled remotely and non-invasively with light. We introduce a series of new spiropyran photoswitches, delivering reversible bulk pH changes up to 3.2 pH units (pH 6.5 to pH 3.3) upon irradiation with 450 nm light, displaying tunable a...

Molecular photoswitches capable of generating pH changes with precision will allow pH-dependent processes to be controlled remotely and non-invasively with light. We introduce a series of new spiropyran photoswitches, delivering reversible bulk pH changes up to 3.2 pH units (pH 6.5 to pH 3.3) upon irradiation with 450 nm light, displaying tunable a...

A water soluble diarylethene (DAE) derivative that displays exceptionally intense fluorescence from the colorless open form has been synthesized and characterized using UV/vis spectroscopy and fluorescence microscopy. We show that the bright emission from the open form can be rapidly switched using amplitude modulated red light, that is, by light a...

In this Review the use of light to address stimuli-responsive molecular and supramolecular systems with applications in information processing and binary logic is discussed. Molecular photoswitches are at the focal point of the herein summarized works. Light offers great advantages in terms of spatiotemporal control and remote triggering. As an add...

The combination of two two-photon-induced processes in a FRET-operated photochromic fluorene-dithienylethene dyad lays the fundament 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 op...

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 b...

A molecular cocktail containing two photochromic diarylethene derivatives that displays multicolor emission spanning blue-green to orange in a color-correlated fashion has been devised. The function does not rely on excited state communication such as energy transfer reactions, which is the typical case for similar systems. Instead, harnessing the...

The binding of donor‐acceptor Stenhouse adducts (DASAs) bearing hydrogen‐bond recognition groups by Hamilton‐type receptors significantly influenced their photoswitching properties by altering thermal barriers to isomerization. The thermal barrier between the most stable linear isomer and the photogenerated isomer is lowered on binding to a recepto...

A cocktail combination of stimuli responsive materials, a photoswitch and gelator, is used for multicolored emission tuning.

Three visible‐light responsive photoswitches are reported, azobis(1‐methyl‐benzimidazole) (1), azobis(benzoxazole) (2) and azobis(benzothiazole) (3). Photostationary distributions are obtained upon irradiation with visible light comprising approximately 80 % of the thermally unstable isomer, with thermal half‐lives up to 8 min and are mostly invari...

div> Controlling spectral and physicochemical properties with external stimuli is vital for the development of smart materials. Here we demonstrate a supramolecular gelator based on a fluorescent oxotriphenylhexanoate (OTHO) that can switch emission profiles between the solution and gel phase. Furthermore, a cocktail of the gelator and a photochro...

The development of a fluorescent LCK inhibitor that exhibits favourable solvatochromic properties upon binding the kinase is described. Fluorescent properties were realised through the inclusion of a prodan‐derived fluorophore into the pharmacophore of an ATP‐competitive kinase inhibitor. Fluorescence titration experiments demonstrate the solvatoch...

On-command changes in the emission color of functional materials is a sought-after property in many contexts. Of particular interest are systems using light as the external trigger to induce the color changes. Here we report on a tri-component cocktail consisting of a fluorescent donor molecule and two photochromic acceptor molecules encapsulated i...

The development of a fluorescent LCK inhibitor that exhibits favourable solvatochromic properties upon binding the kinase enzyme is described. Fluorescent properties were realised through the inclusion of a Prodan‐derived fluorophore into the pharmacophore of the ATP‐competitive kinase inhibitor. Fluorescence titration experiments exemplify the sol...

The composition of a supramolecular network, constituted by several cucurbituril receptors and guests, can be controlled by the reversible and all-photonic switching of a dithienylethene guest.

The reaction of 4,4′,4′′,4′′′‐(ethene‐1,1,2,2‐tetrayl)tetraaniline with 2‐pyridinecarboxaldehyde and iron(II) chloride resulted, after aqueous workup, in the diastereoselective formation of an [Fe2L3]⁴⁺ triple‐stranded helicate structure, irrespective of the stoichiometry employed. The helicate structure was characterized in solution by multinuclea...

The underlying role that many kinases play in complex cellular pathways as well as disease remains unclear. To better understand the role that kinases play in both health and disease states, the use of light as an external stimulus to modulate kinase activity with high spatiotemporal resolution has gained increasing interest over the years. Herein...

Photochromic [Pd2L4] coordination cages based on dithienylethene (DTE) ligands L allow triggering guest uptake and release by irradiation with light of different wavelengths. The process involves four consecutive electrocyclic reactions to convert all chromophores between their open and closed photoisomeric forms. So far, guest affinity of the full...

DNA binding modes of the stereoisomeric rotamers of two dithenylethene derivatives (DTE1 and DTE2) representing candidate photopharmacological switches have been identified and characterized in terms of their binding energies and electronic circular dichroism (CD) responses. In open form, two binding modes are identified namely minor-groove binding...

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 photo-isomerization mode: reversible cis-trans isomerization of the merocyanine. Moreover,...

The photo- and acidochromic properties of a new generation norbornadiene derivative have been harnessed for the realization of a three-input keypad lock, where a specific sequence of inputs induces a unique output. Reversible quadricyclane/norbornadiene photoisomerization is reported, and this rare feature allows the first example of a norbornadien...

A facile cocktail approach implying the mixing of diarylethene (DAE) photoswitches and low molecular weight gelators (LMWG) is presented. The photoresponsive gels exhibit multicolored emission that can be precisely controlled by different light exposure schemes (wavelength and dose), applicable for fluorescence patterning/writing. Including also a...

A set of azoheteroarenes have been synthesized with Buchwald–Hartwig coupling and microwave-assisted O2 oxidation as the key steps. Several compounds exhibit good to excellent photoswitching properties (high switching efficiency, good fatigue resistance, and thermal stability of Z-isomer) relevant for photocontrolled applications, which pave the wa...

The idea of using molecules in the context of information security has sparked the interest of researchers from many scientific disciplines. This is clearly manifested in the diversity of the molecular platforms and the analytical techniques used for this purpose, some of which we highlight in this Tutorial Review. Moreover, those molecular systems...

Herein, we report the first example of one-time password (OTP) generation and two-factor authentication (2FA) using a molecular approach. OTPs are passwords that are valid for one entry only. For the next login session, a new, different password is generated. This brings the advantage that any undesired recording of a password will not risk the sec...

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...

A series of photochromic diarylmaleimide derivatives has been synthesized and studied with respect to the photochromic properties in aqueous solution. The main rationale is to investigate if these compounds could be used as photoswitchable units in biological contexts, motivated by the fact that the diarylmaleimide structural motif is identified in...

We encapsulate a fluorescent donor molecule and a photochromic acceptor unit (photoswitch) in polymer micelles and show that the color of the emitted fluorescence is continuously changed from blue to yellow upon light-induced isomerization of the acceptor. Interestingly, white-light generation is achieved in between. With the photoswitch in the col...

DNA origami has received enormous attention for its ability to program complex nanostructures with a few nanometer precision. Dynamic origami structures that change conformation in response to environmental cues or external signals hold great promises in sensing and actuation at the nanoscale. The reconfiguration mechanism of existing dynamic origa...

The photo-controlled shift of pH titration curves, describing the acidochromic behaviour of a spiropyran switch network, was harnessed for the realisation of a molecular triode. The intricate network can be correctly interpreted with respect to the pH dependence of the main involved species.

Proto-oncogene tyrosine-protein kinase receptor RET is implicated in the development and maintenance of neurons of the central and peripheral nervous systems. Attaching activity-compromising photocleavable groups (caging) to inhibitors could allow for external spatiotemporally controlled inhibition using light, potentially providing novel informati...

REarranged during Transfection (RET) is a transmembrane receptor tyrosine kinase required for normal development and maintenance of neurons of the central and peripheral nervous systems. Deregulation of RET and hyperactivity of the RET kinase is intimately connected to several types of human cancers, most notably thyroid cancers, making it an attra...

Small molecule nonpeptidic mimics of α-helices are widely recognised as protein-protein interaction (PPIs) inhibitors. Protein-protein interactions mediate virtually all important regulatory pathways in a cell, and the ability to control and modulate PPIs is therefore of great significance to basic biology, where controlled disruption of protein ne...

We show that FRET between Pacific Blue (PB) and Alexa488 (A488) covalently attached to a DNA scaffold can be reversibly controlled by photochromic switching of a spiropyran derivative. With the spiropyran in the closed spiro isomeric form, FRET occurs freely between PB and A488. UV-induced isomerization to the open merocyanine form shuts down the F...

In this tutorial review, the most recent developments in the field of molecular logic and information processing are discussed. Special emphasis is given to the report of progress in the concatenation of molecular logic devices and switches, the design of memory systems working according to the principles of sequential logic, the mimicking of trans...