Detection of Pathogenic Bacteria in Milk and Whey Samples using A Fluorescence Resonance Energy Transfer Aptasensor based on Cerium Oxide Nanoparticles

Herein, we present a facile and sensitive fluorescence resonance energy transfer (FRET) aptasensor for detection of pathogenic bacteria, where Antibiotic-functionalized cerium oxide nanoparticles were served as an energy donor and...

Elongation of Triplet Lifetime Caused by Intramolecular Energy Hopping in Diphenylanthracene Dyads Oriented to Undergo Efficient Triplet–Triplet Annihilation Upconversion

Triplet–triplet annihilation (TTA)-assisted photon upconversion (TTA-UC) in three dyads (DPA–Cn–DPA), comprised of two diphenylanthracene (DPA) moieties connected by nonconjugated C1, C2, and C3 linkages (Cn), has been investigated. The performance of these dyads as energy acceptors in the presence of the energy donor platinum octaethylporphyrin are characterized by longer triplet lifetimes (<i>τ</i>_T) and different TTA rate constants than those of the parent DPA. The larger <i>t</i>_T of the linked systems, caused by “Intramolecular Energy Hopping” in the triplet dyad ³DPA*–Cn–DPA, results in a low threshold intensity, a key characteristic of efficient TTA-UC.

Optical-switchable energy transfer controlled by multiple-responsive turn-on fluorescence via metal–ligand and host–guest interactions in diarylethene-based [2]pseudo-rotaxane polymers

Multi-responsive and optically-active diarylethene (DAE)-based [2]pseudo-rotaxane polymers were prepared via host–guest interactions of Zn2+ coordinated with two terpyridyl ligands bearing crown-ethers as an energy donor host and DAE containing two ammonium salts as an acceptor guest.

In situ formation of photoactive B-ring reduced chlorophyll isomer in photosynthetic protein LH2

Natural chlorophylls have a D-ring reduced chlorin π-system; however, no naturally occurring photosynthetically active B-ring reduced chlorins have been reported. Here we report a B-ring reduced chlorin, 17,18-didehydro-bacteriochlorophyll (BChl) a, produced by in situ oxidation of B800 bacteriochlorophyll (BChl) a in a light-harvesting protein LH2 from a purple photosynthetic bacterium Phaeospirillum molischianum. The regioselective oxidation of the B-ring of B800 BChl a is rationalized by its molecular orientation in the protein matrix. The formation of 17,18-didehydro-BChl a produced no change in the local structures and circular arrangement of the LH2 protein. The B-ring reduced 17,18-didehydro-BChl a functions as an energy donor in the LH2 protein. The photoactive B-ring reduced Chl isomer in LH2 will be helpful for understanding the photofunction and evolution of photosynthetic cyclic tetrapyrrole pigments.

Long-lived Triplet State Formation Caused by Intramolecular Energy Hopping in Diphenylanthracene Dyads Oriented to Undergo Efficient Triplet–Triplet Annihilation Upconversion

Triplet–triplet annihilation (TTA)-assisted photon upconversion (TTA-UC) in three dyads (DPA–Cn–DPA), comprised of two diphenylanthracene (DPA) moieties connected by nonconjugated C1, C2, and C3 linkages (Cn), has been investigated. The performance of these dyads as energy acceptors in the presence of the energy donor platinum octaethylporphyrin are characterized by longer triplet lifetimes (<i>τ</i>_T) and different TTA rate constants than those of the parent DPA. The larger <i>τ</i>_T of the linked systems, caused by “intramolecular energy hopping” in the triplet dyad ³DPA*–Cn–DPA, results in a low threshold intensity, a key characteristic of efficient TTA-UC.

Long-lived Triplet State Formation Caused by Intramolecular Energy Hopping in Diphenylanthracene Dyads Oriented to Undergo Efficient Triplet–Triplet Annihilation Upconversion

Triplet–triplet annihilation (TTA)-assisted photon upconversion (TTA-UC) in three dyads (DPA–Cn–DPA), comprised of two diphenylanthracene (DPA) moieties connected by nonconjugated C1, C2, and C3 linkages (Cn), has been investigated. The performance of these dyads as energy acceptors in the presence of the energy donor platinum octaethylporphyrin are characterized by longer triplet lifetimes (<i>τ</i>_T) and different TTA rate constants than those of the parent DPA. The larger <i>τ</i>_T of the linked systems, caused by “intramolecular energy hopping” in the triplet dyad ³DPA*–Cn–DPA, results in a low threshold intensity, a key characteristic of efficient TTA-UC.

Aptamer-modified sensitive nanobiosensors for the specific detection of antibiotics

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.