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A more sustainable and efficient protocol for the photocatalytic α-amino arylation promoted by fac-Ir(ppy)3 was developed. Three noteworthy results were achieved: i) the replacement of toxic medium DMA with the greener solvents NBP and NHP, and the concurrent improvement of the process efficiency by lowering both the amine and the base amount; ii) the development of a recycling protocol for both the sustainable solvent NHP and the commercially available costly photocatalyst fac-Ir(ppy)3, achieving environmental and economic benefits. This approach to the photocatalyst recovery avoids very demanding catalyst structural modifications; iii) the protocol in green solvents proved to be scalable up to 10 mmol of limiting reagent, maintaining excellent performance also lowering the photocatalyst loading down to 0.05 mol%. This is the first example of photocatalytic α-arylation of amines promoted by such a low amount of catalyst. Lastly, the versatility of this approach was demonstrated by extending the use of the green solvent NBP to another photoredox process.

Bis-squaramide receptors L1–L4 bearing a dansyl moiety were considered as fluorescent probes for non steroidal antinflamatory drugs naproxene and ketoprofen.

Triamine-based receptors containing 2 anthracene units are able to signal ketoprofen in H2O/EtOH solution via fluorescence emission enhancement, exploiting a proton transfer process upon substrate coordination.

Over the past two decades, the chirality-induced spin selectivity (CISS) effect was reported in several experiments disclosing a unique connection between chirality and electron spin. Recent theoretical works have highlighted time-resolved Electron Paramagnetic Resonance (trEPR) as a powerful tool to directly detect the spin polarisation resulting from CISS. Because of the absence of interfaces with conducting electrodes, such spectroscopic evidence could provide a clear understanding of how CISS works at the intramolecular level. Experimental results have demonstrated the potential of this approach for detecting a spin-polarised photoinduced electron transfer (ET) in hybrid systems comprising a CdSe quantum dot as an electron donor (D) connected by a chiral linker (χ) to a fullerene derivative as an electron acceptor (A). However, the study of the ET process in fully organic D-χ-A dyads holds tremendous potential for the unambiguous detection of CISS. Here, we report a first attempt performed using novel D-χ-A dyads, comprising pyrene (D) and fullerene (A) connected by chiral saturated peptide bridges (χ) of different length and electric dipole moment. The dyads are investigated by an array of techniques, including cyclic voltammetry, optical spectroscopies, and trEPR. Despite the promising energy alignment of the electronic levels and the evidence of luminescence quenching, trEPR does not detect a significant ET highlighting the challenges of spectroscopic detection of CISS. However, the analysis allows the formulation of guidelines for the design of chiral organic model systems suitable to directly probe CISS-polarised ET.

A photoredox catalytic synthesis of functionalized 2-aminofurans is proposed starting from α-halo carbonyl substrates and N-allenamides. The protocol proves to be efficient and sustainable thanks to: i) the use of visible light as green energy source, ii) the redox-neutral nature of the transformation, allowing to avoid additives and strong oxidants, iii) the mild reaction conditions and the functional groups tolerance, iv) the low photocatalyst loading and the absence of excess reagents, v) the one-pot formation of three new bonds in a domino sequence. According to our mechanistic hypothesis, the transformation is configured as a double radical-polar crossover reaction, in which the photocatalyst is excited, oxidized and reduced twice for each molecule of 2-aminofuran produced. The novelty of the designed synthetic approach also lies in the use of N-allenamides as substrates, which, after the addition of the first electrophilic radical, preserve a further reactive π-system, making possible the addition of a second α-keto radical and enabling the installation of a keto functionality at a remote position. The good yields, the broad scope, and the possibility to further synthetically elaborate the obtained furans make this protocol particularly promising for the construction of useful products. (Figure presented.).

Real-time detection and nanoscale imaging of human immunodeficiency virus type 1 ribonucleic acid (HIV-1 RNA) in latently infected cells that persist in people living with HIV-1 on antiretroviral therapy in blood and tissue may reveal new insights needed to cure HIV-1 infection. Herein, we develop a strategy combining DNA nanotechnology and super-resolution expansion microscopy (ExM) to detect and image a 22 base sequence transcribed from the HIV-1 promoter in model live and fixed cells. We engineer a chimeric locked nucleic acid (LNA)-DNA sensor

Two synthetic routes for the preparation of the water soluble 5,10,15‐tris(4‐sulfonatophenyl)corrole are reported. The first approach explores the chlorosulfonation reaction on the phosphorus complex of 5,10,15‐tris(4‐trimethylsilylphenyl)corrole. Following this route, the P complex of the target corrole has been obtained in low yields, while the major product was the tetrasubstituted complex, with the additional sulfonyl group regioselectively introduced at the 2‐position. To widen the scope of the reaction, the direct preparation of the 5,10,15‐tris(4‐sulfonatophenyl)corrole has been pointed out, affording both the target corrole and the intermediate chlorosulfonyl derivative in reasonable yields. The photophysical properties and the protonation equilibria of both corroles have been investigated, showing that 5,10,15‐tris(4‐sulfonatophenyl)corrole does not aggregate in acidic solutions, different from the analogous porphyrin.

Protein aggregation is a phenomenon widespread in all organisms, that responds to a variety of external stimuli and is involved in complex functions such as storage and recycling of protein residues in crowded environments. In some cases, aggregation of proteins is related to serious human diseases. Understanding, monitoring and, eventually, intervening in the process of aggregation – in particular at its early stage – is a topic of high relevance and urgency. Recently, nanostructured materials have allowed for an unmet versatility and modularity in the field of sensing and inhibition of aggregation. Fluorescent oligomers and polymers, via controlled tuning of chemical functionalities, are yielding detailed comprehension of the interactions between probe candidates and protein aggregates; AIEgens are rapidly addressing many open challenges on sensitivity and signal enhancement; nanomaterials are increasingly serving as theranostic platforms, with multiple functionalities stemming from the assembly of components with complementary abilities. Here we review the most recent achievements in protein aggregation sensing based on macromolecular or nanostructured probes, highlighting the general experimental and computational findings that may serve as guidelines for the next generation of theranostic probes.

The synthesis of a new RuII complex, in which the metal is coordinated by two 1,10-phenanthroline ligands and a 2,2′-bipyridyl unit linked, via methylene bridges in its 4 and 4′ positions, to two 1,4,7,10-tetraazacyclododecane (cyclen) macrocycles ([Ru(phen)2L]2+) is reported. Protonation and ZnII binding by [Ru(phen)2L]2+ have been analyzed by potentiometric titration, evidencing the formation of mixed hetero-binuclear and hetero-trinuclear ZnII/RuII complexes. These complexes were tested as bis-phenol A (BPA) binders. Only the dizinc complex with [Ru(phen)2L]2+ is able to bind BPA in aqueous solution, affording a remarkably stable {Zn2[Ru(phen)2L]BPA(H−2)}4+ adduct at neutral pH, in which BPA is bound in its doubly deprotonated form to the two ZnII ions. BPA binding was found to quench the luminescence emission of the RuII(phen)2bipy core. Although the quenching effect is modest, this study demonstrates that appropriately designed dizinc complexes can be used for binding and optical sensing of BPA in water.