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Chirality plays a fundamental role in natural phenomena, yet its manifestation on solid surfaces remains relatively unexplored. In this study, we investigate the formation of chiroptical melanin‐based self‐assembled films on quartz substrates, leveraging mussel‐inspired surface chemistry. Water‐soluble porphyrins serve as molecular synthons, facilitating the spontaneous formation of hetero‐aggregates in phosphate‐buffered saline containing L‐ or D‐DOPA. Spectroscopic analysis reveals chiral transfer from DOPA enantiomers to porphyrin hetero‐aggregates, followed by the disruption of these latter and subsequent generation of chiral melanin structures in solution. Quartz substrates inserted into these solutions spontaneously accumulate homogeneous melanin‐like films over days, demonstrating the feasibility of self‐assembly. The resulting films exhibit characteristic UV/Vis and CD spectra, with distinct signals indicating successful chiral induction. Interestingly, the AFM characterizations reveal a distinct surface morphology, and in addition, some thermal and mechanical properties have been taken into account. Overall, this study sheds light on the formation, stability, and chiroptical properties of melanin‐based films, paving the way for their application in various fields. [ABSTRACT FROM AUTHOR]

In this work, we have characterized the interactions of monospermine porphyrin derivative with calf thymus DNA (ct‐DNA) and poly (dG‐dC)2 in both B and Z conformation. By several spectroscopic techniques (UV–vis, electronic circular dichroism and resonance light scattering), the binding modes of monospermine porphyrin derivative with different DNA sequences have been elucidated. In the presence of ct‐DNA, the porphyrin binds along the external double helix as well as in the presence of B conformation of poly (dG‐dC)2. Whilst when the Z form of the poly (dG‐dC)2 is induced, a slight intercalation of the porphyrin between the basis has been detected. [ABSTRACT FROM AUTHOR]

Porphyrinoids are extremely attractive for their electronic, optical, and coordination properties as well as for their versatile substitution at meso/β-positions. All these features allow porphyrinoids to behave as chiroptical hosts for chiral recognition by means of non-covalent interactions towards chiral guests. Over the years, chiral discrimination of chiral molecules such as amino acids, alcohols, amines, hydroxy-carboxylic acids, etc. has aroused the interest of the scientific community. Hence, this review aims to report on the progress to date by illustrating some relevant research regarding the chiral recognition of a multitude of chiral organic guests through several chiral mono- and bis-porphyrins via different spectroscopic techniques. [ABSTRACT FROM AUTHOR]

Antibiotics represent essential drugs to contrast the insurgence of bacterial infections in humans and animals. Their extensive use in livestock farming, including aquaculture, has improved production performances and food safety. However, their overuse can implicate a risk of water pollution and related antimicrobial resistance. Consequently, innovative strategies for successfully removing antibiotic contaminants have to be advanced to protect human health. Among them, photodegradation TiO2-driven under solar irradiation appears not only as a promising method, but also a sustainable pathway. Hence, we evaluated several composite TiO2 powders with H2TCPP, CuTCPP, ZnTCPP, and SnT4 porphyrin for this scope in order to explore the effect of porphyrins sensitization on titanium dioxide. The synthesis was realized through a fully non-covalent functionalization in water at room conditions. The efficacy of obtained composite materials was also tested in photodegrading oxolinic acid and oxytetracycline in aqueous solution at micromolar concentrations. Under simulated solar irradiation, TiO2 functionalized with CuTCPP has shown encouraging results in the removal of oxytetracycline from water, by opening the way as new approaches to struggle against antibiotic's pollution and, finally, to represent a new valuable tool of public health. [ABSTRACT FROM AUTHOR]

The dispersion of para-nitroaniline (p-NA) in water poses a threat to the environment and human health. Therefore, the development of functional adsorbents to remove this harmful compound is crucial to the implementation of wastewater purification strategies, and electrospun mats represent a versatile and cost-effective class of materials that are useful for this application. In the present study, we tested the ability of some polyethersulfone (PES) nanofibers containing adsorbed porphyrin molecules to remove p-NA from water. The functional mats in this study were obtained by two different approaches based on fiber impregnation or doping. In particular, meso-tetraphenyl porphyrin (H2TPP) or zinc(II) meso-tetraphenyl porphyrin (ZnTPP) were immobilized on the surface of PES fiber mats by dip-coating or added to the PES electrospun solution to obtain porphyrin-doped PES mats. The presence of porphyrins on the fiber surfaces was confirmed by UV–Vis spectroscopy, fluorescence measurements, and XPS analysis. p-NA removal from water solutions was spectrophotometrically detected and evaluated. [ABSTRACT FROM AUTHOR]

We report of the interactions between four amino acids lysine (Lys), arginine (Arg), histidine (His), and phenylalanine (Phe) with the J-aggregates of the protonated 5,10,15,20-tetrakis(4-sulfonatophenyl)-porphyrin H4TPPS. Several aspects of these self-assembled systems have been analyzed: (i) the chiral transfer process; (ii) the hierarchical effects leading to the aggregates formation; and, (iii) the influence of the amino acid concentrations on both transferring and storing chiral information. We have demonstrated that the efficient control on the J-aggregates chirality is obtained when all amino acids are tested and that the chirality transfer process is under hierarchical control. Finally, the chiral porphyrin aggregates obtained exhibit strong chiral inertia. [ABSTRACT FROM AUTHOR]

The functionalization of carbon dots with dyes by exploiting supramolecular interactions represents a huge resource in nanomaterials science. Desired properties, and especially the optical ones, can be obtained starting from the knowledge of surface-related interactions, which can be exploited to originate the complex. In this context, the present work explores the photophysical properties of supramolecular complexes, spontaneously formed, in the water medium, by the interaction of the anionic meso-tetrakis(4-sulfonatophenyl) porphyrin (TPPS 4) with three different fluorescent carbon nanodots (CNDs). The results of UV–vis, steady-state and time-resolved fluorescence experiments show that the formation of porphyrin/carbon dot adducts is favoured if nanodot surface charge is high enough to ensure electrostatic attraction of the porphyrin, and the resulting emission properties depend on the surface precursor as well. In such adducts, both species undergo fluorescence quenching through non-radiative mechanisms such as electron transfer, making these nanomaterials economic candidates for applications in energy conversion or sensor field. [Display omitted] [ABSTRACT FROM AUTHOR]