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To advance our understanding of the molecular biochemistry of fungi which impact cultural heritage in libraries, museums and archives we investigated the diagnostic capacity of Raman spectroscopy to identify the composition of colored chromophores of fungi on paper. In this study we explored the diagnostic capacity of resonant Raman to distinguish chromophores in fungal filaments stimulated to grow on paper under high humidity with a focus on characterizing chromophores of Alternaria group species. To facilitate molecular analysis, we conducted quantum chemistry calculations of representative metabolites having optical absorption in the ultraviolet–visible spectral range. Comparing theory and experiment we show that fonsecin, erythroglaucin and aurasperone type chromophores occur in mature hyphal filaments with β-carotene dominant in yeast depositions on paper surfaces. Resonant Raman of mature filaments suggests a further contribution of carotenes longer than β-carotene to the spectral signature. Using microscopic resolution, we distinguish rich sets of Raman signatures that we assign to lignin, flavoglaucin, riboflavin, cycloleucomelon(e) and asperyellone molecular components in the spatial regions where filaments initiate from yeast depositions. In such regions, where filament microstructures stimulate development of a mature three-dimensional scaffold, the diversity of Raman resonances confirms a rich biochemistry of the developing structures. The library of computed optical and spectroscopic responses of characteristic fungal chromophores and metabolites presented here is essential for understanding the effect of fungi on a wide range of objects made from paper including books, prints, drawings, watercolors, engravings and even sculptures as well as designing next generation materials based on fungal hyphal mats. • Non-invasive Raman spectroscopy can be used to identify pigments in fungi. • Quantum chemistry (DFT) combined with Raman for quantitative measure of chromophores. • Computed optical responses of fungal chromophores and metabolites. • Raman spectroscopy combined with Quantum chemistry as tools for cultural heritage. • Alternaria sp. generates specific pigments when grown on paper. [ABSTRACT FROM AUTHOR]

Paper-based diagnostic assay is quite popular in point-of-care testing (POCT). In this work, we reported a series of hybrid fluorophores based on fluorescein derivatives and investigated their fluorescent properties in detail. To extend the practical application of these hybrid fluorophores, we further constructed the corresponding probes (FN1-FN4) for Cu2+ detection. In comparison with the other three probes, FN4 showed high selectivity and sensitivity, as well as response to Cu2+ within 20 min. Particularly, by introducing this probe into the paper-based device, we could achieve simple, high-throughput, visual and highly sensitive platform for POC detection of Cu2+. Finally, we assessed the paper-based device in real samples such as serum, cytochylema and lake water to demonstrate its promising application. As a result, satisfied performance for Cu2+ detection was achieved, which indicates the great potential of our strategy in the construction of POCT system for detecting analytes. Image 1 • Novel hybrid fluorophores based naphthofulorescein dyes have been synthesized to show excellent fluorescence properties. • Hybrid fluorophores-based paper device for visual detection of Cu2+ has been developed. • Suitable for point-of-care detection, the paper device could visualize high-throughput Cu2+ detection in real samples. [ABSTRACT FROM AUTHOR]

(E)-Stilbene hydrophobic fluorophores possessing long perfluorinated or hydrocarbonated chains have been prepared through a stereoselective Wittig-Schlosser reaction. When covalently grafted upon paper, they give rise to a fluorescent-labeled paper upon irradiation with UV light. The hydrophobicity and oleophobicity of the fluorous (E)-stilbene derivative furnish self-cleaning properties. Application in the detection of money counterfeiting is envisioned. Image 1 • A new family of fluorescent (E)-stilbene derivatives have been prepared in a real simple and straightforward way. • The fluorescent (E)-stilbene derivatives were covalently grafted upon paper giving rise to a photochromic paper. • The hydrophobicity and oleophobicity of the fluorous (E)-stilbene derivative furnish self-cleaning properties. • This approach can have a real application in the detection of counterfeited paper money. [ABSTRACT FROM AUTHOR]