Novel and durable lightening photoluminescent electrospun nanofibrous-walled tubes were developed with the ability to glow like a flashlight helping to replace electric power in medical endoscopes. Simple preparation of an organic–inorganic photoluminescent nanocomposite was developed via encapsulation of rare-earth doped aluminum strontium oxide nanoscaled particles into polycaprolactone-cellulose acetate-based nanofibers. The luminescent nanofibrous-walled tubes demonstrated an excitation band at 355 nm and a photostability phosphorescence band at 517 nm. The UV–vis absorbance and emission spectra and CIE Lab color space parameters demonstrated photochromic colorimetric shifting from white under visible daylight to greenish-yellow under ultraviolet light. Both mechanical and superhydrophobic properties of the nanocomposite electrospun nanofibrous-walled tubes were explored. The nanofibrous-walled tubes exhibited an enhanced hydrophobic performance without adversely influencing its inherent characteristics. The morphology and chemical structure of the prepared phosphor nanoparticles and the performance of the phosphorescent electrospun nanofibrous-walled tubes were explored. The cytotoxicity of the generated photoluminescent aluminum strontium oxide pigment was explored. The produced nanofibrous-walled tubes demonstrated photostable long-persistent photoluminescence without fatigue upon exposure to an external ultraviolet light source.

Acknowledging the need to develop rapid and sensitive bacterial recognition approaches, we functionalised the tricyanofuran hydrazone molecular switch. Of significant interest in relation to the synthesised hydrazones is the formation of two different conjugated structures upon exposure to different pH values. Many bacteria release ammonia gas, which alkalises environments. Herein we report the synthesis of a tricyanofuran hydrazone having the function of a colorimetric pH sensor. The UV-visible absorption and fluorescence spectra exhibit reversible colour changes of the tricyanofuran hydrazone solution in acetonitrile under acidbase conditions. Our results indicate that the tricyanofuran hydrazone probe can identify the bacterial targets quickly with high sensitivity. The infected samples exhibit a significant colour change from orange to blue and in the mean time there is a decrease in fluorescence emission as a function of ammonia and volatile amines released from bacterial metabolites. This tricyanofuran hydrazone chromophore is proposed for use in food packaging with a pH-sensing capability. Coloration TechnologySociety of Dyers and Colourists E T (30)solvent polarity parameter; eextinction coefficient; k max abs , nm -Maximum Absorption Wavelength; k max em , nm -Maximum Emission/ Fluorescence Wavelength.

Four novel tricyanofuran disperse dyestuffs 3a‐d bearing hydrazone moiety were synthesized in order to investigate their possible antibacterial activity. The hydrazone moiety was introduced via azo‐coupling of the tricyanofuran with the appropriately functionalized diazonium salt. The optical properties of these compounds showed interesting solvatochromic properties. The absorption peaks are observed in the wavelength range 454–513 nm. It can also be seen that they display different maximum emissions in the wavelength range 528–615 nm. The functional groups attached to the hydrazone moiety influenced both on absorption and emission maxima. The prepared hydrazone‐based disperse dyes were applied for dyeing polyester fabrics, affording satisfactory results. Furthermore, compounds 3a and 3c demonstrated a relatively strong antibacterial activity against some selected gram positive Staphylococcus aureus and Bacillus subtilis; and gram negative Escherichia coli and Pseudomonas aeuroginosa employing Ampicillin as standard drug.

Abstract:The present work describes the synthesis of a series of four novel biologically active 2-amino-5-arylazothiazole disperse dyes containing the sulfa drug nucleus. The structures of the synthesized thiazole derivatives are confirmed using UV-spectrophotometry, infrared and nuclear magnetic resonance techniques and elemental analysis. The synthesized dyes are applied to polyester fabrics as disperse dyes and their fastness properties to washing, perspiration, rubbing, sublimation, and light are evaluated. The synthesized compounds exhibit promising biological efficiency against selected Gram-positive and Gram-negative pathogenic bacteria as well as fungi.

Sulphonamide motifs are widely found in many drug candidates with relevant biological activity. Moreover, sulphonamide azo dyes are interesting candidates for synthetic chemists because such dyes provide access to a broad range of functional group transformations. Therefore, many synthetic procedures for the preparation of sulphonamide azo dyes have been developed in recent decades, and the search for rapid and efficient protocols is ongoing. The current article aims to review recent trends in the synthesis of sulphonamide azo dyes and their applications as high‐performance colorants with antimicrobial activity. For convenience, the diverse uses of sulphonamide azo dyes are discussed from the perspective of the application type rather than the structural class.