A ratiometric fluorescence strategy based on polyethyleneimine surface-modified carbon dots and Eosin Y for ultrasensitive determination of protamine and trypsin.

In this work, we established a novel and ultrasensitive dual-signal fluorescence emission detection system of protamine and trypsin based on the electrostatic interaction between polyethyleneimine (PEI) surface-modified positively charged carbon...

Exploring Eosin Y as a Bimodular Catalyst: Organophotoacid Mediated Minisci-Type Acylation of N-Heteroarenes

Here we report the Eosin Y as a bimodular catalyst for Minisci-type acylation reaction. The formation of an organic exciplex between photoexcited Eosin Y and N-heteroarene was found to be...

Experimental and theoretical observations of alkylated EOSIN based “turn-on” superoxide sensor as well as its anti-microbial study

The alkylating as well as alkoxylating behavior of dialkyl sulfites are well presented in the literature. In the present work dialkyl sulphites behavior has been investigated towards EOSIN Y (tetrabrominated fluorescein). The products of the reactions (dialkylated eosin Y) reveal that alkylation takes place at the both active sites (at hydroxyl and carboxyl functionalities) in a single step through sulphur-centred Arbuzov type rearrangement. Density functional theory (DFT) has been used as a tool to analyze the role of the halogen groups present at the periphery of the xanthene moiety in alkylation at hydroxyl and carboxy positions of EOSIN Y. Furthermore, in photo-physical study, it was observed that compound C acts as a superoxide sensor specifically with the detection limit 63μM. Its anti-microbial activity was checked against the E. coli and S-aureus using the agar well diffusion assay and, it was observed that it could be used as better antimicrobial agent.

AN EFFECTIVE BIOSORBENT DERIVED N EFFECTIVE BIOSORBENT DERIVED FROM PRODUCTION WASTE ROM PRODUCTION WASTE FOR WATER TREATMENT: STUDYING OR WATER TREATMENT: STUDYING THE ADSORPTION OF SYNTHETIC DYES HE ADSORPTION OF SYNTHETIC DYES

Introduction. Eco-friendly disposal of food waste, in particular, nutshells and fruit kernels, is an important issue to ensure sustainable nature management. These secondary raw materials are the source of valuable polymeric materials, cellulose and lignin.Problem Statement. IGiven the capacity of the food industry in Ukraine and the amount of waste produced, the development of technologies for processing lignin-cellulose biomass is an important research and practical issue.Purpose. The purpose of this research is to study the adsorption properties of chemically modified biosorbent based on plant materials concerning synthetic dyes of different types and classes; to assess the feasibility of biosorbent production and efficiency of its application in water treatment.Materials and Methods. Lignocellulose sorbent (LCS) has been synthesized from non-wood raw materials by chemical modification with the use of phosphoric acid with the addition of urea in an aqueous media. The Fourier transform infrared and standard methods of plant raw material analysis have been used to determine the physicochemical characteristics of LCS. The adsorption of anionic (methyl orange, alizarin red S, eosin Y), cationic (methylene blue, neutral red), and nonionic (aniline yellow) dyes on LCS from aqueous solution has been studied in the batch mode.Results. The adsorption capacity of LCS towards cationic dyes (47.0–53.3 mg/g) is higher than that of anionic (22.2–36.9 mg/g) and nonionic (4.7 mg/g) ones. The adsorption kinetics have been adequately described by a pseudo-second-order equation. Adsorption of all classes of dyes on LCS is thermodynamically feasible, spontaneous, and endothermic process. The liquid by-product of LCS production contains 15% nitrogen and 10% phosphorus, so it may be used as a fertilizer. Conclusions. The proposed method for processing food waste provides obtaining effective sorbent and liquid NP-fertilizer. LCS removes both cationic and anionic pollutants from water, so it may be considered a promisingbiosorbent for water purification.

Cotton Fabric Modified with a PAMAM Dendrimer with Encapsulated Copper Nanoparticles: Antimicrobial Activity

A new methodology for modifying textile materials with dendrimers containing nanoparticles was developed. This involved a combination of eosin Y and N-methyldiethanolamine (MDEA) for reducing the copper ions in the dendrimer complex by enabling a photochemical reaction under visible light and ambient conditions. The conversion of copper ions into nanoparticles was monitored using scanning electron microscopy (SEM) and by performing colorimetric, fluorescence, and electron paramagnetic resonance (EPR) studies. Regardless of the concentration of the photoinitiator eosin Y, it discolored completely upon illumination. Three types of cotton fabrics were compared as antimicrobial materials against Bacillus cereus. One of the fabrics was dyed with a first-generation PAMAM dendrimer which had been functionalized with eight 1,8-naphthalimide fluorophores. Another fabric was dyed with a dendrimer–copper complex, and the third was treated by conversion of the complex into copper nanoparticles encapsulated into the dendrimer. An enhancement in the antimicrobial activity of the textiles was achieved at higher dendrimer concentrations, under illumination with visible light. The fabric modified with the copper nanoparticles encapsulated inside the dendrimer exhibited the best antibacterial activity because it had two photosensitizers (PS), as both 1,8-naphthalimide fluorophores and copper nanoparticles were contained in the dendrimer molecules. The presence of oxygen and suitable illumination activated the photosensitizers to generate the reactive oxygen species (singlet oxygen (1O2) and other oxygenated products, e.g., anion radicals, hydroxyl radicals, and hydrogen peroxide) responsible for destroying the bacteria.

Systematic optimization of visible light-induced crosslinking conditions of gelatin methacryloyl (GelMA)

Gelatin methacryloyl (GelMA) is one of the most widely used photo-crosslinkable biopolymers in tissue engineering. In in presence of an appropriate photoinitiator, the light activation triggers the crosslinking process, which provides shape fidelity and stability at physiological temperature. Although ultraviolet (UV) has been extensively explored for photo-crosslinking, its application has been linked to numerous biosafety concerns, originated from UV phototoxicity. Eosin Y, in combination with TEOA and VC, is a biosafe photoinitiation system that can be activated via visible light instead of UV and bypasses those biosafety concerns; however, the crosslinking system needs fine-tuning and optimization. In order to systematically optimize the crosslinking conditions, we herein independently varied the concentrations of Eosin Y [(EY)], triethanolamine (TEOA), vinyl caprolactam (VC), GelMA precursor, and crosslinking times and assessed the effect of those parameters on the properties the hydrogel. Our data showed that except EY, which exhibited an optimal concentration (~ 0.05 mM), increasing [TEOA], [VA], [GelMA], or crosslinking time improved mechanical (tensile strength/modulus and compressive modulus), adhesion (lap shear strength), swelling, biodegradation properties of the hydrogel. However, increasing the concentrations of crosslinking reagents ([TEOA], [VA], [GelMA]) reduced cell viability in 3-dimensional (3D) cell culture. This study enabled us to optimize the crosslinking conditions to improve the properties of the GelMA hydrogel and to generate a library of hydrogels with defined properties essential for different biomedical applications.

Divergent functionalization of aldehydes photocatalyzed by neutral eosin Y with sulfone reagents

While aldehydes represent a classic class of electrophilic synthons, the corresponding acyl radicals are inherently nucleophilic, which exhibits umpolung reactivity. Generation of acyl radicals typically requires noble metal catalysts or excess oxidants to be added. Herein, we report a convenient and green approach to access acyl radicals, capitalizing on neutral eosin Y-enabled hydrogen atom transfer (HAT) photocatalysis with aldehydes. The generated acyl radicals underwent SOMOphilic substitutions with various functionalized sulfones (X–SO2R’) to deliver value-added acyl products. The merger of eosin Y photocatalysis and sulfone-based SOMOphiles provides a versatile platform for a wide array of aldehydic C–H functionalizations, including fluoromethylthiolation, arylthiolation, alkynylation, alkenylation and azidation. The present protocol features green characteristics, such as being free of metals, harmful oxidants and additives; step-economic; redox-neutral; and amenable to scale-up assisted by continuous-flow technology.