Multi-dye Systems Research Articles

Alginate-based porous polyHIPE for removal of single and multi-dye mixtures: Competitive isotherm and molecular docking studies

A novel hydrophilic porous alginate-based polyHIPE (AGA) was synthesized via an oil-in-water emulsion templating approach. AGA was used as an adsorbent for removing methylene blue (MB) dye in single- and multi-dye systems. BET, SEM, FTIR, XRD, and TEM were used to characterize AGA to elucidate its morphology, composition and physicochemical properties. According to the results, 1.25 g/L AGA adsorbed 99 % of 10 mg/L MB in 3 h in a single-dye system. The removal efficiency decreased to 97.2 % in the presence of 10 mg/L Cu2+ ions and 40.2 % when the solution salinity increased to 70 %. In a single-dye system, the experimental data do not match well with the Freundlich isotherm, pseudo-first order, and the Elovich kinetic model, however, in a multi-dye system, it fit well with both extended Langmuir and the Sheindorf-Rebhun-Sheintuch. Notably, AGA removed 66.87 mg/g in a dye solution containing only MB, whereas 50.14–60.01 mg/g adsorption of MB was accomplished in a multiple-dye system. According to the molecular docking analysis, the dye removal process involved chemical bonds between the functional groups of AGA and the dye molecules, hydrogen bonds, hydrophobic and electrostatic interactions. The overall binding score of MB decreased from −26.9 kcal/mol in a single-dye system to −18.3 kcal/mol in a ternary system.

Design and Development of Inexpensive Paper-Based Chemosensors for Detection of Divalent Copper

Simple, portable, and low-cost paper-based sensors are alternative devices that have the potential to replace high-cost sensing technologies. The compatibility of the paper base biosensors for both chemical and biochemical accentuates its feasibility for application in clinical diagnosis, environmental monitoring, and food quality monitoring. High concentration of copper in blood serum and urine is associated with diseases like liver diseases, carcinomas, acute and chronic infections, rheumatoid arthritis, etc. Detection of copper concentration can give an early sign of Alzheimer disease. Apart from that genetic Wilson's disease can be detected by evaluating the concentration of copper in the urine. In view of the above advantages, a novel and the highly sensitive paper-based sensor has been designed for the selective detection of Cu2+ ions. The fast and highly sensitive chemiresistive multi-dye system sensor can detect Cu2+ ions selectively in as low as 2.23 ppm concentration. Least interference has been observed for counter ion in the detection of Cu2+. Copper chloride, nitrate, and acetate were used to validate the detection process. This assay provides a very high selectivity of Cu2+ ion over other metal cations such as Na+, Mg2+, Ca2+, etc. The easy preparation and high stability of dye solutions, easy functionalization of the paper-based sensors, high selectivity over other cations, low interference of counter anion, and significantly low detection limit of 2.23 ppm make it an effective Cu2+ ion sensor for real-time application in near future.Graphical

Breath Analysis for the In Vivo Detection of Diabetic Ketoacidosis.

Human breath analysis of volatile organic compounds has gained significant attention recently because of its rapid and noninvasive potential to detect various metabolic diseases. The detection of ketones in the breath and blood is key to diagnosing and managing diabetic ketoacidosis (DKA) in patients with type 1 diabetes. It may also be of increasing importance to detect euglycemic ketoacidosis in patients with type 1 or type 2 diabetes or heart failure, treated with sodium-glucose transporter-2 inhibitors (SGLT2-i). The present research evaluates the efficiency of colorimetry for detecting acetone and ethanol in exhaled human breath with the response time, pH effect, temperature effect, concentration effect, and selectivity of dyes. Using the proposed multidye system, we obtained a detection limit of 0.0217 ppm for acetone and 0.029 ppm for ethanol in the detection range of 0.05–50 ppm. A smartphone-assisted unit consisting of a portable colorimetric device was used to detect relative red/green/blue values within 60 s of the interface for practical and real-time application. The developed method could be used for rapid, low-cost detection of ketones in patients with type 1 diabetes and DKA and patients with type 1 or type 2 diabetes or heart failure treated with SGLT2-I and euglycemic ketoacidosis.

Simultaneous degradation of anionic and cationic dyes from multi-dye systems using falling film photoreactor: performance evaluation, kinetic and toxicity analysis

In this investigation, performance evaluation of different advanced oxidation processes (AOPs) viz. UV, PS, HPO, PS + HPO, UV + PS, UV + HPO and UV + PS + HPO in falling film photoreactor (FFPR) for degradation of methyl orange (MO) and eosin yellow (EY) dye(s) in mono-dye (MO/EY) and multi-dye (MO + EY) systems were examined. Meanwhile, the derivative spectroscopic method was used to quantify the concentration of dye(s) in multi-dye mixture. Subsequently, the effect of experimental conditions such as the reaction time, dye concentration and oxidant dosage on dye(s) degradation was studied. Furthermore, kinetic study, LCMS and toxicity study were carried out to determine the rate constant, degradation pathway and % inhibition, respectively. From the results, it was found that the UV + PS + HPO system was effective in the removal of both dyes in mono-dye and multi-dye systems. A maximum removal of 100% and 97.9% was noticed for MO and EY dyes in mono-dye system, respectively. Meanwhile, a maximum removal of 88.9% and 100% was seen for MO and EY dyes from MO + EY multi-dye system. On the other hand, the toxicity was found to decline after 240 min and 300 min of UV irradiation during the degradation of EY and MO dyes, respectively. The synergistic index, energy consumption and electrical energy order of UV + PS + HPO system were better for removal of dyes from mono-dye and multi-dye systems when compared with other AOPs. In general, UV + PS + HPO system in FFPR can be efficiently applied for the simultaneous removal of multiple dyes.

Luminescent periodic mesoporous organosilicas

Progress in the development of periodic mesoporous organosilicas (PMOs) bearing luminescent organic groups is reviewed and directions for future research are highlighted. The inclusion of luminescent organic groups in the PMO framework allows for the preparation of materials with dissimilar luminescent groups in two spatially separated regions; the framework and the mesopore channels. Mesoporous silicas, in contrast, only bear luminescent dyes in the channels of the material structure. In multi-dye systems, the transfer of excitation energy from the framework donors to acceptors in the mesochannels is observed. Certain PMOs, such as biphenyl PMO, exhibit efficient light absorption due to the dense packing of chromophores in the framework, and high luminescence quantum yields, demonstrating the potential of luminescent PMOs as a lighting technology. Fluorescence studies have revealed that the interaction among bridging organic groups in PMOs differs between crystal-like and amorphous frameworks. These recent developments highlight the potential of luminescent PMOs as a new technology, which should be supported by further investigation of the optical properties and functionalization of PMOs.

DESIGN OF MULTIDYE SYSTEMS FOR FRET-BASED APPLICATIONS

A new solid phase approach, based on orthogonal protective group strategy utilizing Fmoc and DMTr groups, was used to assemble linear polymeric chains with pending groups at desired locations. A compound synthesized using four different fluorophores with consequently overlapping absorption and emission spectra (pyrene, perylene, fluorescein and TAMRA) was shown to fluoresce at 570 nm when excited at 330 nm, demonstrating sequential energy transfer across four chromophores.