Absorption Of Organic Molecules Research Articles

Effect of activated carbon compaction on water filtration efficiency

Water contamination in rural Malaysian areas, mainly caused by logging activities leading to soil erosion and river pollution, presents a significant threat to water supplies. In response, a specialized activated carbon water filtering device was developed to target the absorption of organic molecules. The impact of compaction of activated carbon on water filtering efficiency was evaluated. Testing both compacted and uncompacted activated carbon filters with contaminated river water, the study utilized the Malaysia Department of Environment’s (DOE) water quality index (WQI) to assess filter effectiveness. The results revealed that water filtered through compacted activated carbon was clearer and less yellowish compared to the uncompacted counterpart. Moreover, the compacted filter showed higher dissolved oxygen levels, lower ammoniacal nitrogen levels, and a lower pH, resulting in a significantly higher WQI score of 80.4 compared to 78.8 for the uncompacted filter. Further analysis via an adsorption isotherm test demonstrated the superior ability of compacted activated carbon to absorb acetic acid, as evidenced by higher lines in the Freundlich isotherm model graphs. These findings emphasize the efficacy of compacted activated carbon in water filtration, advocating for its integration into filter construction to enhance water quality in rural regions.

Orientation Dependent Interlayer Coupling in Organic–Inorganic Heterostructures

AbstractOrganic–inorganic 2D heterostructures combine the high optical absorption of organic molecules with exciton‐dominated optical properties in layered transition metal dichalcogenides (TMDs) such as MoS2. Critical to the interaction and the optical response in such hybrid systems is the electronic band alignment at the interface between the two species. Here, the coupling of monolayers of perylene derivatives is investigated with bilayer MoS2. In particular, variation in the perylene orientation on the MoS2 surface is identified using Raman spectroscopy and scanning probe microscopy. Low‐temperature optical spectroscopy reveals orientation‐dependent interlayer exciton formation. Furthermore, power‐dependent photoluminescence measurements provide insight into the modified interlayer charge transfer in these heterostructures. A saturation of interlayer states is found under high excitation power when the perylene molecules are in a perpendicular orientation to the surface that leads to electron accumulation in the MoS2, whereas parallel alignment of the perylene molecules leads to enhanced populations of organic–inorganic interlayer excitons. This work provides insights into the optimization of organic–inorganic heterostructures, with particular relevance to applications for optoelectronic and excitonic devices.

Study of two-photon absorption and excited-state dynamics of coumarin derivatives: the effect of monomeric and dimeric structures.

Intramolecular charge transfer (ICT) and π-electron delocalization are two key factors affecting the nonlinear optical absorption of organic molecules. To clarify the different influences of ICT and π-electron delocalization on two-photon absorption (TPA) and excited-state absorption (ESA), monomeric coumarin C1 and dimeric coumarin C2 are synthesized and studied. Transient absorption spectroscopy (TAS) analysis of these coumarin derivatives in solvents of varying polarities describes the polarity-dependent excited-state dynamics and reveals the ESA signals of the charge transfer state (CTS) and local excited state (LES) with different spectral features. Femtosecond broadband Z-scan experiments indicate that dimeric coumarin C2 has a more significant TPA response than monomeric coumarin C1 in the near-infrared region. Natural transition orbital (NTO) analysis further theoretically characterizes the electron transition feature induced by TPA. Our results reveal that the TPA of these coumarin derivatives can be significantly enhanced by expanding π-electron delocalization, but their ESA is mainly dominated by ICT performance. This study indicates that coumarin derivatives will exhibit extremely broad application prospects in the field of ultrafast optical limiting (OL) through reasonable molecular design.

Physicochemical and functional properties of canaryseed (Phalaris canariensis L.) with and without spicules flour

AbstractBackground and ObjectiveGlabrous canaryseed flour is a novel ingridient with potential uses in the food industry. The objective of this study was to characterize and compare the physicochemical and functional properties of canaryseed (Phalaris canariensis L.) flours of the glabrous (without spicules) CDC Togo variety (whole and white flour, T and TW, respectively) and a traditional commercial variety (CW, white flour).FindingsScanning electron microscopy of the grains showed the glabrous nature of the T variety and the spicules present in the C variety. All the flours showed a high protein content (16.16%–25.49% dry basis [d.b.]), color tending to yellowish tones, and a predominant lipophilic behavior (oil‐holding capacity > water‐holding capacity). Dehulling of the CDC Togo seeds significantly altered some of the flour's properties. Particle size decreased by 23%, and protein and oil contents were 43% and 26% higher, respectively. TW flour also had a significantly lower color saturation, water‐holding capacity, oil‐holding capacity, water‐absorption capacity, and organic molecule absorption capacity when compared to T flour.ConclusionsThe results indicate the potential use of canaryseed grains as a raw material for novel food products.Significance and NoveltyThis study presents novel data on the properties of canaryseed flour of the glabrous CDC Togo variety, about which no information has been found. As well as on canaryseed flour from a traditional (nonglabrous) variety.

Antenna-enhanced mid-infrared detection of extracellular vesicles derived from human cancer cell cultures

BackgroundExtracellular Vesicles (EVs) are sub-micrometer lipid-bound particles released by most cell types. They are considered a promising source of cancer biomarkers for liquid biopsy and personalized medicine due to their specific molecular cargo, which provides biochemical information on the state of parent cells. Despite this potential, EVs translation process in the diagnostic practice is still at its birth, and the development of novel medical devices for their detection and characterization is highly required.ResultsIn this study, we demonstrate mid-infrared plasmonic nanoantenna arrays designed to detect, in the liquid and dry phase, the specific vibrational absorption signal of EVs simultaneously with the unspecific refractive index sensing signal. For this purpose, EVs are immobilized on the gold nanoantenna surface by immunocapture, allowing us to select specific EV sub-populations and get rid of contaminants. A wet sample-handling technique relying on hydrophobicity contrast enables effortless reflectance measurements with a Fourier-transform infrared (FTIR) spectro-microscope in the wavelength range between 10 and 3 µm. In a proof-of-principle experiment carried out on EVs released from human colorectal adenocarcinoma (CRC) cells, the protein absorption bands (amide-I and amide-II between 5.9 and 6.4 µm) increase sharply within minutes when the EV solution is introduced in the fluidic chamber, indicating sensitivity to the EV proteins. A refractive index sensing curve is simultaneously provided by our sensor in the form of the redshift of a sharp spectral edge at wavelengths around 5 µm, where no vibrational absorption of organic molecules takes place: this permits to extract of the dynamics of EV capture by antibodies from the overall molecular layer deposition dynamics, which is typically measured by commercial surface plasmon resonance sensors. Additionally, the described metasurface is exploited to compare the spectral response of EVs derived from cancer cells with increasing invasiveness and metastatic potential, suggesting that the average secondary structure content in EVs can be correlated with cell malignancy.ConclusionsThanks to the high protein sensitivity and the possibility to work with small sample volumes—two key features for ultrasensitive detection of extracellular vesicles- our lab-on-chip can positively impact the development of novel laboratory medicine methods for the molecular characterization of EVs.Graphical

Microwave-ultrasound assisted extraction of red corn pigments and their effect on chemical composition and tecno-functional properties

Currently, there is a growing interest in obtaining natural pigments, without presenting a risk to health, as well as to the matrix and food safety. The objective of this study was to characterize grains with different shades of red color (High pigmentation maize = RA, Medium pigmentation maize = RM, and Low pigmentation maize = RB, reddish maize with white segments = VO and white maize control = SC). The physical properties (kernel weight, length, width, thickness, and grain and flour color), chemical composition (moisture, fat, protein, fiber, starch, ash, and minerals), and techno-functional properties (capacity of absorption of organic molecules (OMAC), swelling (CH), oil retention (CAAC), and water absorption (WAS)) variables were measured. Afterward, RM was selected, and a pigment extraction (EAUM) was carried out using microwave-ultrasound equipment with different ratios of ethanol (0, 30, and 70%) and citric acid ratios (0 and 1%). The color and properties of the solid (starch, protein, fat, and their techno-functional properties) were determined in the aqueous phase and were compared with the properties prior to EAUM. The results indicated that the red grains have higher starch content (57.6%) and reddish colors, in addition, VO presented higher moisture (10.4%), fat (6.7%) and fiber (10.0%). The colors of the pigments obtained with EtOH (30 and 70%) show shades red and yellow. Finally, the EAUM decreased the fat content up to 57%, increased WAS and CAAC in the residual flour and generated changes in OMAC and CH, increasing in aqueous medium and reducing with EtOH.

Physicochemical and Functional Properties of Pumpkin Seed Flour of <em>Cucurbita maxima</em> and <em>Cucurbita moschata</em> Species

Pumpkin seeds are rich source of nutrients and beneficial bioactive compounds. In Sri Lanka, pumpkin seeds are discarded without being used. Physicochemical characteristics of seeds and functional properties of pumpkin seed flour (PSF) of two varieties of <em>Cucurbita maxima </em>(Suprema and <em>Bingha F1</em>) and one variety of <em>Cucurbita moschata </em>(<em>Padma</em>) were determined. Seeds collected from each variety were subjected to different treatments before preparation of PSF: roast at 80-90°C for 15 min, germinate and dry at 50-60°C for 4h, and dry at 50-60°C for 4h as the control, prior to prepare PSF. Antioxidant activity, total phenolic, total flavonoids and flour properties such as water holding capacity (WHC), swelling capacity (SC), oil holding capacity (OHC), emulsion stability (ES), organic molecule absorption capacity (OMAC)) of nine types of PSF were determined. A sensory evaluation (Hedonic scale) was conducted to determine the effect of 25, 50 and 75% substitution with PSF in biscuit production. The variety × treatment interaction effect was significant (p&lt;0.05) for WRC, OHC, SC and OMAC but not for WHC and ES. Germinated and dried PSF of the Suprema variety possessed the highest WHC (6.31±0.16 g/g), OHC (3.23± 0.07 g/g) and SC (6.00±0.28 mL/g) while the highest antioxidant activity (90.06±0.24%) and flavonoid content (19.87±1.08 mg QE/g) were observed in germinated dried seeds of <em>Bingha F1 </em>variety PSF. In roasted PSF, the highest phenolic content (1.52±0.02 mg GAE/g) was in <em>Bingha F1 </em>variety. Substitution with 25% PSF was selected as the optimum level in formulation of biscuit with the acceptable sensory attributes. Hence, PSF possesses a high potential as a source of functional food ingredient in the food manufacturing industry.

Mucuna pruriens fiber: nutritional, functional and biological properties

An evaluation was done of the nutritional, functional and antioxidant properties of fiber residues from Mucuna pruriens bean. Nutritional value was quantified in terms of proximate composition, total dietary fiber (TDF), insoluble dietary fiber (IDF), soluble dietary fiber (SDF) and the Van Soest fiber components. Functional value was assayed by measuring water holding capacity (WHC), oil holding capacity (OHC), water absorption capacity (WAbC), water adsorption capacity (WAdC) and organic molecule absorption capacity (OMAC). Emulsifying capacity was also studied. Biological potential was identified by measuring antioxidant properties, as well as phenols and flavonoids content. Nutritionally, M. pruriens fiber registered 26% of raw fiber, 77.65% TDF, 69.40% IDF and 8.25% SDF. Van Soest fiber components were 61.35% acid detergent fiber (ADF), 66.86% neutral detergent fiber (NDF) and 13.62% acid detergent lignin (ADL). Cellulose and hemicellulose content were 47.73 and 5.51%, respectively. Fiber functional potential values were 3.24 g/g sample for WHC, 1.65 for OHC, 3.61 for WAbC, 0.24 for WAdC and 1.19 for OMAC. The highest emulsifying capacity was registered at pH 4. Antioxidant activity was observed in assays as reducing power, DPPH and ABTS•+, being possibly attributed to components as phenols (2624.80 μg of gallic acid equivalents/mg), and flavonoids (232.71 μg catechin equivalents/mg), quantified at 20mg/mL.

Rational synthesis of ZnO decorated Fe hierarchical nanostructures for enhanced photocatalytic performance by long-pulse-width laser ablation of binary alloys target

Abstract Here we present a facile approach for the controllable synthesis of multifunctional ZnO decorated Fe hierarchical nanostructures, including ZnO quantum dots (QDs) decorated Fe nanowires, flocky Fe@ZnO core-shell nanospheres (Fe@ZnO CSNSs), ZnO nanospindles cluster on Fe core. The various hierarchical nanostructures composed of ZnO and unstable Fe nanoparticles (NPs) were successfully prepared in large scale via long-pulse-width millisecond laser ablation of Fe/Zn alloy target with suitable molar ratio immersed in anhydrous ethanol solution at room temperature and room pressure. In particular, the formation mechanism of flocky Fe@ZnO core-shell nanospheres (Fe@ZnO CSNSs) under laser ablation in liquid that constructed by unstable nanophase Fe core and stable phase ZnO QDs were proposed. As for the formation of such nanostructure, the condensation of Fe and Zn from the homogeneous metal nanodroplets after long-pulse-width laser ablation resulted in the first formation of unstable nanophase Fe core due to their huge gap in melting point. Then the subsequent diffusion and solidification of Zn atoms and oxidization process of Zn in the liquid media lead to the appearance of ZnO QDs outside the Fe core. The Fe@ZnO CSNSs were further used for the photocatalytic degradation of aromatic dye Rhodamine B (RhB). The results show that the Fe@ZnO CSNSs display quite good performance on the photocatalytic degradation of the RhB molecules under natural light irradiation with a power density around 100 mW/cm2 at 25 °C. The photocatalytic reduction of RhB is about 66.1%, 89.8%, and 94.1% after natural light irradiation for 5 min, 10 min and 20 min, respectively. The effective separation of photogenerated carriers due to the unique structure and absorption of organic molecules in the Fe@ZnO CSNSs together enhances the photocatalytic activity in the degradation of RhB. These multifunctional Fe@ZnO CSNSs present a promising potential for the removal of aromatic dye in wastewater and other catalytic applications.

Between Aromatic and Quinoid Structure: A Symmetrical UV to Vis/NIR Benzothiadiazole Redox Switch.

Reversibly switching the light absorption of organic molecules by redox processes is of interest for applications in sensors, light harvesting, smart materials, and medical diagnostics. This work presents a symmetrical benzothiadiazole (BTD) derivative with a high fluorescence quantum yield in solution and in the crystalline state and shows by spectroelectrochemical analysis that reversible switching of UV absorption in the neutral state, to broadband Vis/NIR absorption in the 1st oxidized state, to sharp band Vis absorption in the 2nd oxidized state, is possible. For the one‐electron oxidized species, formation of a delocalized radical is confirmed by electron paramagnetic resonance spectroelectrochemistry. Furthermore, our results reveal an increasing quinoidal distortion upon the 1st and 2nd oxidation, which can be used as the leitmotif for the development of BTD based redox switches.

Measurements of Entangled Two-Photon Absorption in Organic Molecules with CW-Pumped Type-I Spontaneous Parametric Down-Conversion

Entangled photons exhibit strong nonclassical frequency and time correlations simultaneously, which allow them to excite and extract information about molecules in new ways compared to classical sp...

Isolation and functional caharacterization of chia (Salvia hispanica) proteins

Abstract The objective was to isolate and characterize the proteins of chia seeds cultivated in the Mexican southeast. The main protein fraction was glutelins (42.94%) that had the highest Water Absorption Capacity (WAbC). Prolamins had the highest Water Adsorption Capacity (WAdC) (1.83 g/g). Glutelins registered the highest Water Holding Capacity (WHC). A higher Oil Holding Capacity (OHC) of chia protein fractions was registered in globulins and a higher Organic Molecule Absorption Capacity (OMAbC) was registered in albumin fractions (5.5 g/g of sample). At pH 2, 4 and 6, the glutelins registered a higher Emulsifying Capacity (EC) while, at pH 8 and 10, the prolamins recorded a higher EC percentage. Chia fractions registered the highest Foam Capacity (FC) values at pH 8 for globulins and pH 2 for albumins, prolamins and glutelins. Foaming and emulsifying stability (FS and ES) was greatly influenced by pH.

Functionality of Agave Bagasse as Supplement for the Development of Prebiotics-Enriched Foods.

Agave bagasse is a fibrous-like material obtained during aguamiel extraction, which is also in contact with indigenous microbiota of agave plant during aguamiel fermentation. This plant is a well-known carrier of the prebiotic fructan-type carbohydrates, which have multiple ascribable health benefits. In the present work, the potential of ashen and green agave bagasse as functional ingredients in supplemented cookies was studied. For its application, the chemical, functional, properties of agave bagasses and formulated cookies were evaluated, as well as the physical properties of cookies. Chemical characterization was carried out by the proximate analysis of both bagasses and cookies, besides, the analysis of oligosaccharides was made by thin-layer chromatography and high-performance anion-exchange chromatography. In the same way, functional properties such as oil holding capacity, organic molecule absorption capacity, swelling capacity, and water holding capacity were analyzed in both agave bagasses and supplemented cookies. Finally, modifications in color and texture due to bagasse addition was studied through an analysis of total color difference and a penetrometric test, respectively. In this sense, ashen and green agave bagasses demonstrated chemical and functional properties for use in the food industry, since they increased oil holding capacity of cookies and transferred prebiotic fructooligosaccharides to both agave bagasse formulations, which remain active as a prebiotic ingredient in cookies after in vitro digestion and cookie manufacture, including thermal treatment. Hence, agave bagasse could be considered a valuable alternative for the addition of the nutritionally-relevant dietary fiber in healthier foods.

Organic Molecule‐Driven Polymeric Actuators

Front Cover: In article number 1800896, John W. C. Dunlop, Jiayin Yuan, and co-workers give an overview of how polymeric materials can be actuated through the absorption of organic molecules. Through the introduction of relatively simple design elements, such as controlling crystallinity or by introducing low-dimensional reinforcement, polymeric actuators can be programed to display complex macroscopic motions, with potential applications in sensing and smart systems.

Honeycomb-like TiO2@GO nanocomposites for the photodegradation of oxytetracycline

TiO2/RGO composite was synthesized via a low-temperature solvothermal method using graphene oxide (GO) as a precursor of graphene and TiCl4 as precursor of TiO2. A large number of TiO2 nanoflakes composed of nanoparticles are perpendicular to graphene sheet, and cross-linked by facade to self-assemble honeycomb-like spatial configuration. These porousare benefit for the absorption of organic molecules, and composite configuration holds the excellent carrier conductivity of graphene facilitating the rapid separation of photogenerated electron-hole pair. This composite shows high absorption of natural light in almost all bands, displaying better photocatalytic degradation activity for antibiotics OTC under man-made natural light than neat TiO2.

Salinity Effects on the Adsorption of Nucleic Acid Compounds on Na-Montmorillonite: a Prebiotic Chemistry Experiment.

Any proposed model of Earth's primitive environments requires a combination of geochemical variables. Many experiments are prepared in aqueous solutions and in the presence of minerals. However, most sorption experiments are performed in distilled water, and just a few in seawater analogues, mostly inconsistent with a representative primitive ocean model. Therefore, it is necessary to perform experiments that consider the composition and concentration of dissolved salts in the early ocean to understand how these variables could have affected the absorption of organic molecules into minerals. In this work, the adsorption of adenine, adenosine, and 5'AMP onto Na+montmorillonite was studied using a primitive ocean analog (4.0Ga) from experimental and computational approaches. The order of sorption of the molecules was: 5'AMP > adenine > adenosine. Infrared spectra showed that the interaction between these molecules and montmorillonite occurs through the NH2 group. In addition, electrostatic interaction between negatively charged montmorillonite and positively charge N1 of these molecules could occur. Results indicate that dissolved salts affect the sorption in all cases; the size and structure of each organic molecule influence the amount sorbed. Specifically, the X-ray diffraction patterns show that dissolved salts occupy the interlayer space in Na-montmorillonite and compete with organic molecules for available sites. The adsorption capacity is clearly affected by dissolved salts in thermodynamic terms as deduced by isotherm models. Indeed, molecular dynamic models suggest that salts are absorbed in the interlamellar space and can interact with oxygen atoms exposed in the edges of clay or in its surface, reducing the sorption of the organic molecules. This research shows that the sorption process could be affected by high concentration of salts, since ions and organic molecules may compete for available sites on inorganic surfaces. Salt concentration in primitive oceans may have strongly affected the sorption, and hence the concentration processes of organic molecules on minerals.

Enhancing light absorption in organic semiconductor thin films by one-dimensional gold nanowire gratings

The interaction of metallic plasmonic nanostructures and organic semiconductor thin films plays a crucial role in engineering light harvesting and energy transfer processes, e.g., for optoelectronic applications. Plasmonic resonances of the metal structures can be used to increase the light emission or absorption of organic molecules. Here small molecules are employed since they can form organic layers with a defined crystalline order and orientation of the transition dipole. Extinction measurements combined with numerical simulations of a hybrid system consisting of a gold nanowire grating and a thin film of diindenoperylene (DIP) are reported. The experimental results are compared to the simulations and indicate an enhanced absorption in the wavelength region corresponding to the transition from the highest occupied molecular orbital to the lowest unoccupied molecular orbital of DIP. This enhancement is found to be related to the localized field enhancement near the individual nanostructures as well as to grating-induced effects. Notably, the hybrid system also exhibits parallel lattice resonances, which have recently been discussed for two-dimensional (2D) gold nanostructure arrays. In this study a hybrid plasmonic-organic small molecule system exhibiting these modes is investigated. The results for this model system show a way to modify the optical properties of plasmonic nanostructures by collective effects to achieve stronger light-matter interaction in a wide range of hybrid plasmonic systems.

Delayed Triplet-State Formation through Hybrid Charge Transfer Exciton at Copper Phthalocyanine/GaAs Heterojunction.

Light absorption in organic molecules on an inorganic substrate and subsequent electron transfer to the substrate create so-called hybrid charge transfer exciton (HCTE). The relaxation process of the HCTE states largely determines charge separation efficiency or optoelectronic device performance. Here, the study on energy and time-dispersive behavior of photoelectrons at the hybrid interface of copper phthalocyanine (CuPc)/p-GaAs(001) upon light excitation of GaAs reveals a clear pathway for HCTE relaxation and delayed triplet-state formation. According to the ground-state energy level alignment at the interface, CuPc/p-GaAs(001) shows initially fast hole injection from GaAs to CuPc. Thus, the electrons in GaAs and holes in CuPc form an unusual HCTE state manifold. Subsequent electron transfer from GaAs to CuPc generates the formation of the triplet state in CuPc with a few picoseconds delay. Such two-step charge transfer causes delayed triplet-state formation without singlet excitation and subsequent intersystem crossing within the CuPc molecules.

Optical properties and photoinduced aggregation of cyanine dyes on silver island films

The optical properties and photoinduced modification of hybrid nanostructures, which are silver island films coated with a layer of cyanine dye, were studied. Experiments were conducted on three dye homologs and films differing in the equivalent thickness of the deposited silver. It was shown that the absorption of a hybrid film is not the sum of the absorption of the molecular layer and the plasmon absorption of the silver. The near fields of nanoparticles (NPs) that form island films increase the absorption of organic molecules, with the greatest increase observed in the band of J-aggregates. The influence of the near fields can be reduced by distancing the molecules from the NPs using an insulating polymer layer. In the presence of silver NPs, the photoinduced modification of the component composition of the layers of the dyes occurs at far lower energy densities. Resonant nanosecond laser pulses lead to the aggregation of molecules in hybrid films.

Nutritional composition in the chia seed and its processing properties on restructured ham-like products

Low-fat meat products always have harder texture, lower juiciness, and worse flavor. Due to their higher water-holding, water absorption, and organic molecule absorption, chia seeds (CHIA) have been applied in powders, nutrition bars, breads, and cookies. Hence, the objectives of this study were to: (1) analyze the nutritional compositions in CHIA; and (2) look for the possible application of CHIA on restructured ham-like products. CHIA has high amounts of α-linolenic acid, crude polysaccharides, and also contains essential amino acids, minerals, and polyphenols. Regarding processing properties of CHIA, a combination of CHIA and carrageenan (CA) increased (p<0.05) production yield of restructured ham-like products. A scanning electron microscope observation indicated that CHIA and CA addition can assist an emulsification in this ham-like product. Addition of 0.5% CA and 1.0% CHIA in this ham-like product showed the similar overall acceptance as products with added fat. Following storage at 4°C, higher (p<0.05) purge and centrifugation losses, as well as hardness of this ham-like product can be improved by adding CHIA and CA. CHIA addition also resulted in lower (p<0.05) lipid and protein oxidation, especially a 1.0% addition. In summary, due to both nutritional addition and improvements on physicochemical and sensorial properties of restructured ham-like products, CHIA seeds have great potential on the development of healthy and good-quality meat products.