Herein, we report the design and synthesis of two naphthalene diimide amphiphiles
NDI-TA1
and
NDI-TA2
bearing acylated and deacylated hydroxyl groups of tartaric acid, respectively. Furthermore, we ...investigated the influence of acylation and deacylation of hydroxyl groups of tartaric acid over UV-vis, aggregation induced emission (AIE), chirality and supramolecular self-assembly formation. A bottom-up supramolecular self-assembly formation approach of the
NDI-TA1
amphiphile exhibited biomimetic hairy caterpillar-like superstructures in a THF/MCH 30 : 70 v/v solvent system, whereas long uniform helical ribbons were also yielded at a higher volume percentage of MCH in THF (90 : 10 v/v). Circular dichroism (CD) spectroscopy studies revealed a chiral aspect of the self-assembled supramolecular structures at wavelengths corresponding to their absorptions. Interestingly,
NDI-TA1
aggregates at higher amounts of MCH in THF exhibited AIE properties because of excimer formation. On the other hand, the
NDI-TA2
amphiphile displays total quenching of emission,
i.e.
the aggregation cause quenching (ACQ) effect. The SEM images of deacylated amphiphile
NDI-TA2
show belt and sheet-like supramolecular self-assembled microstructures.
Herein, we report the design, synthesis and self-assembly of two naphthalene diimide amphiphiles
NDI-TA1
and
NDI-TA2
bearing acylated and deacylated hydroxyl groups of tartaric acid, respectively.
Supramolecular self-assembly and self-organization are simple and convenient ways to design and create controlled assemblies with organic molecules, and they have provoked great interest due to their ...potential applications in various fields, such as electronics, photonics, and light-energy conversion. Herein, we describe the synthesis of two π-conjugated porphyrin molecules bearing tetraphenylethene moieties with high fluorescence quantum yield. Photophysical and electrochemical studies were conducted to understand the physical and redox properties of these new materials, respectively. Furthermore, these derivatives were used to investigate self-assembly via the solvophobic effect. The self-assembled aggregation was performed in nonpolar and polar organic solvents and forms nanospheres and ring-like nanostructures, respectively. The solution based aggregation was studied by means of UV–vis absorption, emission, XRD, and DLS analyses. Self-assembled ring-shape structures were visualized by SEM and TEM imaging. This ring-shape morphology of nanosized macromolecules might be a good candidate for the creation of artificial light-harvesting nanodevices.
Nanoparticles play a vital role in modern agriculture to provide the nutrients required by plants. Herein, we report the preparation of calcium-doped zinc oxide nanoparticles (CZO NPs) via a simple ...and cost-effective co-precipitation method, with the aim of realizing increased fertilizer response. The synthesized nanoparticles were analyzed to study their physicochemical properties using various characterization techniques. The X-ray diffraction pattern showed a small shift in peak position towards higher values of 2θ and reduced crystal size after the zinc oxide (ZnO) matrix had been doped with Ca. Field-emission scanning electron microscopy images clearly revealed a grain-like surface morphology. The X-ray photoelectron spectroscopy study produced evidence of Zn2+ substitution by Ca2+ and enhanced Zn–O bond strengths in the CZO samples. Two major crops, maize (Zea mays L.) and wheat (Triticum aestivum L.) were selected to study the impact of the CZO NP-based nanofertilizer on plant growth. During the study, the effect of the CZO-based fertilizer on growth parameters such as seed germination, root and shoot length, plant height, root and stem width, number of leaves, and leaf size was studied based on comparisons with control plants. We observed significantly increased plant growth parameters after the application of the CZO NP-based fertilizers.
•Ca-doped ZnO nanoparticle-based fertilizer.•Impact of different concentrations of calcium in ZnO matrix as a fertilizer.•Impact on seed germination, root and shoot length, plant height, root and stem width, number of leaves, and leaf size.•Significant enhancement in the growth parameters of plants.
A new pyrene-phosphonate colorimetric receptor 1 has been designed and synthesized in a one-step process via amide bond formation between pyrene butyric acid chloride and phosphonate-appended ...aniline. The pyrene-phosphonate receptor 1 showed aggregation-induced enhanced emission (AIEE) properties in water/acetonitrile (ACN) solutions. Dynamic light scattering (DLS) characterization revealed that the aggregates of receptor 1 at 80% water fraction have an average size of ≈142 nm. Field emission scanning electron microscopy (FE-SEM) analysis confirmed the formation of spherical aggregates upon solvent evaporation. The sensing properties of receptor 1 were investigated by UV-vis, fluorescence emission spectroscopy, and other optical methods. Among the tested metal ions, receptor 1 is capable of recognizing the Fe3+ ion selectively. The changes in spectral measurements were explained on the basis of complex formation. The composition of receptor 1 and Fe3+ ions was determined by using Job’s plot and found to be 1:1. The receptor 1–Fe3+ complex showed a reversible UV-vis response in the presence of EDTA.
Quinoxaline-based novel acid-responsive probe
was designed on the basis of a conjugated donor-acceptor (D-A) subunit.
shows colorimetric and fluorometric changes through protonation and deprotonation ...in dichloromethane. With the addition of the trifluoroacetic acid (TFA), UV-vis absorption spectral changes in peak intensity of
was observed. Moreover, the appearance of a new peaks at 284 nm 434 nm in absorption spectra with the addition of TFA indicating protonation of quinoxaline nitrogen and form
and
. The emission spectra display appearance of new emission peak at 515 nm. The optical property variations were supported by time resolved fluorescence studies. The energy band gap was calculated by employing cyclic voltammetry and density functional calculations. Upon addition of triethylamine (TEA) the fluorescence emission spectral changes of
are found to be reversible.
shows color changes from blue to green in basic and acidic medium, respectively. The paper strip test was developed for making
a colorimetric and fluorometric indicator.
Although chemical structural modification of naphthalimides is widely employed for the purpose of sensing explosives, the effects of such modification have been little explored. Herein, we report the ...design and synthesis of a new naphthalimide-benzothiazole conjugate (1) and its ability to sense various nitrophenols by means of its colorimetric and fluorescent characteristics. Under long-range UV light (365 nm), 1 displayed a color change of its solution from bluish to colorless only upon addition of 2,4,6-trinitrophenol (TNP). Photoluminescence spectroscopy showed quantitative fluorescence quenching by TNP of the emission peaks of 1 at 398 nm and 418 nm due to donor–acceptor electron transfer. The interaction of 1 with TNP was via a cooperative, non-covalent hydrogen-bonding interaction. Receptor 1 exhibited high sensitivity and selectivity towards TNP over various aromatic nitro analytes. The binding constant (K) and Stern–Volmer constant (Ksv) between 1 and TNP were found to be 5.332 × 10−5 M and 2.271 × 106 M−1, respectively. Furthermore, the limit of detection was calculated and found to be as low as 1.613 × 10−10 M.
The ability to control interparticle forces not only improves the existing nanoparticle (NP) functionalities but paves the way for newer properties as well. A proof of concept in this direction is ...presented here, wherein the regulation of interparticle forcesrevealing controlled aggregationhas been successfully translated into the trapping and scavenging of toxic ions. A perfect balance between the attractive and repulsive forces is achieved by tuning the + and − ligands on the surface of heterogeneously charged metal NPs. The NP–ion aggregates are stable for ∼2 days, with a visible color change (Δλmax = 12–15 nm), which makes them available for scavenging from the site of action. The incorporation of “potent” forces like repulsions, rather than a mere dilution of attractive forces, is necessary to ensure the formation of controlled aggregates. The net surface charge of NPs is conveniently modified to trap ions irrespective of their charge and binding strength. More importantly, the regulation of interparticle forces imparts a new function of selectivity toward trapping of toxic ions in a carboxylate functionalized NP system. Thus, the present work introduces a conceptually unprecedented approach to impart long-term stability (∼2 days) to NP–ion aggregates by controlling the interparticle forces.
Highly crystalline photoactive Cu2ZnSnS4 (CZTS) thin films are fabricated by a simple and low cost spray-pyrolysis technique without sulfurization treatment in toxic atmosphere. The influence of ...substrate temperatures on the physico-chemical properties of the CZTS films is investigated. The film sprayed at optimized substrate temperature exhibits optical band gap energy of 1.49eV, which is prerequisite for the photovoltaic applications. The photoelectrochemical (PEC) device of CZTS-500 film showed a power conversion efficiency of 0.86% which is the highest efficiency for sprayed CZTS thin films so far.
•Synthesis of highly crystalline phase-pure CZTS thin films using a CSP technique without sulfurization treatment in toxic atmosphere.•Influence of growth temperatures on the properties of CZTS thin films.•Bandgap tunnelling is observed as a function of substrate temperature.•Power conversion efficiency of 0.86% which is the highest efficiency for sprayed CZTS thin films so far.
Overcoming the issue of the stability of tin‐based perovskites is a major challenge for the commercial development of lead‐free perovskite solar cells. To attack this problem, a new organic cation, ...azetidinium (AZ), is incorporated into the crystal structure of formamidinium tin triiodide (FASnI3) to form the mixed‐cation perovskite AZxFA1‐xSnI3. As AZ has a similar size to FA but a larger dipole moment, hybrid AZxFA1‐xSnI3 films exhibit variation in optical and electronic properties on increasing the proportion of AZ. Trifluoromethylbenzene (CF3C6H5) serves as antisolvent to fabricate smooth and uniform perovskite films for the devices with an inverted planar heterojunction structure. The device performance is optimized to produce the greatest efficiency at x=0.15 (AZ15), for which a power conversion efficiency of 9.6 % is obtained when the unencapsulated AZ15 device is stored in air for 100 h. Moreover, the device retains 90 % of its initial efficiency for over 15 days. The significant performance and stability of this device reveal that the concept of mixed cations is a promising approach to stabilize tin‐based perovskite solar cells for future commercialization.
Can we mix it? Yes we can! Mixing 15 % of azetidinium (AZ) inside a FASnI3 perovskite crystal enhances the device performance to attain a power conversion efficiency of 9.6 % with excellent stability for the unencapsulated device, which retains 90 % of its initial performance for over 15 days.
Early detection of asymptomatic cases through mass screening is essential to constrain the coronavirus disease 2019 (COVID-19) transmission. However, the existing diagnostic strategies are either ...resource-intensive, time-consuming, or less sensitive, which limits their use in the development of rapid mass screening strategies. There is a clear pressing need for simple, fast, sensitive, and economical diagnostic strategy for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) screening even in resource-limited settings. In the current work, we assessed the
feasibility of directly labeling virus surface proteins using fluorogenic molecules with aggregation-induced emission (AIE) property. Here, we present the results for binding of two such AIE probes, phosphonic acid derivative of tetraphenyl ethylene (TPE-P) and sulfonic acid derivative of tetraphenyl ethylene (TPE-S), to SARS-CoV-2 spike protein based on
docking studies. Our results show that both TPE-P and TPE-S bind to angiotensin converting enzyme 2 (ACE2)-binding, and N-terminal domains of SARS-CoV-2 spike protein. Molecular dynamic simulations have revealed specific nature of these interactions. We also show that TPE-P and TPE-S bind to hemagglutinin protein of influenza virus, but the interaction strength was found to be different. This difference in interaction strength may affect the emission spectrum of aforementioned AIE probes. Together, these results form a basis for the development of AIE-based diagnostics for differential detection of SARS-CoV-2 and influenza viruses. We believe that these
predictions certainly aid in differentially labeling of the both viruses toward the development of rapid detection by AIE probes.
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