Low Compatibility Research Articles

Spotting priming-active compounds using parsley cell cultures in microtiter plates

BackgroundConventional crop protection has major drawbacks, such as developing pest and pathogen insensitivity to pesticides and low environmental compatibility. Therefore, alternative crop protection strategies are needed. One promising approach treats crops with chemical compounds that induce the primed state of enhanced defense. However, identifying priming compounds is often tedious as it requires offline sampling and analysis. High throughput screening methods for the analysis of priming-active compounds have great potential to simplify the search for such compounds. One established method to identify priming makes use of parsley cell cultures. This method relies on measurement of fluorescence of furanocoumarins in the final sample. This study demonstrates for the first time the online measurement of furanocoumarins in microtiter plates. As not all plants produce fluorescence molecules as immune response, a signal, which is not restricted to a specific plant is required, to extend online screening methods to other plant cell cultures. It was shown that the breathing activity of primed parsley cell cultures increases, compared to unprimed parsley cell cultures. The breathing activity can by monitored online. Therefore, online identification of priming-inducing compounds by recording breathing activity represents a promising, straight-forward and highly informative approach. However, so far breathing has been recorded in shake flasks which suffer from low throughput. For industrial application we here report a high-throughput, online identification method for identifying priming-inducing chemistry.ResultsThis study describes the development of a high-throughput screening system that enables identifying and analyzing the impact of defense priming-inducing compounds in microtiter plates. This screening system relies on the breathing activity of parsley cell cultures. The validity of measuring the breathing activity in microtiter plates to drawing conclusions regarding priming-inducing activity was demonstrated. Furthermore, for the first time, the fluorescence of the priming-active reference compound salicylic acid and of furanocoumarins were simultaneously monitored online. Dose and time studies with salicylic acid-treated parsley cell suspensions revealed a wide range of possible addition times and concentrations that cause priming. The online fluorescence measuring method was further confirmed with three additional compounds with known priming-causing activity.ConclusionsDetermining the OTR, fluorescence of the priming-active chemical compound SA and of furanocoumarins in parsley suspension cultures in MTPs by online measurement is a powerful and high-throughput tool to study possible priming compounds. It allows an in-depth screening for priming compounds and a better understanding of the priming process induced by a given substance. Evaluation of priming phenomena via OTR should also be applicable to cell suspensions of other plant species and varieties and allow screening for priming-inducing chemical compounds in intact plants. These online fluorescence methods to measure the breathing activity, furanocoumarin and SA have the potential to accelerate the search for new priming compounds and promote priming as a promising, eco-friendly crop protection strategy.

Discrete-modulation continuous-variable quantum key distribution with a high key rate

Discrete-modulation continuous-variable (CV) quantum key distribution has the potential for large-scale deployment in secure quantum communication networks owing to its low implementation complexity and compatibility with the current coherent optical telecommunication. However, current discrete-modulation protocols require relatively large constellation sizes to achieve a key rate comparable to that of the Gaussian modulation. Here, we show that a high key rate comparable to the Gaussian modulation can be achieved using only ten or so coherent states by implementing suitable key map and numerical convex optimization techniques. Specifically, the key rate of the two-ring constellation with 12 coherent states (four states in the inner ring and eight states in the outer ring) can reach 2.4 times of that of original quadrature phase shift keying and 70% of the Gaussian modulation protocol at 50 km. Such an approach can easily be applied to existing systems, making the discrete-modulation protocol an attractive alternative for high-rate and low-cost applications in secure quantum communication networks.

Investigation on the mechanical performance of mono-material vs multi-material interface geometries using fused filament fabrication

PurposeCurrently on additive manufacturing, extensive research is directed toward mitigating the main challenges associated with multi-material in fused filament fabrication which has a weak bonding strength between dissimilar materials. Low interfacial bonding strength leads to defects, anisotropy and temperature gradient in materials which negatively impact the mechanical performance of the multi-material prints. The purpose of this study was to assess the performance of different interface geometry designs in terms of the mechanical properties of the specimens.Design/methodology/approachTensile test specimens were printed using: mono-material without a boundary interface, mono-material with the interface geometries (Face-to-face; U-shape; T-shape; Dovetail; Encapsulation; Mechanical interlocking; and Overlap) and multi-material with the interface geometries. The materials chosen with high and low compatibility were Tough polylactic acid (PLA) and TPU.FindingsThe main results of this study indicate that the interface geometries with the mechanical constriction between materials provide better structural integrity to the specimens. Moreover, in the case of the mono-material parts, the most effective interface design was the mechanical interlocking for both Tough PLA and TPU. On the other hand, in the case of multi-material specimens, the encapsulation showed the highest ultimate tensile strength, whereas the overlap and T-shape presented more robust bonding.Originality/valueThis study examines the mechanical performance, particularly tensile strength, strain at break, Young’s modulus and yield strength of different interface designs which were not studied in the previous studies.

Highly Efficient Ternary Near-Infrared Organic Photodetectors for Biometric Monitoring.

Near-infrared (NIR) small-molecule acceptors that absorb at wavelengths of up to 1000 nm are attractive for applications in organic photodetectors (OPDs) and biometrics. In this study, we incorporated IEICO-4F as the third component for PffBT4T-2OD:PC71BM-based OPDs to provide an efficient NIR response while greatly suppressing the leakage current at reverse bias. By varying the blend ratio and thickness (250-600 nm), we obtained an NIR OPD displaying an ultralow dark-current density (JD = 2.62 nA cm-2), ultrahigh detectivity [D* = 7.2 × 1012 Jones (850 nm)], high sensitivity, and photoresponsivity covering the region from the ultraviolet to the NIR. We used tapping-mode atomic force microscopy, optical microscopy, grazing-incidence wide-angle X-ray scattering, and contact angle measurements to investigate the effect of IEICO-4F on the performance of the ternary OPDs. The low compatibility of PffBT4T-2OD and IEICO-4F, originating from weak intermolecular interactions, allowed us to manipulate the degree of phase separation between the donor and acceptor in the ternary blends, leading to an optimized blend morphology featuring efficient charge separation, transport, and collection. To demonstrate its applicability, we integrated our OPD with two light-emitting diodes and used the system for precisely calculated transmissive pulse oximetry.

Rootstock identity in melon-pumpkin graft combinations determines fruit metabolite profile.

Grafting has the potential to improve melon fruit yield and quality, but it is currently held that a lack of compatibility between the rootstock and scion compromises such an effect. To throw light on this subject, we studied melon-pumpkin graft combinations with different levels of compatibility to assess to the effect of the rootstock identity on melon fruit yield and quality, including total fruit ortho-diphenols, total flavonoids, and primary fruit metabolites. Melon cv. 'Kiran' (Ki) was grafted onto three pumpkin rootstocks, 'TZ-148' (TZ), 'Shimshon' (Sh), and '53006' (r53), characterized by high, moderate, and low compatibility, respectively. The non-grafted melon cultivar Ki was used as the control. The incompatible combination Ki/r53 gave the lowest fruit yield and the lowest average fruit weight. In that combination, the content of total ortho-diphenols increased vs. Ki and Ki/TZ and that of total flavonoids decreased vs. Ki/Sh. In addition, concentrations of the amino acids, glutamate, methionine, valine, alanine, glycine, and serine, increased in the pulp of the two compatible combinations, i.e., Ki/TZ and Ki/Sh, suggesting that rootstock identity and compatibility with melon Ki scion modulated amino acid synthesis. Our results show an association between rootstock identity (and level of compatibility with the scion) and an enhancement of fruit nutritional values, i.e., high concentrations of organic acids (determined as citrate, malate, fumarate, and succinate) and soluble carbohydrates (sucrose) were recorded in the pulp of the two compatible combinations, i.e., Ki/TZ and Ki/Sh.

Investigation of Advanced Oxidation Process in the Presence of TiO2 Semiconductor as Photocatalyst: Property, Principle, Kinetic Analysis, and Photocatalytic Activity

Water pollution is considered a serious threat to human life. An advanced oxidation process in the presence of semiconductor photocatalysts is a popular method for the effective decomposition of organic pollutants from wastewater. TiO2 nanoparticles are widely used as photocatalysts due to their low cost, chemical stability, environmental compatibility and significant efficiency. The aim of this study is to review the photocatalytic processes and their mechanism, reaction kinetics, optical and electrical properties of semiconductors and unique characteristics of titanium as the most widely used photocatalyst; and to compare the photocatalytic activity between different titania phases (anatase, rutile, and brookite) and between colorful and white TiO2 nanoparticles. Photocatalytic processes are based on the creation of electron–hole pairs. Therefore, increasing stability and separation of charge carriers could improve the photocatalytic activity. The synthesis method has a significant effect on the intensity of photocatalytic activity. The increase in the density of surface hydroxyls as well as the significant mobility of the electron–hole pairs in the anatase phase increases its photocatalytic activity compared to other phases. Electronic and structural changes lead to the synthesis of colored titania with different photocatalytic properties. Among colored titania materials, black TiO2 showed promising photocatalytic activity due to the formation of surface defects including oxygen vacancies, increasing the interaction with the light irradiation and the lifetime of photogenerated electron–hole pairs. Among non-metal elements, nitrogen doping could be effectively used to drive visible light-activated TiO2.

Highly efficient chitosan-based bio-polymeric membranes embedded with green solvent encapsulated MIL-53(Fe) for methanol/MTBE separation by pervaporation

An emerging family of solvents known as deep eutectic solvents has been heralded as a sustainable alternative to traditional solvents. Due to the low compatibility with polymeric materials, the direct use of a deep eutectic solvent (DES) as a solvent is still in the challenging phase. Therefore, we have developed a novel strategy to add DES into the polymer matrix. We have encapsulated MIL-53(Fe) using the choline chloride and ethylene glycol DES mixture and incorporated it into the chitosan polymer matrix. This study prepares chitosan-based biodegradable and sustainable membranes by adding different nanofillers such as DES, MIL-53(Fe), and DES@MIL-53(Fe) for methanol/MTBE azeotropic mixture separation. The prepared nanofillers and bio-degradable membranes are characterized using various analytical techniques such as FESEM, HRTEM, AFM, FTIR, XRD, TGA, XPS, mechanical strength, and wettability. The best separation results are found for the DES@MIL-53(Fe)/CS membranes because the membrane exhibit the characteristic of both components together. The highest total flux and methanol selectivity are observed for the F4 membrane, which is 2329 g m−2 h−1 and 207.06. Based on the surface characteristics and performance study, the DES@MIL-53(Fe)/CS membrane can have better potential in wastewater treatment and other membrane-based separation processes.

Tunable resins with PDMS-like elastic modulus for stereolithographic 3D-printing of multimaterial microfluidic actuators.

Stereolithographic 3D-printing (SLA) permits facile fabrication of high-precision microfluidic and lab-on-a-chip devices. SLA photopolymers often yield parts with low mechanical compliancy in sharp contrast to elastomers such as poly(dimethyl siloxane) (PDMS). On the other hand, SLA-printable elastomers with soft mechanical properties do not fulfill the distinct requirements for a highly manufacturable resin in microfluidics (e.g., high-resolution printability, transparency, low-viscosity). These limitations restrict our ability to print microfluidic actuators containing dynamic, movable elements. Here we introduce low-viscous photopolymers based on a tunable blend of the monomers poly(ethylene glycol) diacrylate (PEGDA, Mw ∼ 258) and the monoacrylate poly(ethylene glycol methyl ether) methacrylate (PEGMEMA, Mw ∼ 300). In these blends, which we term PEGDA-co-PEGMEMA, tuning the PEGMEMA content from 0% to 40% (v/v) alters the elastic modulus of the printed plastics by ∼400-fold, reaching that of PDMS. Through the addition of PEGMEMA, moreover, PEGDA-co-PEGMEMA retains desirable properties of highly manufacturable PEGDA such as low viscosity, solvent compatibility, cytocompatibility and low drug absorptivity. With PEGDA-co-PEGMEMA, we SLA-printed drastically enhanced fluidic actuators including microvalves, micropumps, and microregulators with a hybrid structure containing a flexible PEGDA-co-PEGMEMA membrane within a rigid PEGDA housing. These components were built using a custom "Print-Pause-Print" protocol, referred to as "3P-printing", that allows for fabricating high-resolution multimaterial parts with a desktop SLA printer without the need for post-assembly. SLA-printing of multimaterial microfluidic actuators addresses the unmet need of high-performance on-chip controls in 3D-printed microfluidic and lab-on-a-chip devices.

Ferroelectric synaptic devices based on CMOS-compatible HfAlOx for neuromorphic and reservoir computing applications.

The hafnium oxide-based ferroelectric tunnel junction (FTJ) has been actively researched because of desirable advantages such as low power and CMOS compatibility to operate as a memristor. In the case of HfAlOx (HAO), the remanent polarization (Pr) value is high and the atomic radius of Al is smaller than that of Hf; therefore, ferroelectricity can be better induced without mechanical force. In this paper, we propose an FTJ using HAO as a ferroelectric layer through electrical analysis and experiments; further, we experimentally demonstrate its capability as a synaptic device. Moreover, we evaluate the maximum 2Pr and TER value of the device according to the difference in conditions of thickness and cell area. The optimized device conditions are analyzed, and a large value of 2Pr (>∼43 μC cm-2) is obtained. Furthermore, we show that paired-pulse facilitation, paired-pulse depression, and spike-timing-dependent plasticity can be utilized in HAO-based FTJs. In addition, this study demonstrates the use of an FTJ device as a physical reservoir to implement reservoir computing. Through a series of processes, the synaptic properties of FTJs are verified for the feasibility of their implementation as an artificial synaptic device.

Dielectric and energy storage properties of surface-modified BaTi0.89Sn0.11O3@polydopamine nanoparticles embedded in a PVDF-HFP matrix.

In the most recent electronic and electric sectors, ceramic-polymer nanocomposites with high dielectric permittivity and energy density are gaining popularity. However, the main obstacle to improving the energy density in flexible nanocomposites, besides the size and morphology of the ceramic filler, is the low interfacial compatibility between the ceramic and the polymer. This paper presents an alternative solution to improve the dielectric permittivity and energy storage properties for electronic applications. Here, the poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) matrix is filled with surface-modified BaTi0.89Sn0.11O3/polydopamine nanoparticles (BTS11) nanoparticles, which is known for exhibiting multiphase transitions and reaching a maximum dielectric permittivity at room temperature. BTS11 nanoparticles were synthesized by a sol-gel/hydrothermal method at 180 °C and then functionalized by polydopamine (PDA). As a result, the nanocomposites exhibit dielectric permittivity (εr) of 46 and a low loss tangent (tan δ) of 0.017 at 1 kHz at a relatively low weight fraction of 20 wt% of BTS11@PDA. This is approximately 5 times higher than the pure PVDF-HFP polymer and advantageous for energy storage density in nanocomposites. The recovered energy storage for our composites reaches 134 mJ cm-3 at an electric field of 450 kV cm-1 with a high efficiency of 73%. Incorporating PDA-modified BTS11 particles into the PVDF-HFP matrix demonstrates highly piezo-active regions associated with BTS11 particles, significantly enhancing functional properties in the polymer nanocomposites.

Impact of NaCl concentration in crystalline nanocellulose for printed ionic dielectrics

While electronics continue to be an integral part of nearly every aspect of our lives, there is a growing need for more environmentally friendly electronic materials and manufacturing processes. The use of crystalline nanocellulose (CNC) as a biodegradable dielectric material has recently gained interest due to its high capacitance at low voltages and compatibility with additive manufacturing techniques, such as printing. The addition of salt to the CNC has shown improved performance in transistor applications, but a thorough study optimizing the addition of NaCl in CNC capacitors has not been completed. We hypothesized that increasing the NaCl concentration altered the charging characteristics of the CNC. In this work, we verified this hypothesis by measuring the charging and discharging characteristics for CNC capacitors with varying NaCl concentrations and extracting the resistance-capacitance (RC) delay and charging current. These aerosol jet printed capacitors consisted of graphene top and bottom electrodes and a CNC dielectric sandwiched between the electrodes. The results reveal a minimum charging current at a NaCl concentration of 0.05%, independent of the applied voltage, and a minimized RC delay at NaCl concentrations above 0.1% with applied voltages below 2 V. These findings show that there are trade-offs that must be managed between RC delay and charging current, thus the NaCl concentration must be optimized for each application. This work is another significant step in understanding the electrical properties of CNC so that this environmentally friendly material may one day be utilized in commercially available electronics.

Novel selenium and/or copper substituted hydroxyapatite-gelatin-chitosan-eggshell membrane nanocomposite scaffolds for bone tissue engineering applications.

Limitations with the majority of bone therapeutic treatments include low availability, ethical constraints and low biological compatibility. Although a number of choice materials have been exploited successfully, there has always been scope for improvement as well as development of the next-generation of materials. Herein, scaffolds - developed from gelatin, chitosan and eggshell membranes - were crosslinked using tannic acid, and further infused with selenium and/or copper substituted hydroxyapatite nanoparticles to generate a novel nanocomposite substrate. FESEM images of the nanocomposite scaffolds revealed the presence of interconnected pores, mostly spread over the whole surface of the scaffold, alongside XRD and FTIR profiling that detailed the formation of hydroxyapatite as a sole phase. Moreover, physical characterisation of the nanocomposite confirmed that the hydroxyapatite particulates and the eggshell membrane fibres were uniformly distributed and contributed to the surface roughness of the scaffold. Biocompatibility and cytotoxicity of the novel constructs were assessed using the mouse-derived osteoblastic cell line, MC3T3-E1, and standard cell culture assays. Metabolic activity assessment (i.e. MTS assay), LDH-release profiles and Live/Dead staining demonstrated good cell adhesion, viability, and proliferation rates. Accordingly, this work summarises the successful development of a novel construct which may be exploited as a clinical/therapeutic treatment for bone repair as well as a possible translational application as a novel biomaterial for the drug development pipeline.

Process-Based Crop Modeling for High Applicability with Attention Mechanism and Multitask Decoders.

Crop models have been developed for wide research purposes and scales, but they have low compatibility due to the diversity of current modeling studies. Improving model adaptability can lead to model integration. Since deep neural networks have no conventional modeling parameters, diverse input and output combinations are possible depending on model training. Despite these advantages, no process-based crop model has been tested in full deep neural network complexes. The objective of this study was to develop a process-based deep learning model for hydroponic sweet peppers. Attention mechanism and multitask learning were selected to process distinct growth factors from the environment sequence. The algorithms were modified to be suitable for the regression task of growth simulation. Cultivations were conducted twice a year for 2 years in greenhouses. The developed crop model, DeepCrop, recorded the highest modeling efficiency (= 0.76) and the lowest normalized mean squared error (= 0.18) compared to accessible crop models in the evaluation with unseen data. The t-distributed stochastic neighbor embedding distribution and the attention weights supported that DeepCrop could be analyzed in terms of cognitive ability. With the high adaptability of DeepCrop, the developed model can replace the existing crop models as a versatile tool that would reveal entangled agricultural systems with analysis of complicated information.

The Pacific Alliance: Towards a Model of Sustainable Development

The four countries that make up the Pacific Alliance, Chile, Colombia, Mexico and Peru, have experienced, in recent years, considerable economic development, reducing the poverty rate and increasing life expectancy. However, this progress has been accompanied by an economic dependence on extractive sectors, with high social and environmental costs, coupled with a steady increase in unsustainable patterns of consumption and production, which emphasizes the pressure on natural resources and the environment. In this regard, the Pacific Alliance has expressed its commitment to promote green economies as an alternative to continue with their economic and social development, managing their natural resources in more sustainable ways. Likewise, at present, sustainable development is a central focus in the full and effective recognition of people. The reasons for creating this new group have two perspectives. The first being geopolitical, meaning that the Pacific Alliance is a response to what is called, “a left turn” by some Latin American governments. The second is an economic perspective in which the Alliance appears as a new open regional scheme which strives towards perfecting the free trade zone comprised of the four countries. From the political perspective, the Alliance would appear to create a counterbalance to Mercosur, but it does not have the institutional structure and the ability to convene that the others have been able to develop. From the economic perspective, the growth and stability that is observed among the four members of the Alliance are its best aspects and serious obstacles still exist that need to be overcome in order to transcend the integration phase, of most importance being the low compatibility of customs in the presence of third parties which make it almost impossible to have in the short term a common regional market in that area. For this purpose, an analysis of the public policies of the Member States will be conducted, focusing mainly on national strategies against climate change, biodiversity, consumption and sustainable production, thus including national green growth plans.

Utilization of waste heat energy of exhaust gases in a diesel engine using the ORC system

Waste heat recovery systems using the organic Rankine cycle (ORC systems) can be a way to increase the overall efficiency of internal combustion engines (ICE) and way to reduce the emission to the environment. The main two advantages of ORC systems are: the use of thermal energy, which is dissipated into the environment in the form of heat - fuel energy, which is not used by the ICE and the lack of interference in the operation of the ICE. Additionally, high efficiency, low construction costs and high compatibility and flexibility of ORC systems mean that their installation on ICE exhaust systems is economically justified and simple. The article below proves the legitimacy of considering the above-mentioned solution, proposes an ORC system concept for a laboratory ICE, presents a diagram of the procedure during the design/construction of the system and presents the initial energy balance of the solution.

Study on modified poplar wood powder/polylactic acid high toughness green 3D printing composites

In order to alleviate environmental pollution and the shortage of petroleum resources, improve the utilization of renewable materials, the research of biodegradable green composite materials has become a research hotspot. In this paper, Poplar Wood powder(PWP) and Polylactic acid(PLA) were selected, adding poly lactic acid graft maleic anhydride (MPLA) and Silane coupling agent KH-550 (KH550) as a compatibilizer and coupling agent to improve interface compatibility, at the same time, poly Butylenedioate-co-terephthalate (PBAT) and poly Butylene Succinate (PBS) were added to improve the toughness of the composites. The experimental results show that, the impact strength of 20 %-KMPP/PBAT/PBS composite modified by MPLA and KH550 was 20.70 kJ/m−2. Secondly, the hydrophobic angle of the composite material is as high as 112°. It is found that the high content of PWP with small particle size (200 mesh) can make it more evenly dispersed in the composite material, and the cross section of the composite material was smooth. The modified composite was 4.24$/kg, which reduced the cost by 28.07 %. The research results have opened up a new way to develop 3D printed biomass composites with low cost, high compatibility, high toughness and good environmental adaptability, and broadened the application scope and value of the composites.

Ultrafast organic solvent nanofiltration in C[sbnd]C bonded conjugated microporous membrane-based nanochannels by space-confined polymerization

Organic solvent nanofiltration is a new membrane technology for separation of organic solvents with low energy consumption and environmental compatibility. However, commercial ultrafiltration membranes are unsuitable for organic solvents separation owing to their low retention and poor solvent resistance. CC bonded conjugated microporous polymer (CCMP) membranes consisting of all-rigid conjugated systems feature well-developed microporosity and excellent organic resistance. Herein, we report a strategy to prepare solvent-resistant CCMP@PTFE composite membrane by portioning channels in polytetrafluoroethylene (PTFE) ultrafiltration membrane by space-confined polymerization. Owing to intrinsic micropores from crosslinking of multifunctional rigid building units and the robustness of PTFE substrate, three CCMP@PTFE membranes exhibit outstanding separation performance, solvent resistance and high flexibility, which rival against the best of those reported membranes. This strategy inspires the design of OSN membranes with high performance.

Boost Up the Mechanical and Electrical Property of CNT Fibers by Governing Lyotropic Liquid Crystalline Mesophases with Aramid Polymers for Robust Lightweight Wiring Applications

Monofilament type of polyaromatic amide (PA) and carbon nanotube (CNT) composite fibers is presented. A concept of a lyotropic liquid crystal (LLC) constructed via a spontaneous self-assembly is introduced to mitigate the extremely low compatibility between PA and CNT. These approaches provide an effective co-processing route of PA and CNT simultaneously to fabricate the uniform, continuous, and reliable composite fibers through a wet-spinning. Interestingly, the addition of a small amount PA into the dope solution of CNT governs the LLC mesophase not only in a spinneret stage but also in a coagulant region. Thus, the developed PA/CNT composite fibers have the high uniaxial orientational order and the close interfacial packing compared to the pure CNT fibers. The PA/CNT composite fibers achieve the outstanding tensile strength, electrical conductivity, and electrochemical response, while maintaining a lightweight. They also exhibit the chemical, mechanical, and thermal robustness. All of these advantages can make flexible, sewable, and washable PA/CNT composite fibers ideal nanocomposite materials for use in next-generation information and energy transporting system by replacing conventional metal electrical conductors.Graphical The lyotropic liquid crystal self-assembly governed by doping the aramid polymers shows the ability to construct mechanically strong and continuous carbon nanotube-based composite fibers that can be used in the lightweight and robust electrical wiring for extreme environmental applications.

Green synthesis of iron nanoparticles for malachite green removal

Green synthesis of iron nanoparticles (Fe NPs) using plant extract is a suitable alternative for chemically synthesised Fe NPs due to their low cost, high stability, high reactivity, and environmental compatibility. The objective of the present study is to synthesise Fe NPs from ethanolic seed coat extracts of Strychnos nux vomica (SN) and Abrus precatorius (AP) and to investigate the removal efficiency for malachite green dye (MG). The synthesised AP-Fe NPs exist in crystalline and amorphous forms with particle sizes ranging between 3-32 nm, whereas SN-Fe NPs are amorphous with particle sizes ranging between 2.1-5 nm. The removal efficiency of prepared Fe NPs for MG shows that the AP-Fe NPs were more effective than SN-Fe NPs. The malachite green removal efficiency increases with increasing nanoparticle dosage and contact time. Acidic pH and low initial concentration of the dye solution were the other favourable conditions for malachite green removal. [4-(dimethylamino)phenyl]-phenylmethanone, benzoic acid and diphenylmethanone are the malachite green degradation products identified after treating with AP-Fe nanoparticles. • Fe nanoparticles were prepared using plant extracts of Strychnos nux vomica and Abrus precatorius . • AP-Fe nanoparticles show high malachite green removal efficiency compared to SN-Fe nanoparticles. • Degradation product of malachite green using AP-Fe nanoparticles were identified.

A novel and simple naphthol azo dye chemosensor as a naked eye detection tool for highly selective, sensitive and accurate determination of thiourea in tap water, juices and fruit skins

In the present study, a highly accurate and sensitive azo-dye-based colorimetric sensor based on Eriochrome Black T (EBT) was proposed to detect and determine thiourea (TU). TU is truly an important toxic and carcinogenic hazardous pollutant as approved by EPA and IARC. This chemosensor shows a distinct color change from blue to pink during interaction with TU in aqueous medium. So EBT is capable as an applied tool for naked eye detection of TU as its color change is easily observed without any means. The sensing mechanism was also investigated using UV–vis absorption and FT-IR spectra. The linear range and the detection limit of TU sensing were respectively 0.15–18.5 μmol/L and 0.02 μmol/L. In addition, the relative standard deviation (RSD) based on ten repetitions calculated for two different TU concentrations 4.4 and 9.0 μmol/L were 2.3 % and 1.8 %, respectively. Besides its useful application as a naked eye detection tool, the advantages of the developed method include simplicity, elimination of tedious separation and pre-concentration steps, executable in neutral aqueous media, low costs, high accuracy, linear response for wide range of concentrations, low detection limit, high sensitivity, compatibility, and excellent selectivity. The concentration of TU in tap water, fruit juices or fruit skin samples can be visually detected and determined easily using this method. The results showed that EBT is an ideal colorimetric chemosensor for TU, which has been reported for the first time.