Industrial thiocyanate (SCN−) waste streams from gold mining and coal coking have caused serious environmental pollution worldwide. Phytoremediation is an efficient technology in treating hazardous ...wastes from the environment. However, the phytoremediation efficiency of thiocyanate is very low due to the fact that plants lack thiocyanate degradation enzymes. In this study, the thiocyanate hydrolase module was assembled correctly in rice seedlings and showed thiocyanate hydrolase activity. Rice seedlings engineered to express thiocyanate degrading activity were able to completely remove thiocyanate from coking wastewater. Our findings suggest that transforming the thiocyanate hydrolase module into plants is an efficient strategy for rapid phytoremediation of thiocyanate in the environment. Moreover, the rice seedlings expressing apoplastic or cytoplasmic targeted thiocyanate hydrolase module were constructed to compare the phytoremediation efficiency of secretory/intracellular recombinant thiocyanate hydrolase. The most obvious finding from this study is that the apoplastic expression system is more efficient than the cytoplasm expression system in the phytoremediation of thiocyanate. At last, this research also shows that the secreted thiocyanate hydrolase from engineered rice plants does not influence rhizosphere bacterial community composition.
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•Two thiocyanate hydrolase modules are constructed and expressed in plants.•The thiocyanate hydrolase modules were assembled correctly in the rice plant and showed SCNase activity.•The plants expressing the thiocyanate hydrolase module can degrade thiocyanate completely.•The plants expressing thiocyanate hydrolase module enhances phytoremediation of thiocyanate.•Apoplast-targeted expressing plants showed high-level phytoremediation than the cytoplasm expressing plants
Summary
Secondary metabolism is characterized by an impressive structural diversity. Here, we have addressed the mechanisms underlying structural diversification upon damage‐induced activation of ...glucosinolates, a group of thioglucosides found in the Brassicales. The classical pathway of glucosinolate activation involves myrosinase‐catalyzed hydrolysis and rearrangement of the aglucone to an isothiocyanate. Plants of the Brassicaceae possess specifier proteins, i.e. non‐heme iron proteins that promote the formation of alternative products by interfering with this reaction through unknown mechanisms. We have used structural information available for the thiocyanate‐forming protein from Thlaspi arvense (TaTFP), to test the impact of loops protruding at one side of its β‐propeller structure on product formation using the allylglucosinolate aglucone as substrate. In silico loop structure sampling and semiempirical quantum mechanical calculations identified a 3L2 loop conformation that enabled the Fe2+ cofactor to interact with the double bond of the allyl side chain. Only this arrangement enabled the formation of allylthiocyanate, a specific product of TaTFP. Simulation of 3,4‐epithiobutane nitrile formation, the second known product of TaTFP, required an alternative substrate docking arrangement in which Fe2+ interacts with the aglucone thiolate. In agreement with these results, substitution of 3L2 amino acid residues involved in the conformational change as well as exchange of critical amino acid residues of neighboring loops affected the allylthiocyanate versus epithionitrile proportion obtained upon myrosinase‐catalyzed allylglucosinolate hydrolysis in the presence of TaTFP in vitro. Based on these insights, we propose that specifier proteins are catalysts that might be classified as Fe2+‐dependent lyases.
Significance Statement
Structural diversification upon glucosinolate breakdown is controlled by specifier proteins, a group of non‐heme iron proteins. Our study provides mechanistic insights that identify specifier proteins as Fe2+‐dependent C‐S/C‐C lyases. By contrast with the role of Fe2+ in sulfur ion during simple nitrile formation, thiocyanate and epithionitrile formation depends on Fe2+/Fe3+ as a redox partner. Thiocyanate formation by Thlaspi arvense thiocyanate‐forming protein requires a conformational change that enables an alternative substrate docking pose.
Zinc oxy-sulphide (ZnO1-xSx) has proven to be the most promising material for electron transport layer (ETL) as a replacement of CdS in thin film and perovskite solar cells due to its ability to tune ...the bandgap energy (2.7–3.8 eV). FASnI3 (CH4N2SnI3) based perovskite solar cells are found to be more efficient and stable than their MASnI3 counterparts because of its wider bandgap (1.41 eV) and better temperature stability. In this paper, FASnI3 based perovskite solar cell employing zinc oxy-sulphide (Zn (O0.3, S0.7)) as ETL and copper thiocyanate (CuSCN) as HTL is presented. The proposed structure FTO/Zn(O0.3, S0.7)/FASnI3/CuSCN/Au has been simulated using SCAPS-1D software. The parameters from various experimental and theoretical reported works were used to simulate the proposed solar cell and it resulted in 14.46% of power conversion efficiency (PCE). In order to investigate the impact of active layer on the performance of the proposed device, the parameters of active layer like thickness and defect density have been varied. Furthermore, parameters such as electron affinity, doping density and thickness of ETL and HTL respectively have also been varied to examine their influence on the output device parameters and optimized results deduced accordingly. Finally, the device simulation with the optimized parameters has resulted in improved output parameters with VOC of 1.0859 V, JSC of 28.12 mAcm−2, FF of 84.96% and PCE of 25.94%, thus, paving the way for novel perovskite solar cells employing tin which are environmentally safe being lead free and have efficiency comparable tothe lead based counterparts.
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•FASnI3 based lead free PSC with Zn (O0.3, S0.7) as an ETL in n-i-p configuration is presented.•The effect of Zn (O0.3, S0.7) ETL on PSC performance by SCAPS-1D simulation is investigated.•Variation in electron affinity, CBO, doping density and thickness of Zn (O0.3, S0.7) on the performance of PSC is analysed.•Conclusive PSC Parameters thus obtained are: VOC-1.0859 V, JSC-28.12 mAcm−2, FF-84.96% and PCE-25.94%.
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•Novel metallic complexes of Cobalt Co(II) and Nickel Ni(II) complexes of 2-aminothiazole (ATZ) and thiocyanate ligands have been developed.•Antibacterial capabilities of ligands and ...their Co(II) and Ni(II) compounds were studied.•Complexes exhibit potential against the fungus than bacteria.
Using the microwave irradiation approach, novel metallic complexes of Cobalt Co(II) and Nickel Ni(II) complexes of 2-aminothiazole (ATZ) and thiocyanate ligands IUPAC Name: Di(2-aminothiazole) thiocyanato cobalt(II), Di(2-aminothiazole) thiocyanato nickel(II) were created. The molecular formulas and the geometry of the complexes have been deduced by elemental analysis, molar conductance, magnetic moment, UV–visible, FT-IR, thermogravimetric analysis, cyclic voltammetry, and powder-XRD techniques. Molar conductance values indicate that the complexes are non-electrolyte (1:0) type. The complexes have octahedral structure is revealed by the magnetic moment and UV–visible spectra. The FT-IR spectra reveal that the 2-aminothiazole and thiocyanate ions are coordinated to the metal ion in a monodentate manner. The antibacterial capabilities of ligands and their Co(II) and Ni(II) compounds were studied against a restricted set of microorganisms utilizing the agar-well diffusion method and varying concentrations.When compared to free 2-aminothiazole ligand, the complexes exhibit possible activity against the fungus than bacteria. By assessing how well the complexes and ligands interact with the stable free radical DPPH, their ability to scavenge free radicals has been established. Comparing the complexes to the free ligand, the complexes exhibit greater antioxidant activity due to the fact that metal complexes are widely recognized for their capacity to accelerate medication action and boost therapeutic agent potency when they coordinate with a metal ion. The primary goal of this research is to develop multimodal medicinal drugs, which include studying the roles of 2-aminothiazole and its transition metal complexes.
Besides widely used surface passivation, engineering the film crystallization is an important and more fundamental route to improve the performance of all‐inorganic perovskite solar cells. Herein, we ...have developed a urea‐ammonium thiocyanate (UAT) molten salt modification strategy to fully release and exploit coordination activities of SCN− to deposit high‐quality CsPbI3 film for efficient and stable all‐inorganic solar cells. The UAT is derived by the hydrogen bond interactions between urea and NH4+ from NH4SCN. With the UAT, the crystal quality of the CsPbI3 film has been significantly improved and a long single‐exponential charge recombination lifetime of over 30 ns has been achieved. With these benefits, the cell efficiency has been promoted to over 20 % (steady‐state efficiency of 19.2 %) with excellent operational stability over 1000 h. These results demonstrate a promising development route of the CsPbI3 related photoelectric devices.
A new urea‐ammonium thiocyanate (UAT) molten salt was introduced as the additive in all‐inorganic cesium lead triiodide solar cell, as a modification strategy to fully release and exploit coordination activities of SCN− to deposit high‐quality CsPbI3 film. Thus, the UAT‐based devices can provide an encouraging PCE up to 20.08 % with excellent operational stability of over 1000 h.
The wide bandgap and highly transparent inorganic compound copper(I) thiocyanate (CuSCN) is used for the first time to fabricate p‐type thin‐film transistors processed from solution at room ...temperature. By combining CuSCN with the high‐k relaxor ferroelectric polymeric dielectric P(VDF‐TrFE‐CFE), we demonstrate low‐voltage transistors with hole mobilities on the order of 0.1 cm2 V−1 s−1. By integrating two CuSCN transistors, unipolar logic NOT gates are also demonstrated.
A new solid-contact potentiometric ion-selective electrode for the determination of SCN
(SCN-ISE) has been described. Synthesized phosphonium derivative of calix4arene was used as a charged ...ionophore. The research included selection of the ion-selective membrane composition, determination of the ISEs metrological parameters and SCN-ISE application for thiocyanate determination in human saliva. Preparation of the ISEs included selection of a plasticizer for the ion-selective membrane composition and type of the electrode material. The study was carried out using ISE with liquid internal electrolyte (LE-ISE) and solid-contact electrodes made of glassy carbon (GC-ISE) and gold rods (Au-ISE). The best parameters were found for GC sensors for which the ion-selective membrane contained chloroparaffin as a plasticizer (S = 59.9 mV/dec, LOD = 1.6 ´ 10
M). The study of potentiometric selectivity coefficients has shown that the thiocyanate-selective sensor could be applied in biomedical research for determination of SCN
concentration in human saliva. The accuracy of the SCN
determination was verified by testing 59 samples of volunteers' saliva by potentiometric sensors and UV-Vis spectrophotometry as a reference technique. Moreover, SCN
concentrations in the smokers' and non-smokers' saliva were compared. In order to investigate the influence of various factors (sex, health status, taken medications) on the thiocyanate level in the saliva, more extensive studies on a group of 100 volunteers were carried out. Additionally, for a group of 18 volunteers, individual profiles of SCN
concentration in saliva measured on a daily basis for over a month were collected.
Metal halide perovskite quantum dots (Pe‐QDs) are of great interest in new‐generation photovoltaics (PVs). However, it remains challenging in the construction of conductive and intact Pe‐QD films to ...maximize their functionality. Herein, a ligand‐assisted surface matrix strategy to engineer the surface and packing states of Pe‐QD solids is demonstrated by a mild thermal annealing treatment after ligand exchange processing (referred to as “LE‐TA”) triggered by guanidinium thiocyanate. The “LE‐TA” method induces the formation of surface matrix on CsPbI3 QDs, which is dominated by the cationic guanidinium (GA+) rather than the SCN−, maintaining the intact cubic structure and facilitating interparticle electrical interaction of QD solids. Consequently, the GA‐matrix‐confined CsPbI3 QDs exhibit remarkably enhanced charge mobility and carrier diffusion length compared to control ones, leading to a champion power conversion efficiency of 15.21% when assembled in PVs, which is one of the highest among all Pe‐QD solar cells. Additionally, the “LE‐TA” method shows similar effects when applied to other Pe‐QD PV systems like CsPbBr3 and FAPbI3 (FA = formamidinium), indicating its versatility in regulating the surfaces of various Pe‐QDs. This work may afford new guidelines to construct electrically conductive and structurally intact Pe‐QD solids for efficient optoelectronic devices.
A ligand‐assisted matrix to regulate surface and packing states of perovskite quantum dots (QDs) is demonstrated, which involves a ligand exchange and a mild thermal annealing process that are triggered by guanidinium thiocyanate. Consequently, the CsPbI3 QD solar cells (QDSCs) deliver a champion power conversion efficiency of 15.21%, which is the highest report among all CsPbI3 QDSCs.
The electrophilic thiocyanation of aromatic and heteroaromatic compounds such as oxindoles, indoles, isatins, indolines, quinolines, and pyrroles and also N-activeted arenes such as anilines, ...N,N-dialkylamines, and arylamines with thiocyanation agent/oxidant in the presence of acidic catalyst are represents an essential direct procedure to the synthesis of aryl and heteroaryl thiocyanates derivatives. Various thiocyanation agents such as NH4SCN, KSCN and some catalysts especially ILs with thiocyanation agent are an important reagent for the production of such class of thiocyanate intermediates. In the decade past, the considerable advances have been made for the direct thiocyanation of aromatic, heteroaromatic and N-activeted arenes compounds with high selectivity and yield. In this review, we have classified a variety of procedures the last nine years based on various catalysts for the preparation of aryl and heteroaryl thiocyanates derivatives since 2012 until now.
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An eco-friendly and practical method for the ultrasonic multicomponent synthesis of diverse (Z)-β-iodo vinylthiocyanates from cheap and commercially available alkynes, molecular iodine, and KSCN ...through an intermolecular H-bonding assistance strategy was developed.
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