Sulfide Groups Research Articles

Dibenzothiophene S, S-Dioxide-Containing Dipolar Molecules As Efficient Hole-Transport Materials for p-i-n Perovskite Solar Cells.

Organic-inorganic hybrid perovskite solar cells (OIH-PSCs) have developed rapidly in the past decade, and the commercialization of OIH-PSCs demands low-cost hole-transport materials (HTMs) with high performance and stability. The present study synthesized two organic HTMs containing dibenzothiophene S-dioxide as the acceptor unit and triphenylamine as the donor (denoted by TPAF-SO2 and TPA-SO2). In TPAF-SO2, the methoxy group and adjacent fluorine atom were introduced to decrease the highest occupied molecular orbital energy level. In TPA-SO2, the methyl sulfide group is the end group that can passivate the lead ion. TPAF-SO2 and TPA-SO2 exhibit hole-transport mobilities as high as 1.12 × 10-3 and 2.31 × 10-3 cm2 v-1 s-1, respectively, and strongly passivate Pb vacancies. Compared with TPAF-SO2, TPA-SO2 is more suitable for the growth of perovskite crystals. The perovskite grown on the latter has a lower trap density and higher carrier mobility; thus, both the nonradiative recombination and the charge-transport loss are decreased. The OIH-PSC based on TPA-SO2 as the HTM achieved a power conversion efficiency (PCE) as high as 22.08%, whereas the device based on TPAF-SO2 achieved a PCE of only 18.42%. In addition, the unencapsulated device based on TPA-SO2 can maintain 85% of the initial PCE after being stored in N2 for 1200 h, whereas the device based on TPAF-SO2 decayed rapidly to zero in 800 h under the same conditions.

Comparative study on the immune surveillance injury of blood cerebrospinal fluid barrier induced by exposure to lead acetate and nano-lead sulfide

Objective: To investigate the differences in terms of blood cerebrospinal fluid barrier immune surveillance injury by lead acetate and nano-lead sulfide exposure in order to provide basis for the study of their mechanism of nerve injury caused by exposure to lead and nano lead. Methods: In June 2015, forty-five SPF SD male rats were randomly divided into control group, lead acetate group (20 mg/kg) and nano-lead sulfide group (20 mg/kg), with 15 rats in each group. The rats were intragastric five times a week, for nine weeks. The numbers of CD4(+) T lymphocytes in blood and cerebrospinal fluid were detected by flow cytometry. The levels of interleukin-4 (IL-4) and interferon-γ (IFN-γ) in serum and cerebrospinal fluid were detected by ELISA. The expressions and distribution of intercellular cell adhesion molecule-1 (ICAM-1) and CD4(+) T lymphocytes in choroid plexus were detected by laser confocal fluorescence immunoassay. The mRNA expression levels of IL-4, IFN-γ and ICAM-1 in the choroid plexus were detected by real-time PCR. Results: Compared with the control group, the proportion of CD4(+) T lymphocytes in blood of rats in lead acetate group was increased, the proportions of CD4(+) T lymphocytes in cerebrospinal fluid of rats in lead acetate group and nano-lead sulfide group were increased, the contents of IL-4 and IFN-γ in serum of rats in lead acetate group and nano-lead sulfide group were increased, the content of IL-4 in cerebrospinal fluid of rats in lead acetate group and the contents of IL-4 and IFN-γ in cerebrospinal fluid of rats in nano-lead sulfide group were increased, the differences were statistically significant (P<0.05). The fluorescence intensity of ICAM-1 and CD4(+) T lymphocytes in choriochoroid plexus of rats in lead acetate group and nano-lead sulfide group were stronger than those in control group, and the fluorescence intensity of CD4(+) T lymphocytes of rats in nano-lead sulfide group was weaker than that in lead acetate group. Compared with the control group, the mRNA expression levels of ICAM-1, IL-4 and IFN-γ in choriochoroids plexus of rats in lead acetate group and nano-lead sulfide group were increased, and the mRNA expression levels of ICAM-1 and IL-4 in nano-lead sulfide group were higher than those in lead acetate group, while the mRNA expression level of IFN-γ in nano-lead sulfide group was lower than that in lead acetate group (P<0.05) . Conclusion: Exposure to lead and nano-lead sulfide can cause the increase of CD4(+) T lymphocytes, IL-4, IFN-γ and ICAM-1, which may be related to the damage to the immune surveillance of the blood cerebrospinal fluid barrier. And there is a difference in the injury caused by lead and nano-lead sulfide exposure.

Biodegradability of oxidized films of polyhydroxyalkanoate copolymers containing 2-hydroxy-4-methylthiobutyrate unit in seawater

Polyhydroxyalkanoate (PHA) copolymers consisting of 3-hydroxybutyrate, 2-hydroxy-4-methylthiobutyrate (2H4MTB), and 2-hydroxy-4-methylvalerate were biosynthesized by recombinant Escherichia coli using L-methionine as the 2H4MTB precursor. The 2H4MTB unit contains a sulfide group in its side chain that can be oxidized to sulfoxide and sulfone groups by oxidants, thereby increasing the hydrophilicity of the polymer. The PHAs were biosynthesized at 3.9, 9.2, and 13.9 mol% 2H4MTB, and their polymer films were oxidized with hydrogen peroxide. The surface of the oxidized film was characterized using Fourier-transform infrared spectroscopy, Raman spectroscopy, and contact angle analysis. The oxidized films with 13.9 mol% 2H4MTB showed a 30° lower water contact angle than the non-oxidized films. To assess their marine biodegradability, the PHA films were immersed for 114 days in seawater continuously pumped from two depths (24 and 397 m) in Suruga Bay, Shizuoka, Japan. The weight loss of the films immersed in deep seawater was higher than that of those immersed in surface seawater. Additionally, there was a tendency for higher degradation of the oxidized films than that of the non-oxidized films, which was also confirmed by the biochemical oxygen demand test. In the surface morphology analysis by scanning electron microscopy, irregularities were observed in the degraded films, but their morphologies differed between the oxidized and non-oxidized films. Based on these observations, the biodegradation of the PHA films in seawater is discussed.

Oxidation-Responsive Supramolecular Hydrogels Based on Glucosamine Derivatives with an Aryl Sulfide Group.

Supramolecular hydrogels can be obtained via self-assembly of small molecules in aqueous environments. In this study, we describe the development of oxidation-responsive supramolecular hydrogels comprising glucosamine derivatives with an aryl sulfide group. We demonstrate that hydrogen peroxide can induce a gel-sol transition through the oxidation of the sulfide group to the corresponding sulfoxide. Furthermore, we show that this oxidation responsiveness can be extended to photo-responsiveness with the aid of a photosensitizer.

Nanocomposite hydrogel for skin motion sensing – An antifreezing, nanoreinforced hydrogel with decorated AuNP as a multicrosslinker

In this study, we present a nanocomposite hydrogel designed for skin motion sensing. The hydrogel is based on poly(acrylamide) crosslinked with gold nanoparticles covalently bound to the polymer matrix, yielding a robust, highly elastic and conductive material. The choice of amino acid derivative – N,N’-diacryloylcystine salt (BISS) – as a crosslinker allows for the introduction of gold nanoparticles, due to the presence of sulfide groups in its structure. During the nanoparticle modification process, covalent bonds between gold and sulfur atoms are formed as the disulfide bond is cleaved. In result of this self-assembly process, a multifunctional Au–BISS crosslinker is formed, enhancing the material’s mechanical properties and introducing electrical conductivity. To confer anti-freezing properties and limit water evaporation, a binary mixture of water and glycerol was used. The resultant hydrogel exhibits high elasticity, strain sensitivity across a wide strain range and various types of deformation (elongation, bending, compression) with exceptional response time (120 ms) and recovery time (90 ms). The material’s cold-resistance, resilience, and conductivity make it well-suited for real-time monitoring of joint movements and speech recognition, with potential applications in electronic skin and healthcare monitoring devices.

Rh(III)-Catalyzed Diastereo- and Enantioselective Regiodivergent (Hetero)Arylamidation of (Homo)Allylic Sulfides.

A rhodium-catalyzed 3-component conjunctive diastereo- and regioselective arylamidation of (homo)allylic sulfides, organon boronic acids, and dioxazolones is reported. These reactions deliver the 1,2-insertion and 2,1-insertion arylamidation products, respectively, for allylic sulfides and homoallylic sulfides. The enantioselective arylamidation of terminal and internal allylic sulfides is achieved, furnishing various 1,3-N,S compounds featuring one or two contiguous stereocenters in high yields and with high diastereo- and enantioselectivities. Mechanistic studies suggest a change in the turnover-limiting and selectivity-determining steps induced by the native and easily removable sulfide group.

Phase patterning of liquid crystal elastomers by laser-induced dynamic crosslinking.

Liquid crystal elastomers hold promise in various fields due to their reversible transition of mechanical and optical properties across distinct phases. However, the lack of local phase patterning techniques and irreversible phase programming has hindered their broad implementation. Here we introduce laser-induced dynamic crosslinking, which leverages the precision and control offered by laser technology to achieve high-resolution multilevel patterning and transmittance modulation. Incorporation of allyl sulfide groups enables adaptive liquid crystal elastomers that can be reconfigured into desired phases or complex patterns. Laser-induced dynamic crosslinking is compatible with existing processing methods and allows the generation of thermo- and strain-responsive patterns that include isotropic, polydomain and monodomain phases within a single liquid crystal elastomer film. We show temporary information encryption at body temperature, expanding the functionality of liquid crystal elastomer devices in wearable applications.

The effects of high‐intensity ultrasonic treatment on emulsification, rheological properties, and flow behavior of liquid egg yolk

AbstractHigh‐intensity ultrasonic (HIU) treatment has been used to improve and modify the functional properties of food. HIU potentially inactivates microorganisms in food and modifies the physicochemical properties via the cavitation effect. This study evaluated the combination of different HIU power intensities, temperatures, and times for their effects on diluted liquid egg yolks’ physicochemical properties and rheological and flow behavior. The results showed that Salmonella enteritidis and Escherichia coli in the diluted liquid egg yolks were significantly destroyed as HIU power was increased, and complete destroyed conditions were achieved at 210 W, 60°C for 6 or 9 min. Moreover, the emulsifying activity index of the diluted liquid egg yolks increased significantly at 45 and 60°C under the 75 W HIU treatment, whereas the maximum emulsifying stability index was obtained at 30°C, 210 W for 9 min. Yolk viscosity was positively correlated with HIU power intensity and temperature; the same trend was observed for flow behavior and shear stress. The fluid dynamics of the storage modulus (G′) for the 150 and 210 W HIU treatments increased significantly following the increase in temperature to 45 and 60°C, and G′ &gt; loss modulus (G″). However, free hydrogen sulfide group content also increased significantly after the HIU treatment. Thus, this study revealed that the HIU treatment effectively destroyed the bacteria population in the diluted liquid egg yolk while maintaining or improving the emulsification properties. Moreover, the diluted liquid egg yolk flow parameters apply to egg yolk product manufacturing processes.

Pyrite-assisted degradation of methoxychlor by laccase immobilized on Fe3S4/earthworm-like mesoporous SiO2.

Laccase immobilized and cross-linked on Fe3S4/earthworm-like mesoporous SiO2 (Fe3S4/EW-mSiO2) was used to degrade methoxychlor (MXC) in aqueous environments. The effects of various parameters on the degradation of MXC were determined using free and immobilized laccase. Immobilization improved the thermal stability and reuse of laccase significantly. Under the conditions of pH 4.5, temperature 40 °C, and reaction time 8 h, the degradation rate of MXC by immobilized laccase reached a maximum value of 40.99% and remained at 1/3 of the original after six cycles. The excellent degradation performance of Fe3S4/EW-mSiO2 was attributable to the pyrite (FeS2) impurity in Fe3S4, which could act as an electron donor in reductive dehalogenation. Sulfide groups and Fe2+ reduced the activation energy of the system resulting in pyrite-assisted degradation of MXC. The degradation mechanism of MXC in aqueous environments by laccase immobilized on Fe3S4/EW-mSiO2 was determined via mass spectroscopy of the degradation products. This study is a new attempt to use pyrite to support immobilized laccase degradation.

Incorporating pH into DFT-D+U and microflotation recovery studies on heterocyclic collector-pyrite interactions

This study adopted both computational and experimental approaches to design by modification of 2-mercaptobenzothiazole (MBT), 2-mercaptobenzoxazole (MBO) and 2-mercaptobenzimidazole (MBI) heterocyclic collectors by introducing a carbon sulphide (–CS2) group and forming 2-trithiocarbonatebenzothiazole (TTCBT), 2-trithiocarbonatebenzoxazole (TTCBO) and 2-trithiocarbonatebenzomidazole (TTCBI) derivatives collectors. The adsorption behaviour of the heterocyclic collectors (and derivatives) on pyrite and subsequent hydrophobicity at different pH conditions were characterised using molecular modelling and microflotation approaches, respectively. The computational adsorptions were performed on dry and hydrated surfaces in their neutral thiolate and thione (acidic) form on the pyrite (100) surface. It was found that under dry and neutral conditions the TTCBONa and TTCBTNa were more exothermic, while under dry and acidic conditions the TTCBIH was more exothermic followed by MBIH and MBTH. Under hydrated and neutral conditions MBONa was predicted as the most exothermic, while for hydrated and acidic conditions MBTH, TTCBTH and TTCBIH were more exothermic. It was found that under acidic conditions, the heterocyclic collectors were more exothermic than for neutral condition on the hydrated surface. The microflotation at pH = 8 showed that MBO achieved higher recoveries, while at pH = 6 MBT, TTCBT and TTCBI achieved higher recoveries that could reach 90 %. The derivatives under acidic conditions were found to have good recovery performance, which showed that the introduction of a –CS2 group on the exocyclic sulphur atom improved the affinity and therefore hydrophobicity of the mercapto-heterocyclic collectors on the pyrite surface, and thus these derivatives can enhance the flotation of pyrite minerals. In addition, the computational predictions complimented by experimental recoveries are essential to a meaningful development of modelling as a tool in mineral processing reagent design.

ГЕТЕРОЦИКЛИЧЕСКИЕ ТИОПРОИЗВОДНЫЕ КАМФЕНА С ФРАГМЕНТОМ ФЕНИЛТЕТРАЗОЛА

It is known that the tetrazole ring is an important pharmacophore fragment included in the structure of drugs with more than 20 types of biological activity. In order to obtain new biologically active thioterpenoids with heterocyclic fragments, we set the task of combining the natural terpene skeleton and the nitrogen-containing heterocyclic function through the biogenic sulfur atom. We have used thiylation and sulfenylchlorination of (+)-camphene and its derivatives, which are difficult to obtain synthetically (cyclopropene and allene), with 1-phenyltetrazole-5-thiol and 1-phenyltetrazole-5-sulfenyl chloride. Studying the structure of hetarene sulfide obtained by the reaction of camphene with 1-phenyltetrazole-5-thiol in the presence of a Lewis acid (boron trifluoride etherate), allowed us to conclude that during the reaction a Wagner-Meerwein rearrangement occurs. The rearrangement leads to isomerization of the initial camphane structure with the formation of a terpene sulfide of bornane structure with an exo-position of the sulfide group relative to the bicyclic skeleton of the molecule. In non-catalytic sulfenylchlorination reactions isomerization of the camphene skeleton is not observed. 2,2-Dimethylnorbornane-3-spirocyclopropene forms the product of the “normal” addition of 1-phenyltetrazole-5-sulphenyl chloride to the double bond of cyclopropene. A mixture of two regioisomers with a trans-position of the sulfide group and a chlorine atom is observed. In this case, the chlorine atom is located on the endo side of the cyclopropane ring relative to the gem-dimethyl group, while the sulfide group is on the exo side. Sulfenylchlorination of 2,2-dimethyl-3-ethenylidenenorbornane occurs regio- and stereospecifically at a sterically less hindered double bond, with the sulfide group located at the C-10 atom and the chlorine atom at the C-11 atom.

Facile synthesis of multifunctional magnetic porous organic polymers with high catalytic performance and dye adsorption capacity

Multifunctional magnetic porous organic polymers (MOPs) rich in sulfide and free phenolic hydroxyl groups were synthesized. The MOPs exhibit a large surface area and can interact strongly with metal ions and cationic dyes, including methylene blue.

Metal-Free Synthesis of 9-Sulfenylphenanthrenes via HNO3/HCl-Promoted Annulation of 2-Alkynylbiaryls with Disulfides

AbstractA metal-free thiolative annulation of 2-alkynylbiaryls with disulfides has been developed. This mild and efficient approach was promoted by inexpensive HNO3/HCl and afforded a range of corresponding 9-sulfenylphenanthrenes in good to excellent yields with a broad substrate scope and high functional group tolerance. Both sulfide groups of the disulfide reagent were used in the reaction.

Effect of sulfide on the physiological energetics of Mercenaria mercenaria

Marine sulfide is mainly produced by the reduction of sulfate. Eutrophication and anoxic conditions caused by tidal fluctuations have accelerated the production of sulfide and widened its distribution. Sulfide has toxic effects on aquatic animals, and it has important effects on physiological activities such as feeding and respiration in buried bivalves. The aim of this study was to estimate the impact of sulfide on the energy budget of the intertidal bivalve Mercenaria mercenaria. Acute toxicity experiments were first conducted on small (SS), medium (MS), and large (LS) size clams, and then clearance rate (CR), absorption efficiency (AE), respiration rate (RR), and ammonia excretion rate (ER) were measured at 24, 48, 72, and 96 h using 0 (control group), safe concentration (low sulfide group), and 96 h half-lethal concentration (high sulfide group) as sulfide concentration gradients, and scope for growth (SFG) was calculated. The results indicated that sulfide reduced the CR, AE, RR, and ER of M. mercenaria, and these indicators were lower in the high sulfide group than in the low sulfide group. The sulfide concentration and exposure time had significant effects on CR, AE, RR, and SFG. The CR of the SS low sulfide group reached its maximum value at 48 h, and the CR of the LS low sulfide and high sulfide groups reached their maximum values at 96 h and 48 h, respectively. SFG experienced a significant decrease with the extension of time, and for both MS and LS, the SFG of sulfide-treated groups was negative at all times, with the exception of 24 h. These results suggest that M. mercenaria exhibits metabolic inhibition and metabolic compensation in response to sulfide exposure. This study provides important insights for comprehending the physiological response of buried bivalves in sulfide environments and provides a scientific fundation for implementing corresponding culture measures.

Effect of various aryl substitutions on the interfacial interaction energy of graphene/conductive polymer nanocomposites

Studying intermolecular interactions in polymer nanocomposites is highly effective in achieving high-efficiency nanocomposites. To investigate the polymer nanocomposites including conductive polymers, namely poly (3-phenylhydrazone thiophene) (PPHT), poly (3-(4-n-octyl)-phenylthiophene) (POPT), and functionalized graphene nanosheet (FGN), reactive molecular dynamics (RMD) simulation were employed. The FGN structures were a result of the arylation of graphene nanosheets containing different substitutions including sulfide, amine, di-amine, and thiol functional groups. According to interaction energies at polymers / arylated graphene nanosheet, the most interaction energies resulted in nanocomposites of PPHT/graphene-thiophenyl amine (G-PATP) and POPT/graphene-p-Phenylenediamine (G-PPD). Due to the polarity of PPHT, the formation of hydrogen bonding (H-bonding) was expected at specific sites, which were confirmed based on H-bonding interaction criteria. In reality, the criteria required for detecting H-bonding through RDF and the relevant angle measurement have been established. On the other hand, due to the acidic-sensitive hydrazone bond in PPHT, it was expected that the increasing trend in interaction energy of nanocomposites of PPHT could be solely justified based on the acidity of the functional groups employed. However, based on the obtained results, other factors such as the topological polar surface area (TPSA) and the formation of unconventional H-bonding, in addition to the acidity of functional groups, have been considered as influential factors in the changing of interaction energy. Also, the dynamic behavior of polymers was examined by plotting the radius of the gyration (Rg) parameter via time and functional groups. Finally, the temperature effect on interaction energy was determined, too.

Ultra-Sensitive Determination of Cadmium in Food and Water by Flame-AAS after a New Polyvinyl Benzyl Xanthate as an Adsorbent Based Vortex Assisted Dispersive Solid-Phase Microextraction: Multivariate Optimization.

Background: Cadmium (Cd) is a very toxic and carcinogenic heavy metal even at low levels and it is naturally present in water as well as in food. Methods: A new polyvinyl benzyl xanthate (PvbXa) was synthesized and used as a new adsorbent in this work. It contains pendant sulfide groups on the main polystyryl chain. Using this new adsorbent, PvbXa, a vortex-assisted dispersive solid-phase microextraction (VA-dSPµE) procedure was developed for the determination of cadmium from food and water samples via flame atomic absorption spectrophotometry (FAAS). Synthesized PvbXa was characterized by 1H Nuclear magnetic resonance (NMR) Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Photoelectron Spectroscopy (XPS). The different parameters of pH, sample volume, mixing type and time, sorbent amount, and eluent time were optimized using standard analytical methods. Results: The optimized method for assessment of Cd in food and water samples shows good reliability. The optimum conditions were found to be a 0.20-150 µg L-1 linear range, 0.06 µg L-1 LOD, 0.20 µg L-1 LOQ, 4.3 RSD %, and a preconcentration factor of 160. Conclusions: The statistically experimental variables were utilized using a central composite design (CCD). The present method is a low-cost, simple, sensitive, and very effective tool for the recovery of Cd.

Facile preparation of triazole-functionalized poly(arylene perfluorophenyl) high temperature proton exchange membranes via para-fluoro-thiol click reaction with high radical resistance

For the development of high temperature proton exchange membranes (HT-PEMs), several challenges still need to be overcome, including high proton conductivity, low swelling, and superior oxidation stability. In this work, we reported a facile and efficient strategy to developing a novel class of phosphoric acid (PA) doped HT-PEMs based on triazole-functionalized poly(arylene perfluorophenyl)s. Arylene ether-free all-carbon backbone aromatic polymers were synthesized via a superacid-catalyzed reaction, and the grafting of sulfide-linked triazole groups was completed by a quantitative and selective para-fluoro-thiol click reaction. 1H and 19F NMR spectra confirmed their chemical structures and the grafting degrees of 100%. The series of triazole-functionalized polymers exhibited high thermal decomposition temperatures (Td5% above 200 °C) and tensile strengths. At 180 °C, the obtained HT-PEMs showed a proton conductivity up to 109.8 mS cm-1 while maintaining volume swellings below 152% and thickness swellings below 52%. In a single fuel cell at 160 °C, the high proton conductivity of the membrane resulted in a peak power density of 760 mW cm-2 without external humidification and backpressure. Owing to the existence of sulfide group in the side chain, HT-PEMs remained intact and retained high residual weight after 72 hours treatment with Fenton's reagent, enabling them to have good durability in fuel cell. The results demonstrate that the prepared HT-PEMs with high radical resistance and superior performance have promising potential for application in high temperature proton exchange membrane fuel cells.

A Readily Available Red‐Emitting Methylthio‐Substituted Salicylaldehyde Azine with AIE Feature for Ratiometric Detection of HClO

AbstractDeveloping a simple, selective, and rapid reliable method to monitor hypochlorous acid (HClO) in vivo is very meaningful due to its important physiological and pathological functions. In this research, a novel AIE based fluorescent probe for ratiometric detection of HClO was fabricated by a simple one‐step synthesis, in which the methyl sulfide group and salicylaldehyde azine serve as the recognition unit and fluorophore, respectively. This probe was visible‐light‐excitable, and showed a palpable aggregation‐induced emission into the red region with high stability to Cu2+ and pH. Oxidation of the methyl sulfide group can be achieved rapidly and specifically by HClO in physiological condition, which enables it to display a rapid, ratiometric fluorescent response to HClO with high selectivity over other biologically pertinent species. By exploiting the probe‐based tool, we successfully validated its practical utility in selectively recognizing HClO in living cells via ratiometric fluorescence signals, thereby providing a potential method for investigating the relevant functions of HClO in biosystems.

MoS42- exchanged NO3- in poly-phenylglycine spherical particles for efficient removal of Pb2+ ions

Designing fast, eco-friendly, and effective adsorbent capable to eradicate heavy metal ions from complex environmental area is crucial so far. In this regard, MoS4 doped poly-N-phenylglycine "MoS4-PPG" composites have been prepared herein through radical polymerization. Such a composites have been obtained after an initial synthesizes of NO3 doped poly-N-phenylglycine (NO3-PPG) using Fe3+ as oxidant followed by ion exchange method. Scanning electron microscopy (SEM) illustrates the high homogeneity of the mixture composed of spherical MoS4-PPG particles. The stoichiometry of MoS4 has been determined via energy dispersive x-ray analysis (EDX) and X-ray photoelectron spectroscopy (XPS). Fourier transform infrared (FTIR) spectroscopy and Raman analysis also confirm the substitution of NO3- with MoS42- ions. A significant adsorption of MoS4-PPG for Pb2+ in aqueous solution with qexp of about 59.53 mg/g is observed owing to the anchored sulfide groups. The experimental data have been properly fitted through Langmuir model when the removed monolayer of Pb2+ ions occupy the entire adsorbent surface.

Toxicity assessment of heavy metal (Pb) and its bioremediation by potential bacterial isolates.

Lead (Pb) is a non-essential metal with high toxicity, is persistent, is not biodegradable, and has no known biological function. It is responsible for severe health and environmental issues that need appropriate remediation. Therefore, microbes have thrived in a lead-contaminated environment without exhibiting any negative impacts. The present study aimed to examine the toxic effects of lead on animals and the isolation, identification, and characterization of lead-resistant bacterial strains and their biodegradation potential. After oral administration of lead for 4weeks, mice showed an elevated level of leukocytes and a decrease in TEC, Hb, PCV, MCV, MCH, and MCHC levels. However, a decline in body weight and inflammation and oxidative stress was observed in liver tissues. To remediate toxic heavy metal, lead-resistant bacterial strains were isolated, among which Enterobacter exhibited maximum degradation potential at high lead concentrations. It was identified by molecular basis and after 16S rRNA sequencing, and 99% resemblance was observed with Enterobacter cloacae. FT-IR analysis of the bacteria illustrated the presence of functional groups, including hydroxyl, carboxyl group, sulfide, and amino groups, on the bacterial cell surface involved in the adsorption of lead. Moreover, electron microscopy (SEM) revealed the morphological and physiochemical changes in the bacterial cell after biosorption, indicating the interaction of Cu ions with functional groups. To summarize, the findings show the highly toxic effects of lead on animals and humans and its effective biodegradation by the bacterial strains in the lead-contaminated environment. This biological strategy can be an ideal alternative to remediate heavy metals from contaminated sites to clean up the environment.