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Montmorillonite-based porous adsorbent prepared by gel casting method was used to adsorb Cr(III)-organic complexes in tanning wastewater,together with the initial concentration of 10 mg L−1. The as-porous adsorbent exhibited an excellent performance of separation. Meanwhile, its structural and morphology were characterized by TG, BET, XRD, SEM, EDS and XPS, showing that the porous adsorbent was complete hollow ball structure. And the adsorption results showed that the adsorption amount of porous adsorbent rapidly declined from 9.58 to 5.28 mg L−1, and only Cr(III) was adsorbed, when the molar ratio of Cr(III) and citrate was more than 1:5. Increased of pH was beneficial to adsorb Cr(III)-citrate in range from 2.46 to 7.12. Furthermore, the best removal efficiency of Cr(III)-organic complex was up to 97% and still above 84% after five cycles with porous adsorbent. Finally, the mechanism on adsorbing Cr(III) with porous adsorbent is also provided. Therefore, a kind of porous adsorbent which was easily separated, was prepared to deeply treat tanning wastewater containing Cr(III)-organic complex, and solve the problem of difficult recycle.

Oxidation of the iron(II) precursor [(L 1 )Fe II Cl 2 ] with soluble iodosylbenzene s PhIO, where L 1 is a tetradentate bispidine, leads to the extremely reactive ferryl oxidant [(L 1 )(Cl)Fe IV =O] + with a cis disposition of the chlorido and oxido coligands as observed in nonheme halogenase enzymes. Experimental data indicate that, with cyclohexane as substrate, there is selective formation of chlorocyclohexane, where the halogenation is initiated by C-H abstraction and the result of a rebound of the ensuing radical to an iron-bound Cl - . The time-resolved formation of the halogenation product indicates that this primarily results from s PhIO oxidation of an initially formed oxido-bridged diiron(III) resting state. The high yield of up to over 70% (stoichiometric reaction) as well as the differing reactivities of free Fe 2+ and Fe 3+ in comparison with [(L 1 )Fe II Cl 2 ] indicate a high complex stability of the bispidine-iron complexes. A DFT analysis shows that, due to a large driving force and small triplet-quintet gap, in comparison to other small molecule halogenase models [(L 1 )(Cl)Fe IV =O] + is the most reactive, that the Fe III / radical rebound intermediate has a relatively long lifetime, supported by experimentally observed cage escape, and that this intermediate has, as observed experimentally, a lower energy barrier to the halogenation than the hydroxylation product, and this is shown to primarily be due to steric effects.

Zirconium dioxide loaded montmorillonite (ZrO 2 -MMT) composites have been prepared using an ion-exchange process at room temperature followed by a thermal treatment. The as-prepared composites are used to adsorb Cr 3+ ions in the tanning wastewater with a lower initial Cr 3+ concentration, reducing residual Cr 3+ concentration to less than 1 mg L −1 . XRD, TEM, SEM-EDS and XPS analyses are made to explore the structure and morphology of the composites. ZrO 2 is found to load on the interlayer and surface of MMT. The adsorption process is appropriately described by the pseudo-second-order kinetic equation and Langmuir equation. The ZrO 2 -MMT composites exhibit a better adsorption capacity than adsorption materials reported in the literature, and the maximum adsorption capacity for the initial Cr 3+ concentration of 10, 20, 30 mg L −1 is as large as 142.86, 158.73 and 172.41 mg g −1 , respectively. The removal efficiency of ZrO 2 -MMT for Cr 3+ remains above 92% after six cycles.

A novel PTH-derived peptide, PTHdP, including a repetitive aspartic acid sequence at the C-terminal and phosphorylated serine at the N-terminal has been previously designed. To evaluate its potential as a bone growth factor for bone tissue engineering, true bone ceramics incorporated with nanohydroxyapatite coating and chitosan (CH/TBC) was developed as a desired three-dimensional porous delivery carrier in this study. In vitro results showed that PTHdP could be loaded with high-efficiency and subsequently released in a controlled and sustained manner from CH/TBC. Bioactivity of released PTHdP was retained and able to exert a significant effect on promoting or inhibiting osteogenesis actions when exposed intermittently or continuously, respectively, for MC3T3-E1 cell culture. As evaluated in a critical-size rabbit radial defect model by radiographic and histological examination, the combination of CH/TBC scaffolds with PTHdP exhibited a remarkably stronger capacity to stimulate new bone formation than control and pure CH/TBC groups. These results indicated the novel PTHdP peptide achieved high affinity to bone mineral without interference in bioactivity, and local delivery of PTHdP from apatite materials could be a promising alternative for future bone tissue engineering.

In this study, based on the differences in the coordination configurations of various alkaline earth metal ions (Ca(Ⅱ) and Sr(Ⅱ)) and sodium alginate (SA), the aerogel is functionalized with controllable slit-shaped pores structure, contributing by nanosheet stacking impact of graphene oxide (GO) and montmorillonite (MMT), which is able to selectively remove plane hydrate copper ions in complex wastewater systems. Sr-G/M is endowed with denser slit-shaped pores and could achieve more efficient selective removal of Cu(Ⅱ), together with a best removal efficiency of 97.1%, proving by systematic adsorption tests. The selectivity tests show that Sr-G/M exhibits preferential adsorption for Cu(Ⅱ) with a distribution coefficient of 41.85 L g−1. Furthermore, Sr-G/M has excellent regeneration performance to be 86.4% after 8 recycles. Considering its cost-effectiveness, eco-friendliness, easy preparation and efficient selective removal performance, Sr-G/M holds great promise in selective removal of Cu(Ⅱ) from complex wastewater systems.

Breast cancer is one of the leading causes of death in cancer categories, followed by lung, colorectal, and ovarian among the female gender across the world. 10H-3,6-diazaphenothiazine (PTZ) is a thiazine derivative compound that exhibits many pharmacological activities. Herein, we proceed to investigate the pharmacological activities of PTZ toward breast cancer MCF-7 cells as a representative in vitro breast cancer cell model. The PTZ exhibited a proliferation inhibition (IC50 = 0.895 µM) toward MCF-7 cells. Further, cell cycle analysis illustrated that the S-phase checkpoint was activated to achieve proliferation inhibition. In vitro cytotoxicity test on three normal cell lines (HEK293 normal kidney cells, MCF-10A normal breast cells, and H9C2 normal heart cells) demonstrated that PTZ was more potent toward cancer cells. Increase in the levels of reactive oxygen species results in polarization of mitochondrial membrane potential (ΔΨm), together with suppression of mitochondrial thioredoxin reductase enzymatic activity suggested that PTZ induced oxidative damages toward mitochondria and contributed to improved drug efficacy toward treatment. The RT2 PCR Profiler Array (human apoptosis pathways) proved that PTZ induced cell death via mitochondria-dependent and cell death receptor-dependent pathways, through a series of modulation of caspases, and the respective morphology of apoptosis was observed. Mechanistic studies of apoptosis suggested that PTZ inhibited AKT1 pathways resulting in enhanced drug efficacy despite it preventing invasion of cancer cells. These results showed the effectiveness of PTZ in initiation of apoptosis, programmed cell death, toward highly chemoresistant MCF-7 cells, thus suggesting its potential as a chemotherapeutic drug.

Titanium dioxide/graphene (TiO2/G) was synthesized by a simple method through adding cationic surfactant to assist the stabilization of rutile TiO2 in aqueous solutions and facilitate the electrostatic assembly of binding with surface of graphene. TiO2/G materials were used for investigation of its conductivity and dispersibility. The TiO2/G was showed significantly to enhance in conductivity and dispersibility after adding cetyltrimethylammonium bromide (CTAB). The good performance may be attributed to increasing TiO2 to uniformly distribute on the surface of graphene in the presence of CTAB. The TiO2/G composite was characterized by Zeta potential, Fourier transformed infrared spectra (IR), X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Electrochemical impedance spectroscopy (EIS), respectively. The CTAB does not affect the crystalline structure of TiO2 and graphene. When CTAB is 30%wt of TiO2 and graphene is 7%wt of TiO2 that the resistivity of TiO2/G is measured as 2.4 Ω cm. The dispersion of TiO2/G can be kept for 24 h without precipitation. EIS showed that the TiO2/G with 30%wt of CTAB had the lowest electrical resistance, which tended to be consistent with the results of the measured resistivity. The results showed that the best conductivity and dispersibility of the TiO2/G composite with CTAB in this experiment.

Based on cross-linking and freeze-drying methods, a three-dimensional network graphene oxide/sodium alginate aerogel beads (GSC) is prepared to selectively adsorb Cu(Ⅱ) in aqueous solution, with a slit-shaped structure. According to the results of characterizations, it suggests that the slit-shaped structure is formed via the stacking of GO sheets, and GO participates in the cross-linking reaction between Ca and SA connecting by Ca-carboxyl and Ca-hydroxy, as well as intermolecular hydrogen bonds between GO and SA. Furthermore, batch adsorption experiments and Design of Experiment (DOE) show that GSC has excellent adsorption capacity and reusability, and pH is the main factor that affects the adsorption performance of GSC. Importantly, the slit-shaped structure of GSC can still selectively adsorb plane quadrilateral [Cu(H2O)4]2+ in the presence of interfering ions (Zn(II), Mn(II) and Cr(Ⅲ)). The fitting results of adsorption kinetics and isotherm model prove that the adsorption process is mainly multi-layer adsorption and chemical adsorption. Additionally, the mechanism is explored using the method of Density functional theory (DFT), revealing that -COOH, -O-, -OH on GO play important roles in adsorbing Cu(Ⅱ), and the order of is: -COOH>-O->-OH.

Graphene oxide-titanium dioxide/sodium alginate (GO-TiO2/SA) composite beads are successfully prepared based on blending and cross-linking process, performing as adsorbent to remove Cu(II) in aqueous solution. Meanwhile, the cross-linking mechanism are explored and the morphology of the GO-TiO2/SA composite beads are characterized via FTIR, SEM, EDS, Raman and XPS. These results reveal that the porous network is created, corresponding to form hydrogen bonds, C O Ti among TiO2, GO and SA, as well as the cross-linking between carboxyl and Ca2+. In comparison with GO/SA composite beads, GO-TiO2/SA composite beads are endowed with a more integral porous structure and a larger specific surface area, observing from the characterizations of BET and SEM, confirming that better adsorption performance is achieved. Furthermore, the adsorption experiments of Cu(II) are carried out in terms of varying the dosage of the composite beads, temperature, pH and adsorption time. And the adsorption behavior can be better described by the pseudo-second-order kinetic model and Langmuir model. Importantly, GO-TiO2/SA composite beads maintain the undamaged structure and larger pore sizes when undergoing adsorption-desorption for two cycles. Finally, the adsorption mechanism on Cu(II) with GO-TiO2/SA composite beads is also explored via FTIR, EDS and XPS.

Recovering Cr(III) from chromium-containing waste (CCW) is considered to be a friendly way to protect environment. In this paper, the recovery of Cr(III) from CCW is achieved, via alkali incineration (NaOH and Na2CO3), followed with leaching process using HCl. Firstly, it is demonstrated that there is a large amount of organic matters (oxygen-containing functional groups contained in collagen) in CCW, charactering with Infrared spectrophotometry (FT-IR), Thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). Furthermore, density functional theory (DFT) simulation method is carried out to study the inhibitory behavior of organic matters on recovery of Cr(III). Through geometric optimization, binding energy calculation and a series of electronic structure analysis, the influence of organic matters are analyzed in detail. According to the calculation results, it is clarified that the inhibition mechanism of organic matters on Cr(III) is mainly contributing by forming covalent bond and -OH exhibits greater inhibiting effect than -COOH. In this examine, the related factors are also investigated to reduce the amount of organic matters that is destroyed, including extractant species, alkali dosage, acid dosage and acid concentrations. Finally, the recovering efficiency of Cr(III) is greatly enhanced (95.83%), associated with optimized factors in the process.

In this study, GO-TiO2 composite material, with abundant oxygen-containing functional groups is prepared in way of loading TiO2 on the surface of GO, binding with C–O–Ti chemical bonds. Especially the resulted anatase-type TiO2 is originated from hydrolyzing butyl titanate in condition of mild water bath (80 ​°C), so that the oxygen-containing functional groups onto GO-TiO2 could be greatly retained to improve its performance for adsorbing Cr3+ (10–30 ​mg/L) in wastewater. A variety of characterizations, including SEM, TEM, FT-IR, XRD, XPS, Zeta and Raman are employed to demonstrate that TiO2 is uniformly dispersed on the surface of GO and the oxygen-containing functional groups onto GO have been greatly retained. Moreover, the adsorptive process of Cr3+ on GO-TiO2 corresponds to the quasi-second-order kinetic equation and Langmuir equation (maximum potential of adsorption could reach up to 149.24 ​mg/g). Furthermore, the thermodynamics studies imply that the adsorption process toward Cr3+ is spontaneous and endothermic. Importantly, density functional theory (DFT) calculations have also been performed to illustrate the order of oxygen-containing functional groups which bind with Cr3+: E0(-OH) ​> ​E0(-O-) ​> ​E0(-COOH). After five cycles, the removal efficiency is still over 85%, suggesting that the resulted adsorbent performs great potential in removing Cr3+ from wastewater.

Chromium (Cr) has become one of the main pollutants in tannery wastewater, which causes great harm to human health and environment, especially after being oxidized. Herein, the magnetic graphene oxide composite (GO/Fe3O4) is synthesized via coprecipitation method with NH3·H2O. In this way, the self-functional group of graphene oxide (GO) are greatly reserved when Fe3O4 nanoparticles grown on GO sheets, confirming by characterizations, including Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and Raman. Up to 90% Cr3+ could be adsorbed by resulted GO/Fe3O4 within 140 min, and the maximum adsorption capacity is 279.62 mg g-1. Furthermore, Cr3+ is mainly absorbed by chemical adsorption, according with quasi-second-order kinetic model and Langmuir isotherm. Most importantly, the external magnetic field can effectively recycle the adsorbents from the aqueous solution, facilitating its application in large-scale treatment of tannery wastewater.

In this work, we introduced TiH 2 into the 17MgH 2 -12Al composite by ball milling for improving the dehydrogenation performance of the reactive system. According to the measurements of non-isothermal dehydrogenation, the onset temperature of hydrogen release from 17MgH 2 -12Al-TiH 2 was reduced by 50 °C from that of 17MgH 2 -12Al. The investigations by Kissinger's method showed that the activation energy of hydrogen desorption of 17MgH 2 -12Al-TiH 2 (107 kJ mol −1 ) is much lower than 17MgH 2 -12Al (168 kJ mol −1 ), leading to enhanced dehydrogenation kinetics due to the TiH 2 additive. X-ray diffraction (XRD) analysis suggests that TiH 2 catalyzed the reaction between MgH 2 with Al of the system during the dehydrogenation below 280 °C. At temperatures between 280 °C to 400 °C, however, TiH 2 will thoroughly react with produced Mg 17 Al 12 and liberate hydrogen. The overall reaction of the system may be represented by 17 MgH 2 + 12 Al + TiH 2 → 3/4 Mg 17 Al 12 + Al 3 Ti + 17/4 Mg + 18 H 2 . Its theoretical dehydrogenation capacity (4.38 wt% H 2 ) agrees well with that achieved by temperature programmed dehydrogenation (TPD) measurements, demonstrating the occurrence of such reaction(s). The dehydrogenation enthalpy of 17MgH 2 -12Al-TiH 2 (71.7 kJ mol −1 H 2 ) proceeding at lower hydrogen desorption plateau was significantly lowered from that of 17MgH 2 -12Al (81.9 kJ mol −1 H 2 ) according to the measurements of pressure-composition isotherms (PCI) and van't Hoff plots. It means that TiH 2 was involved in the end reaction proceeding in the 17MgH 2 -12Al system. We believe that TiH 2 improves the dehydrogenation kinetics of 17MgH 2 -12Al initially and tailors its thermodynamics finally.

TiH2 was introduced into the 4MgH2-NaAlH4 composite by ball milling to improve the dehydrogenation and re-dehydrogenation performance of the composite. The non-isothermal dehydrogenation curve shows that the onset temperature of hydrogen release from 4MgH2-NaAlH4-TiH2 is at around 100 °C, which is lower by 50 °C than that of 4MgH2-NaAlH4. The investigation by Kissinger's method indicates that 4MgH2-NaAlH4-TiH2 possesses much lower activation energy (68 kJ mol−1) than 4MgH2-NaAlH4 (159 kJ mol−1), indicating an enhanced dehydrogenation kinetics due to the additional TiH2. TiH2 catalyzes the decomposition of MgH2 and NaAlH4, respectively, and also the reaction between their products during the dehydrogenation process below 375 °C. At temperatures above 375 °C, TiH2 will react with Mg17Al12 to form Al3Ti and liberate contained hydrogen. TiH2 also improved the isothermal hydrogenation kinetics of 4MgH2-NaAlH4 desorbed system. The activation energy of re-hydrogenation for 4MgH2-NaAlH4-TiH2 system was greatly reduced from 161.62 kJ mol−1 H2 to 125.80 kJ mol−1 H2 of 4MgH2-NaAlH4. The kinetics enhancement of hydrogen absorption is probably due to the intermediate phase Al3Ti, which is beneficial to the recombination of MgH2.

In this work, titanium dioxide surface modified montmorillonite (TMC) were prepared by sol–gel method, so as to improve its selective adsorptivity for trivalent chromium ions (Cr3+). When it was applied to remove low concentration of Cr3+(10 mg/L) from wastewater, the remaining concentration of Cr3+ was less than 1.5 mg/L, meeting the emission standard required by the Chinese Environmental protection agency (GB4287-92). The phase, structure and morphology of TMC were determined by means of XRD, CEC, IR, Raman, XPS, SEM, TEM and BET. It was found that titanium dioxide (TiO2) was uniformly dispersed on the surface of montmorillonite (MMT), and the spacing of MMT layer was almost unchanged via filling with Na+, so that the selective adsorptivity of MMT for Cr3+ was achieved. At the same time, theoretical calculations based on first principles and density functional theory confirmed the adsorption selectivity of MMT for Cr3+. In addition, the structural advantages of TMC addressed the shortcomings of MMT surface negative potential that it could not perform adsorption selectivity. Moreover, the adsorptive process of Cr3+ with TMC followed the pesudo-second-order kinetic equation, and Langmuir equation could better describe the adsorption mechanism (the maximum adsorption capacity was 194.1 mg/g). After five cycles, the removing efficiency was still over 89%. Therefore, TMC accompanied with high selective adsorptivity, simple synthesis process, as well as high regenerative performance, had great potential for removing low concentration of Cr3+ from wastewater.

Montmorillonite (MMT), with many excellent features, such as nano-layered structure, ion exchange ability and high hydrophilicity, could be considered as a kind of modified materials, so it is widely applied in many fields. In this study, novel photocatalyst material-TMC, is synthesized via the method of filling cations, accomplishing with prepared by loading TiO2 on the surface of MMT, which is proposed to remove Rhodamine B (Rh-B) via photocatalytic degradation. In the preparing process, the negative potential of MMT plays an important role in uniformly distributing TiO2 as well as limiting the size of distributed particles. Meanwhile, obtaining more oxygen vacancies could be attributed to optimal by screen calcination temperature. In addition, the specific surface area of TMC is measured to be three times larger than that of single TiO2. Furthermore, coupled with UV-DRS, FT-IR, XPS and PL, it is confirmed that Ti-O-Si bonds have been formed, and the narrowest bandgap (2.79 eV) is formed with the sample that calcinated at 450 °C. Meanwhile, the positions of conduction band and valence band with TMC contribute that it reaches higher Fermi level as compared with single TiO2. In addition, the negative potential (on the surface of MMT) acts as effectively extending the recombination time between electrons (e-) and holes (h+), so that the transferred photoelectrons can directly form O2− to degrade Rh-B that adsorbed on the surface of MMT. Finally, the main free radical scavenging experiment is conducted to indicate that O2− and OH are the dominant free radicals that involve in photocatalytic process, and the degradation pathways for Rh-B are speculated with characterization of HPLC-MS.

The reaction mechanism of the organic reagent removing VOCl3 from crude TiCl4 has been explored, which is key to optimize industrial application. In this study, a comprehensive reaction mechanism is conducted via various characterization techniques and computational studies, such as XRD, XPS, Raman, SEM, density functional theory calculations and thermodynamic calculation etc. The results show that the main substance in the residue, which derives from the reaction of organic reagent and crude TiCl4 is amorphous carbon. It is created from organic reagent catalyzied by TiCl4, undergoing reactions including the aromatization, polycondensation and carbonization. Then, the amorphous carbon adsorbs VOCl3 and converts it into insoluble VOCl2 and VCl3. Finally, the insoluble particles are removed via adsorbing by amorphous carbon.

A porous three-dimensional (3D) graphene oxide-montmorillonite/sodium alginate (GO-MMT/SA) aerogel beads have been prepared by a simple method of cross-linking and freeze-drying, which is used to selectively adsorb methylene blue (MB) in aqueous solution. In addition, the properties of GO-MMT/SA aerogel beads are characterized by FTIR, Raman, TG, BET, SEM and XPS. Characterization results show that GO-MMT/SA aerogel beads obtain an integral porous structure and a larger specific surface area. The three-dimensional network of as-prepared aerogel beads is formed by the strong interaction between the –COO– in SA and Ca2+ ions. Interestingly, it is found there are chemical crosslinking and hydrogen bonds among MMT, GO and SA under our experiment condition. In different conditions, a series of adsorption experiments on the GO-MMT/SA aerogel beads for the removal of MB are carried out. GO-MMT/SA aerogel beads show better adsorption capacities toward MB, and poor adsorption capacities for rhodamineB and methyl orange. The pseudo-second-order kinetic equation and Freundlich equation can appropriately describe the adsorption process. Furthermore, the possible adsorption mechanism of GO-MMT/SA aerogel beads for MB is also proposed based on the experimental results.

Epoxy resin was conjugated with zinc oxide nanoparticles (ZnO NPs) to prepare antibacterial zinc oxide-epoxy resin (ZnO-ER) composite. The property of ZnO-ER was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and SEM-energy dispersive X-ray spectroscopy (SEM-EDS) assays. Results showed the presence of ZnO NPs on the surface and cross-sections of ZnO-ER composite. The average thickness of ZnO-ER was 392.38 μm. The strong antibacterial effect of ZnO-ER on the test bacterial mixture derived from spoiled silvery pomfret (Pampus argenteus) was observed using SEM assay. After addition of ZnO-ER for 6 h in the bacterial mixture, cellular membrane integrities of most bacteria were destroyed. High-throughput 16S ribosomal RNA gene sequencing revealed the decreases of both community richness and diversity in the ZnO-ER treated bacterial mixture. As for relative abundances, significant decreases were detected in the phyla Bacteroidetes and Firmicute, while dramatic increase of the phylum Proteobacteria was observed after ZnO-ER treatment. The family of Enterobacteriaceae was predominant in the ZnO-ER treatment. The genera of Providencia and Yersinia showed dramatically high relative abundances. However, the abundances of some specific genera such as Aeromonas and Shewanell, which are related to human infections or food spoilage, were decreased to 0.00% after addition of ZnO-ER for 6 h. When the incubation time of ZnO-ER with the bacterial mixture was prolonged to 24 h, bacteria colony was hardly detected to a negligible level. The results suggest the potential application of ZnO-ER in food packaging to inhibit spoilage bacteria derived from aquatic organisms.

Production of menaquinone-7 (MK-7) by Bacillus subtilis natto is associated with major drawbacks. To address the current challenges in MK-7 fermentation, studying the effect of magnetic nanoparticles on the bacterial cells can open up a new domain for intensified bioprocesses. This article introduces the new concept of application of iron oxide nanoparticles (IONs) as a pioneer tool for MK-7 process intensification. In this order, IONs with the average size of 11 nm were successfully fabricated and characterized for possible in situ removal of target substances from the fermentation media. The prepared particles were used for decoration and immobilization of B. subtilis natto cells. Presence of iron oxide nanoparticles significantly enhanced the MK-7 specific yield (15 %) as compared to the control samples. In addition, fabricated IONs showed a promising ability for in situ recovery of bacterial cells from the fermentation media with more than 95 % capture efficiency. Based on the results, IONs can be implemented successfully as a novel tool for MK-7 production. This study provides a considerable interest for industrial application of magnetic nanoparticles and their future role in designing an intensified biological process.

Industrial production of menaquione-7 by Bacillus subtilis natto is associated with major drawbacks. To address the current challenges in menaquione-7 fermentation, studying the effect of magnetic nanoparticles on the bacterial cells can open up a new domain for intensified menqainone-7 process. This article introduces the new concept of production and application of l-lysine coated iron oxide nanoparticles (l-Lys@IONs) as a novel tool for menaquinone-7 biosynthesis. l-Lys@IONs with the average size of 7 nm were successfully fabricated and were examined in a fermentation process of l-Lys@IONs decorated Bacillus subtilis natto. Based on the results, higher menaquinone-7 specific yield was observed for l-Lys@IONs decorated bacterial cells as compared to untreated bacteria. In addition, more than 92% removal efficacy was achieved by using integrated magnetic separation process. The present study demonstrates that l-Lys@IONs can be successfully applied during a fermentation of menaquinone-7 without any negative consequences on the culture conditions. This study provides a novel biotechnological application for IONs and their future role in bioprocess intensification.