유-무기 혼성 나노 꽃의 생물공학적 응용 연구 동향

정민수(Minsoo Chung),김문일(Moon Il Kim) 한국생물공학회 2018 KSBB Journal Vol.33 No.2

Organic-inorganic hybrid nanostructures with flower-like morphology, so called nanoflowers, have received an increasing attention due to their capability to greatly enhance the activity, stability, and durability of entrapped biomolecules, which is much better than those from the conventional immobilization strategies. These hybrid nanoflowers are simply synthesized via the incubation at room temperature but show high surface roughness and large surface-tovolume ratio, which enables high loading capacity of biomolecules without severe mass transfer limitation. Based on the advantageous features, they have been applied in the field of biotechnology such as biosensor, biofuel cell, and protein digestion. To highlight the research progress on organic-inorganic hybrid nanoflowers, this review discusses the synthetic methods, structural characteristics, and recent applications of the nanoflowers. Finally, we address the future prospects of the hybrid nanoflowers in biotechnology industry, particularly for sensing, medicine, and catalyst.

Intrinsic peroxidase-like activity of sonochemically synthesized protein copper nanoflowers and its application for the sensitive detection of glucose

Batule, Bhagwan S.,Park, Ki Soo,Gautam, Shreedhar,Cheon, Hong Jae,Kim, Moon Il,Park, Hyun Gyu Elsevier 2019 Sensors and actuators. B Chemical Vol.283 No.-

<P><B>Abstract</B></P> <P>We have found that protein-inorganic hybrid nanoflowers, prepared by an ultrafast sonication-mediated self-assembly of proteins and copper ions, exhibit an intrinsic peroxidase-mimicking activity, which is significantly higher than that of control materials formed in the absence of proteins. By employing glucose oxidase (GOx) as a protein component, the novel synthetic method was applied to construct GOx copper nanoflowers capable of promoting glucose-induced cascade enzymatic reactions. In the presence of target glucose, GOx, entrapped in the hybrid nanoflowers, generates H<SUB>2</SUB>O<SUB>2</SUB> through its catalytic action; this subsequently induces peroxidase-mediated oxidation by the hybrid nanoflowers to convert the selected substrate, Amplex UltraRed (AUR), to a highly fluorescent product. Using this strategy, the target glucose was reliably determined down to 3.5 μM with high selectivity. The practical diagnostic utility of the assay system was also verified by using it to detect glucose in human blood serum. This sonochemical strategy has great potential to be extended for the construction of various oxidative enzyme-inorganic hybrid nanoflowers that are capable of detecting clinically important target molecules.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Sonochemically synthesized protein-inorganic hybrid nanoflowers exhibited an intrinsic peroxidase-like activity. </LI> <LI> Glucose oxidase-copper hybrid nanoflowers possessed dual enzymatic activity. </LI> <LI> The nanoflower-based biosensor showed high selectivity and sensitivity for glucose detection. </LI> <LI> Diverse glucose levels in human blood were successfully determined with excellent reproducibility and reliability. </LI> </UL> </P>

Monodispersed 3D MnWO4-TiO2 composite nanoflowers photocatalysts for environmental remediation

M. Shamshi Hassan,Touseef Amna,Salem S. Al-Deyab,김현철,길명섭 한국물리학회 2015 Current Applied Physics Vol.15 No.6

Pollutants from textile industries into water-bodies have caused huge environmental hazards. The semiconductor mediated photocatalytic purification of polluted water is a promising environmental remediation technology. In the present study MnWO4-TiO2 composite nanoflowers endowed with efficient photocatalytic activity have been successfully synthesized by facile hydrothermal approach. XRD, SEM, TEM, EDX spectroscopy and UV-DRS were used to characterize the as-synthesized samples. The average size of composite nanoflower is ~2 μmwhile the nanorods constructing the nanoflowers had the average diameters of 90 nm. The photocatalytic activity of the MnWO4-TiO2 nanoflowers for the degradation of methyl orange (MO) in visible light was much higher than of pristine TiO2 nanorods and MnWO4 nanoflowers respectively. The superior photocatalytic activity could be attributed to the formation of a MnWO4-TiO2 heterojunction in the MnWO4-TiO2 nanoflowers.

Hierarchical, Dual-Scale Structures of Atomically Thin MoS₂ for Tunable Wetting

Choi, Jonghyun,Mun, Jihun,Wang, Michael Cai,Ashraf, Ali,Kang, Sang-Woo,Nam, SungWoo American Chemical Society 2017 NANO LETTERS Vol.17 No.3

<P>Molybdenum disulfide (MoS2), a well-known solid lubricant for low friction surface coatings, has recently drawn attention as an analogue two-dimensional (2D) material beyond graphene. When patterned to produce vertically grown, nanoflower-structures, MoS2 shows promise as a functional material for hydrogen evolution catalysis systems, electrodes for alkali metal-ion batteries, and field-emission arrays. Whereas the wettability of graphene has been substantially investigated, that of MoS, structures, especially nanoflowers, has remained relatively unexplored despite MoS2 nanoflower's potential in future applications. Here, we demonstrate that the wettability of MoS2 can be controlled by multiscale modulation of surface roughness through (1) tuning of the nanoflower structures by chemical vapor deposition synthesis and (2) tuning of microscale topography via mechanical strain. This multiscale modulation offers broadened tunability (80-155 degrees) compared to single-scale tuning (90-130 degrees). In addition, surface adhesion, determined from contact angle hysteresis (CAH), can also be tuned by multiscale surface roughness modulation, where the CAH is changed in range of 20-40 degrees Finally, the wettability of crumpled MoS, nanoflowers can be dynamically and reversibly controlled through applied strain (similar to 115-150 with 0-200% strain), and remains robust over 1000 strain cycles. These studies on the tunable wettability of MoS, will contribute to future MoS2-based applications, such as tunable wettability coatings for desalination and hydrogen evolution.</P>

Fabrication of efficient CdS nanoflowers-decorated TiO₂ nanotubes array heterojunction photoanode by a novel synthetic approach for solar hydrogen production

Shinde, P.S.,Park, J.W.,Mahadik, M.A.,Ryu, J.,Park, J.H.,Yi, Y.J.,Jang, J.S. Pergamon Press ; Elsevier Science Ltd 2016 International journal of hydrogen energy Vol.41 No.46

<P>A nanocomposite heterojunction photoanode involving CdS nanoflowers (NFs) and one-dimensional TiO2 nanotube (NT) arrays was reported. The self-assembled TiO2 NT arrays were fabricated by an anodization method and the surface of TiO2 NT arrays was decorated with CdS NFs by employing hydrothermal method for the first time. The CdS NF morphology was optimized by controlling the hydrothermal reaction time from 0 to 72 h. Field-emission scanning electron microscopy (FESEM) study of the CdS-NF/TiO2-NT photoanode revealed good coverage of hydrothermally grown CdS NFs on the surface of TiO2 NT arrays. The photoelectrochemical measurements were performed under 100 mW cm(-2) illumination using polysulfide electrolyte. A 5.5-fold photocurrent enhancement was observed for the CdS-NF/TiO2-NT array photoanode synthesized with a 48 h CdS hydro thermal reaction compared to a pristine TiO2 NT array film. Annealing of TiO2 NTs as well as CdS NFs led to further improvement in the photocurrent on account of greater crystallinity, significantly higher visible light photon absorption and improved interface properties between CdS and TiO2. These findings were supported by optical absorption, electrochemical impedance spectroscopy and Mott-Schottky analyses. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.</P>

Diversified component incorporated hybrid nanoflowers: A versatile material for biosensing and biomedical applications

Thinh Viet Dang,김문일 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.2

Organic-inorganic hybrid nanoflowers (HNFs) have generated widespread research interest owing to their properties to efficiently entrap organic components like protein or enzyme within their nanostructured matrices, yielding high activity, stability, and recyclability. Recently, much effort has been devoted to developing advanced HNFs composed of diversified components, such as multiple proteins, nanoparticles, polymers, and nucleic acids, to achieve different functionalities enabling extended applications. Compared to the conventional HNFs primarily serving as immobilization supports for enzyme, diversified component incorporated HNFs can have unique multiple functionalities, essentially for developing novel biosensing and biomedical strategies. Herein, an overview for the recent advances on diversified components incorporated HNFs is presented with an emphasis on the potential biotechnological applications. Synthetic strategies, structural characteristics, and unique properties of diverse HNFs are discussed with representative studies, demonstrating the versatility of the HNFs. Current challenges and future opportunities of the HNFs are also discussed.

Influence of rare earth elements on porosity controlled synthesis of MnO₂ nanostructures for supercapacitor applications

Rajagopal, Rajesh,Ryu, Kwang-Sun Pergamon Press 2018 Electrochimica Acta Vol. No.

<P><B>Abstract</B></P> <P>Nanostructured MnO<SUB>2</SUB> was synthesized using a facile hydrothermal technique with potassium permanganate as a precursor. Rare earth elements, lanthanum and cerium, were used to control the porosity of the MnO<SUB>2</SUB> nanostructures. Nanorod-, nanoflower-, nanoneedle-, and nanoneedles/nanopetal-shaped MnO<SUB>2</SUB> nanostructures were synthesized by changing the concentration of the rare earth elements. The as-synthesized MnO<SUB>2</SUB> nanorods, La – MnO<SUB>2</SUB> nanoneedles, Ce – MnO<SUB>2</SUB> nanoflowers, and La/Ce – MnO<SUB>2</SUB> nanoneedles/nanopetals were examined using a range of physico chemical characterization techniques. Scanning electron microscopy and transmission electron microscopy – energy dispersive X-ray spectroscopy confirmed the morphology of the MnO<SUB>2</SUB> nanostructures and the elemental distribution. The porous natures of the synthesized MnO<SUB>2</SUB> nanostructures were analyzed by nitrogen adsorption technique. The electrochemical behavior of the MnO<SUB>2</SUB> nanostructures was examined by cyclic voltammetry, charge – discharge and electrochemical impedance spectroscopy tests. The La/Ce – MnO<SUB>2</SUB> nanoneedles/nanopetals electrode exhibited a high specific capacitance of 825 F g<SUP>−1</SUP> at an applied current density of 10 A g<SUP>−1</SUP>. The La/Ce – MnO<SUB>2</SUB> nanoneedles/nanopetals were also mixed with 5, 10, 15 and 20 wt% of rGO nanosheets to enhance the electrochemical behavior. The 20 rGO@La/Ce – MnO<SUB>2</SUB> sample showed extraordinary electrochemical behavior; the calculated specific capacitance was 1165 F g<SUP>−1</SUP> at an applied current density of 10 A g<SUP>−1</SUP>. A 20 rGO@La/Ce – MnO<SUB>2</SUB> and activated carbon asymmetric supercapacitor coin cell device exhibited ∼93% capacitance retention after 1000 cycles. These results highlight the potential of 20 rGO@La/Ce – MnO<SUB>2</SUB> as an electrode material for supercapacitor applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Manganese oxide nanostructures were synthesized by hydrothermal process. </LI> <LI> Lanthanum and cerium used to control the porosity of manganese oxide. </LI> <LI> La/Ce mixed MnO<SUB>2</SUB> nanoneedles/nanopetals showing good electrochemical behavior. </LI> <LI> rGO mixed La/Ce – MnO<SUB>2</SUB> was prepared to improve the storage capacity. </LI> <LI> 20rGO@ La/Ce – MnO<SUB>2</SUB> electrode exhibited high specific capacitance of 1165 F g<SUP>−1</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Silver Nanoflower를 이용한 유연 열계면소재

서대우(Daewoo Suh),이상훈(Sanghoon Lee),Chenchen Xu,백승현(Seunghyun Baik) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.12

Preparation of glutaraldehyde-treated lipase-inorganic hybrid nanoflowers and their catalytic performance as immobilized enzymes

Lee, H.R.,Chung, M.,Kim, M.I.,Ha, S.H. IPC Science and Technology Press ; Elsevier Scienc 2017 Enzyme and microbial technology Vol.105 No.-

<P>The use of protein-inorganic hybrid nanoflowers for the immobilization of enzymes has received a significant degree of attention owing to their capability to retain high enzymatic activity and stability. However, the relative lack of reusability due to the weakness of the flower-like structure has limited their practical applications. Herein, we have developed a simple but efficient method to synthesize highly robust enzyme-inorganic hybrid nanoflowers,which relies on further crosslinking of the enzyme molecules entrapped in the hybrid nanoflowers by treatment with glutaraldehyde (GA). By employing lipase from Candida rugosa as a model enzyme with copper phosphate during 3 days incubation followed by the additional GA treatment for only 1 h, we could successfully synthesize GA-treated lipase nanoflowers having similar flower-like morphology and hydrolytic activity (ca. 95% compared with the free lipase) as conventionally synthesized lipase nanoflowers without GA treatment. Importantly, the conventional lipase nanoflowers seemed not to be reusable because they lost most of their activity (90%) after recycling 4 times, whereas GA-treated lipase nanoflowers exhibited higher retention of their initial activity (over 70%) after 4 reuses, which was also accompanied by an efficient maintenance of their flower-like morphology. Based on our results, we expect that this simple GA-mediated strategy to synthesize enzyme-inorganic hybrid nanoflowers can be readily extended to other enzymes for various biotechnological applications.</P>

Fabrication of boron-doped nanocrystalline diamond nanoflowers based on 3D Cu(OH)2 dendritic architectures

심희준,홍석인,이승구,임대순,진준언,황성우 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.60 No.5

Hot-filament chemical vapor deposition (HFCVD) was used to prepare boron-doped nanocrystalline diamond (BDND) nanoflowers on a Cu substrate with a Cu(OH)2 dendritic architecture that had been formed by using electrostatic self-assembly (ESA) method with nanodiamond particles. The formation of diamond nanoflowers is controlled by the reaction time between the Cu(OH)2 nanoflowers and the polymeric linker for the electrostatic attachment of nanodiamonds and by the deposition time for CVD diamond growth with a high nucleation density. Through analysis by field emission scanning electron microscopy (FESEM) and Raman spectroscopy, the optimal conditions for the synthesis of BDND nanoflowers are determined, and a possible explanation is provided.