Nano sensors: Designing and Fabrication, Applications for flexible devices and Future Perspectives

2020 ◽  
Vol 16 ◽  
Author(s):  
Muhammad Bilal Tahir ◽  
Aleena Shoukat ◽  
Tahir Iqbal ◽  
Asma Ayub ◽  
Saff-e Awal ◽  
...  

: The field of nanosensors has been gaining a lot of attention due to its properties such as mechanical and electrical ever since its first discovery by Dr. Wolter and first mechanical sensor in 1994. The rapidly growing demand of nanosensors has become profitable for a multidisciplinary approach in designing and fabrication of materials and strategies for potential applications. Frequent stimulating advancements are being suggested and established in recent years and thus heading towards multiple applications including food safety, healthcare, environmental monitoring, and biomedical research. Nanofabrication being an efficient method has been used in different industries like medical pharmaceutical for their complex functional geometry at a lower scale. These nanofabrications apply through different methods. There are five most commonly known methods which are frequently used, including top-down lithography, molecular self-assembly, bottom-up assembly, heat and pull method for fabrication of biosensors, etching for fabrication of nanosensors etc. Nanofabrication help at the nanoscale to design and work with small models. But these models due to their small size and being sensitive need more care for use as well as more training and experience to do work with. All methods used for nanofabrication are good and helpful. But more preferred is molecular self-assembly as it is helpful in mass production. Nanofabrication has become an emerging and developing field and it assumed that in near future our world is known by the new devices of nanofabrication.

2019 ◽  
Vol 10 (45) ◽  
pp. 6116-6121 ◽  
Author(s):  
Tan Ji ◽  
Lei Xia ◽  
Wei Zheng ◽  
Guang-Qiang Yin ◽  
Tao Yue ◽  
...  

We present a new family of porphyrin-functionalized coordination star polymers prepared through combination of coordination-driven self-assembly and post-assembly polymerization. Their self-assembly behaviour in water and potential for photodynamic therapy were demonstrated.


2019 ◽  
Vol 24 (32) ◽  
pp. 3739-3757 ◽  
Author(s):  
Chandrabose Selvaraj ◽  
Sanjeev K. Singh

Nucleic acid is the key unit and a predominant genetic material for interpreting the fundamental basis of genetic information in an organism and now it is used for the evolution of a novel group of therapeutics. To identify the potential impact on the biological science, it receives high recognition in therapeutic applications. Due to its selective recognition of molecular targets and pathways, DNA significantly imparts tremendous specificity of action. Examining the properties of DNA holds numerous advantages in assembly, interconnects, computational elements, along with potential applications of DNA self-assembly and scaffolding include nanoelectronics, biosensors, and programmable/autonomous molecular machines. The interaction of low molecular weight, small molecules with DNA is a significant feature in pharmacology. Based on the mode of binding mechanisms, small molecules are categorized as intercalators and groove binders having a significant role in target-based drug development. The understanding mechanism of drug-DNA interaction plays an important role in the development of novel drug molecules with more effective and lesser side effects. This article attempts to outline those interactions of drug-DNA with both experimental and computational advances, including ultraviolet (UV) -visible spectroscopy, fluorescent spectroscopy, circular dichroism, nuclear magnetic resonance (NMR), molecular docking and dynamics, and quantum mechanical applications.


2021 ◽  
Vol 22 (9) ◽  
pp. 4533
Author(s):  
Tomoyuki Koga ◽  
Shinya Kingetsu ◽  
Nobuyuki Higashi

Self-assembly of artificial peptides has been widely studied for constructing nanostructured materials, with numerous potential applications in the nanobiotechnology field. Herein, we report the synthesis and hierarchical self-assembly of collagen-mimetic peptides (CMPs) bearing various aromatic groups at the N-termini, including 2-naphthyl, 1-naphtyl, anthracenyl, and pyrenyl groups, into nanofibers. The CMPs (R-(GPO)n: n > 4) formed a triple helix structure in water at 4 °C, as confirmed via CD analyses, and their conformations were more stable with increasing hydrophobicity of the terminal aromatic group and peptide chain length. The resulting pre-organized triple helical CMPs showed diverse self-assembly into highly ordered nanofibers, reflecting their slight differences in hydrophobic/hydrophilic balance and configuration of aromatic templates. TEM analysis demonstrated that 2Np-CMPn (n = 6 and 7) and Py-CMP6 provided well-developed natural collagen-like nanofibers and An-CMPn (n = 5–7) self-assembled into rod-like micelle fibers. On the other hand, 2Np-CMP5 and 1Np-CMP6 were unable to form nanofibers under the same conditions. Furthermore, the Py-CMP6 nanofiber was found to encapsulate a guest hydrophobic molecule, Nile red, and exhibited unique emission behavior based on the specific nanostructure. In addition to the ability of CMPs to bind small molecules, their controlled self-assembly enables their versatile utilization in drug delivery and wavelength-conversion nanomaterials.


2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
David M. Smith ◽  
Verena Schüller ◽  
Carsten Forthmann ◽  
Robert Schreiber ◽  
Philip Tinnefeld ◽  
...  

Nanometer-sized polyhedral wire-frame objects hold a wide range of potential applications both as structural scaffolds as well as a basis for synthetic nanocontainers. The utilization of DNA as basic building blocks for such structures allows the exploitation of bottom-up self-assembly in order to achieve molecular programmability through the pairing of complementary bases. In this work, we report on a hollow but rigid tetrahedron framework of 75 nm strut length constructed with the DNA origami method. Flexible hinges at each of their four joints provide a means for structural variability of the object. Through the opening of gaps along the struts, four variants can be created as confirmed by both gel electrophoresis and direct imaging techniques. The intrinsic site addressability provided by this technique allows the unique targeted attachment of dye and/or linker molecules at any point on the structure's surface, which we prove through the superresolution fluorescence microscopy technique DNA PAINT.


2021 ◽  
Vol 25 ◽  
Author(s):  
Jun Zheng ◽  
Yan Mei Jin ◽  
Xi Nan Yang ◽  
Lin Zhang ◽  
Dao Fa Jiang ◽  
...  

: Single-crystal X-ray diffraction analysis, nuclear magnetic resonance (NMR), and other characterization methods are used to characterize the complexes formed by cyclopentano-cucurbit[6]uril (abbreviated as CyP6Q[6]) as a host interacting with p-aminobenzenesulfonamide (G1), 4,4'-diaminobiphenyl (G2), and (E)-4,4'-diamino-1,2-diphenylethene (G3) as guests, respectively. The experimental results show that these three aromatic amine molecules have the same interaction mode with CyP6Q[6], interacting with its negatively electric potential portals. The supramolecular interactions include non-covalent interactions of hydrogen bonding and ion-dipole between host and guest molecules. CdCl2 acts as a structureinducing agent to form self-assemblies of multi-dimensional and multi-level supramolecular frameworks that may have potential applications in various functional materials.


2003 ◽  
Vol 60 (2) ◽  
pp. 409-416 ◽  
Author(s):  
Gerd Sparovek ◽  
Isabella Clerici De Maria

Erosion tolerance is the most multidisciplinary field of soil erosion research. Scientists have shown lack in ability to adequately analyze the huge list of variables that influence soil loss tolerance definitions. For these the perspectives of erosion made by farmers, environmentalists, society and politicians have to be considered simultaneously. Partial and biased definitions of erosion tolerance may explain not only the polemic nature of the currently suggested values but also, in part, the nonadoption of the desired levels of erosion control. To move towards a solution, considerable changes would have to occur on how this topic is investigated, especially among scientists, who would have to change methods and strategies and extend the perspective of research out of the boundaries of the physical processes and the frontiers of the academy. A more effective integration and communication with the society and farmers, to learn about their perspective of erosion and a multidisciplinary approach, integrating soil, social, economic and environmental sciences are essential for improved erosion tolerance definitions. In the opinion of the authors, soil erosion research is not moving in this direction and a better understanding of erosion tolerance is not to be expected in the near future.


2018 ◽  
Vol 74 (11) ◽  
pp. 1434-1439
Author(s):  
Hong-Tao Zhang ◽  
Xiao-Long Wang

In recent years, much initial interest and enthusiasm has focused on the self-assembly of coordination polymers due to the aesthetics of their crystalline architectures and their potential applications as new functional materials. As part of an exploration of chiral coordination polymers, a new twofold interpenetrated two-dimensional (2D) coordination polymer, namely, poly[[tetraaquabis[μ3-(2R,2′R)-2,2′-(benzene-1,4-dicarboxamido)dipropionato-κ5 O,O′:O′′,O′′′:O′′]dicadmium(II)] trihydrate], {[Cd2(C14H14N2O6)2(H2O)4]·3H2O} n , has been synthesized by the reaction of Cd(CH3COO)2·2H2O with the designed ligand (2R,2′R)-2,2′-(benzene-1,4-dicarboxamido)dipropionic acid (H2 L). The compound has been structurally characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction and single-crystal X-ray diffraction analysis. In the crystal structure, each CdII cation binds to three carboxylate groups from two crystallographically independent L 2− dianions. Four carboxylate groups link two crystallographically independent cadmium cations into a 4,4-connected secondary building unit (SBU). The resulting SBUs are extended into a two-dimensional folding sheet via the terephthalamide moiety of the ligand as a spacer, which can be simplified as a (4,4)-connected 4,4L15 net with the point symbol (3.53.62)(32.52.62). In the lattice, two independent folding sheets interpenetrate each other to yield a double-sheet layer. The resulting 2D layers pack in parallel arrays through intermolecular hydrogen bonds and interlayer π–π interactions. The thermal stability and photoluminescence properties of the title compound have been investigated and it exhibits an enhanced fluorescence emission and a longer lifetime compared with free H2 L.


2020 ◽  
Vol 7 ◽  
Author(s):  
Audrey A. Watkins ◽  
Osama R. Bilal

Controlling infrasound signals is crucial to many processes ranging from predicting atmospheric events and seismic activities to sensing nuclear detonations. These waves can be manipulated through phononic crystals and acoustic metamaterials. However, at such ultra-low frequencies, the size (usually on the order of meters) and the mass (usually on the order of many kilograms) of these materials can hinder its potential applications in the infrasonic domain. Here, we utilize tunable lattices of repelling magnets to guide and sort infrasound waves into different channels based on their frequencies. We construct our lattices by confining meta-atoms (free-floating macroscopic disks with embedded magnets) within a magnetic boundary. By changing the confining boundary, we control the meta-atoms’ spacing and therefore the intensity of their coupling potentials and wave propagation characteristics. As a demonstration of principle, we present the first experimental realization of an infrasound phonon demultiplexer (i.e., guiding ultra-low frequency waves into different channels based on their frequencies). The realized platform can be utilized to manipulate ultra-low frequency waves, within a relatively small volume, while utilizing negligible mass. In addition, the self-assembly nature of the meta-atoms can be key in creating re-programmable materials with exceptional nonlinear properties.


2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Cheng Zhang ◽  
Romain Grossier ◽  
Nadine Candoni ◽  
Stéphane Veesler

AbstractThis review examines the preparation of alginate hydrogel microparticles by using droplet-based microfluidics, a technique widely employed for its ease of use and excellent control of physicochemical properties, with narrow size distribution. The gelation of alginate is realized “on-chip” and/or “off-chip”, depending on where cross-linkers are introduced. Various strategies are described and compared. Microparticle properties such as size, shape, concentration, stability and mechanical properties are discussed. Finally, we consider future perspectives for the preparation of hydrogel microparticles and their potential applications.


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