scholarly journals Design, synthesis, and characterization of novel nanowire structures for photovoltaics and intracellular probes

2011 ◽  
Vol 83 (12) ◽  
pp. 2153-2169 ◽  
Author(s):  
Bozhi Tian ◽  
Charles M. Lieber

Semiconductor nanowires (NWs) represent a unique system for exploring phenomena at the nanoscale and are expected to play a critical role in future electronic, optoelectronic, and miniaturized biomedical devices. Modulation of the composition and geometry of nanostructures during growth could encode information or function, and realize novel applications beyond the conventional lithographical limits. This review focuses on the fundamental science aspects of the bottom-up paradigm, which are synthesis and physical property characterization of semiconductor NWs and NW heterostructures, as well as proof-of-concept device concept demonstrations, including solar energy conversion and intracellular probes. A new NW materials synthesis is discussed and, in particular, a new “nano-tectonic” approach is introduced that provides iterative control over the NW nucleation and growth for constructing 2D kinked NW superstructures. The use of radial and axial p-type/intrinsic/n-type (p-i-n) silicon NW (Si-NW) building blocks for solar cells and nanoscale power source applications is then discussed. The critical benefits of such structures and recent results are described and critically analyzed, together with some of the diverse challenges and opportunities in the near future. Finally, results are presented on several new directions, which have recently been exploited in interfacing biological systems with NW devices.

2014 ◽  
Vol 70 (a1) ◽  
pp. C1223-C1223
Author(s):  
Jason Benedict ◽  
Ian Walton ◽  
Dan Patel ◽  
Jordan Cox

Metal-organic Frameworks (MOFs) remain an extremely active area of research given the wide variety of potential applications and the enormous diversity of structures that can be created from their constituent building blocks. While MOFs are typically employed as passive materials, next-generation materials will exhibit structural and/or electronic changes in response to applied external stimuli including light, charge, and pH. Herein we present recent results in which advanced photochromic diarylethenes are combined with MOFs through covalent and non-covalent methods to create photo-responsive permanently porous crystalline materials. This presentation will describe the design, synthesis, and characterization of next-generation photo-switchable diarylethene based ligands which are subsequently used to photo-responsive MOFs. These UBMOF crystals are, by design, isostructural with previously reported non-photoresponsive frameworks which enables a systematic comparison of their physical and chemical properties. While the photoswitching of the isolated ligand in solution is fully reversible, the cycloreversion reaction is suppressed in the UBMOF single crystalline phase. Spectroscopic evidence for thermally induced cycloreversion will be presented, as well as a detailed analysis addressing the limits of X-ray diffraction techniques applied to these systems.


Biomolecules ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1449
Author(s):  
Martyna Szymańska ◽  
Izabela Pospieszna-Markiewicz ◽  
Martyna Mańka ◽  
Małgorzata Insińska-Rak ◽  
Grzegorz Dutkiewicz ◽  
...  

Generation of well-defined potential metallotherapeutics for cancer treatment, one of the most population-threatening diseases, is challenging and an active area of modern research in view of their unique properties and thus multiple possible pathways of action in cells. Specifically, Schiff base ligands were recognized as very promising building blocks for the construction of stable and active complexes of numerous geometries and topologies. Incorporation of Ag(I) ions allows for the formation of flat complexes with potential unoccupied coordination sites, thus giving rise to specific interactions between the metallotherapeutic and biomolecule of interest. Herein, we present the design, synthesis and characterization of new Schiff base ligand L and its Ag(I) bimetallic complex [Ag2L2]2+ with two planar moieties formed around the metal ions and connected through cyclohexane rings, confirmed by X-ray measurements. The compounds were described in context of their potential use as anticancer drugs through DNA and BSA binding pathways by several spectroscopic methods (CD, UV-Vis, fluorescence). We revealed that both, L and [Ag2L2]2+, interact with similar affinity with CT-DNA (Kb~106 M−1), while they differ in the type and strength of interactions with the model albumin–BSA. [Ag2L2]2+ binds BSA in both a dynamic and static manner with the Ksv = 8.8 × 104 M−1 in the Trp-134 and Trp-213 sites, whereas L interacts with BSA only dynamically (KSV = 2.4 × 104 M−1). This found further confirmation in the CD studies which revealed a reduction in α-helix content in the albumin of 16% in presence of [Ag2L2]2+.


2020 ◽  
Vol 27 (8) ◽  
pp. 688-697
Author(s):  
Yu Chen ◽  
Kai Tao ◽  
Wei Ji ◽  
Pandeeswar Makam ◽  
Sigal Rencus-Lazar ◽  
...  

Supramolecular self-assembled functional materials comprised of cyclic dipeptide building blocks have excellent prospects for biotechnology applications due to their exceptional structural rigidity, morphological flexibility, ease of preparation and modification. Although the pharmacological uses of many natural cyclic dipeptides have been studied in detail, relatively little is reported on the engineering of these supramolecular architectures for the fabrication of functional materials. In this review, we discuss the progress in the design, synthesis, and characterization of cyclic dipeptide supramolecular nanomaterials over the past few decades, highlighting applications in biotechnology and optoelectronics engineering.


2015 ◽  
Vol 17 (8) ◽  
pp. 1922-1925 ◽  
Author(s):  
Tetiana Druzhenko ◽  
Olexandr Denisenko ◽  
Yuri Kheylik ◽  
Sergey Zozulya ◽  
Svitlana S. Shishkina ◽  
...  

2020 ◽  
Vol 3 (1) ◽  
pp. 30-33
Author(s):  
Muthulakshmi M ◽  
Madhumitha G

Nanotechnology is a field of applied science focused on design, synthesis and characterization of nanomaterials. The nickel and magnesium have improved their applications in transparent electrodes and nano electronics. In addition, magnesium oxide has moisture resistance and high melting point properties. In the present work has been carried out in the development of green crystalline powder of nickel doped magnesium oxide nanoparticles by Co-precipitation method, from the mixture of nickel chloride and magnesium chloride with KOH as solvent. From the XRD results, crystalline size of the particle can be observed. Spherical structure of Ni doped MgO nanoparticles were indicated by SEM results and powdered composition of samples were obtained from FTIR. EDAX represents the peak composition of the nanoparticle. The above analytical techniques have confirmed that the Ni doped MgO nanoparticles obtained from the mixture of NiCl2 and MgCl2.


2019 ◽  
Vol 16 (12) ◽  
pp. 1348-1353
Author(s):  
Huanhuan Qu ◽  
Baixue Li ◽  
Jingyi Yang ◽  
Huaiwen Liang ◽  
Meixia Li ◽  
...  

Background: Disaccharide core 1 (Galβ1-3GalNAc) is a common O-glycan structure in nature. Biochemical studies have confirmed that the formation of the core 1 structure is an important initial step in O-glycan biosynthesis and it is of great importance for human body. Objective: Our study will provide meaningful and useful sights for O-glycan synthesis and their bioassay. And all the synthetic glycosides would be used as intermediate building blocks in the scheme developed for oligosaccharide construction. Methods: In this article, we firstly used chemical procedures to prepare core 1 and its derivative, and a novel disaccharide was efficiently synthesized. The structures of the synthesized compounds were elucidated and confirmed by 1H NMR, 13C NMR and MS. Then we employed three human gut symbionts belonging to Bacteroidetes, a predominantphyla in the distal gut, as models to study the bioactivity of core 1 and its derivative on human gut microbiota. Results: According to our results, both core 1 and derivative could support the growth of B. fragilis, especially the core 1 derivative, while failed to support the growth of B. thetaiotaomicron and B. ovatus. Conclusion: This suggested that the B. fragilis might have the specificity glycohydrolase to cut the glycosidic bond for acquiring monosaccharide.


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