scholarly journals An Updated Review on Nanomaterials for Biomedical Advancements: Concepts and Applications

2021 ◽  
Vol 14 (4) ◽  
pp. 1428-1434
Author(s):  
Krishnendu Adhikary
Keyword(s):  
Molecular Level ◽  
Response Times ◽  
Lateral Displacement ◽  
High Surface ◽  
High Surface Area ◽  
Diagnostic Techniques ◽  
Biological Molecules ◽  
Deterministic Lateral Displacement ◽  
Type Mode ◽  
Pharmaceutical Industries

The sphere of Nanotechnology encompasses most of our lives and houses biomedicine and biomedical advancements. Nanoparticles owing to their minuscule sizes and due to various physicochemical and electrical properties have been exploited in pharmaceutical industries, agriculture, packaging, cosmetic, food industries. Nanomedicine is a laboratory-designed molecular-level pharmaceutical material that has revolutionized diagnostic techniques and therapeutics. Nanoscience and nanotechnology and their wide applications have become spread field worldwide because nanomaterials have novel and unique properties. Nanotechnology involves understanding and manipulating materials normally in the size range of 1 to 100 nm, where they show completely novel physicochemical properties from their bulk counterpart. The capacity to study compounds at the molecular level has aided the hunt for materials with exceptional qualities for medical applications. Nanotechnology in recent days is applied in the designing of nano biosensors. Nanobiosensors are biological molecules immobilized onto the surface of a signal transducer. The application of nano biosensors in the field of disease detection has increased in recent years which has influenced in research of cancer and biosensing. Due to the high surface area of nanoparticles, they are important in the production of nano biosensors with high levels of sensitivity and diminish the response times. However, a comprehensive review regarding the type, mode of function, and their application in various diseases is missing. Nano Deterministic lateral displacement technology that provided exosome splitting based on size differences has resulted in providing the much-needed boost to cancer research. The time taken for cancer screening has been reduced drastically. that This review aims to describe the utilization of nano deterministic lateral displacement technology, nano biosensors, and their applications in certain disease diagnoses.

Molecular Architecture and its role in Silica Sol-Gel Polymerization

1990 ◽  
Vol 180 ◽  
Author(s):  
P. C. Cagle ◽  
W. G. Klemperer ◽  
C. A. Simmons
Keyword(s):  
Molecular Level ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Silica Sol ◽  
Molecular Architecture ◽  
Model Studies ◽  
Large Size ◽  
Neutral Conditions ◽  
Very High

ABSTRACTSol-gel polymerization of [Si8O12](OCH3)8 in CH3CN under neutral conditions yields very high surface area (SBET > 900 m2/g) xerogels. This property is seen to result from the structure of the gel on the molecular level. According to N2 adsorption studies, model studies, and TEM studies, the large size and rigidity of the cubic [Si8O12] core structure leads to polymers whose rigidity inhibits extensive crosslinking of the type observed in orthosilicate derived xerogels.

scholarly journals Three-Dimensional Large-Pore Covalent Organic Framework with Stp Topology

2020 ◽  
Author(s):  
Hui Li, ◽  
ding jiehua ◽  
Xinyu Guan ◽  
Fengqian Chen ◽  
Cuiyan Li ◽  
...  
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Biological Molecules ◽  
Low Density ◽  
Large Protein ◽  
Crystalline Materials ◽  
Crystalline Polymers ◽  
Large Pore ◽  
Large Pore Size

Three-dimensional (3D) covalent organic frameworks (COFs) are excellent porous crystalline polymers for numerous applications, but their building units and topological nets have been limited. Herein we report the first 3D large-pore COF with <b>stp</b> topology constructed with a 6-connected triptycene-based monomer. The new COF (termed JUC-564) has high surface area (up to 3300 m<sup>2 </sup>g<sup>-1</sup>), the largest pore (43 Å) among 3D COFs, and record-breaking low density in crystalline materials (0.108 g cm<sup>-3</sup>). The large pore size of JUC-564 is confirmed by the incorporation of a large protein. This study expands the structural varieties of 3D COFs as well as their applications for adsorption and separation of large biological molecules.

scholarly journals Three-Dimensional Large-Pore Covalent Organic Framework with Stp Topology

2020 ◽  
Author(s):  
Hui Li, ◽  
ding jiehua ◽  
Xinyu Guan ◽  
Fengqian Chen ◽  
Cuiyan Li ◽  
...  
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Biological Molecules ◽  
Low Density ◽  
Large Protein ◽  
Crystalline Materials ◽  
Crystalline Polymers ◽  
Large Pore ◽  
Large Pore Size

Three-dimensional (3D) covalent organic frameworks (COFs) are excellent porous crystalline polymers for numerous applications, but their building units and topological nets have been limited. Herein we report the first 3D large-pore COF with <b>stp</b> topology constructed with a 6-connected triptycene-based monomer. The new COF (termed JUC-564) has high surface area (up to 3300 m<sup>2 </sup>g<sup>-1</sup>), the largest pore (43 Å) among 3D COFs, and record-breaking low density in crystalline materials (0.108 g cm<sup>-3</sup>). The large pore size of JUC-564 is confirmed by the incorporation of a large protein. This study expands the structural varieties of 3D COFs as well as their applications for adsorption and separation of large biological molecules.

In Situ microscopy of the anodic etching of silicon

1995 ◽  
Vol 53 ◽  
pp. 232-233
Author(s):  
Frances M. Ross ◽  
Peter C. Searson
Keyword(s):  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Selective Etching ◽  
Silicon On Insulator ◽  
Second Phase ◽  
Porous Layers ◽  
New Class ◽  
Porous Semiconductors

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.

Electron holography of catalysts

1995 ◽  
Vol 53 ◽  
pp. 416-417
Author(s):  
A. K. Datye ◽  
D. S. Kalakkad ◽  
L. F. Allard ◽  
E. Völkl
Keyword(s):  
Heterogeneous Catalysts ◽  
High Surface ◽  
High Surface Area ◽  
Atomic Scale ◽  
Nano Particles ◽  
Phase Image ◽  
Electron Holography ◽  
Specimen Thickness ◽  
Phase Information ◽  
Particle Structure

The active phase in heterogeneous catalysts consists of nanometer-sized metal or oxide particles dispersed within the tortuous pore structure of a high surface area matrix. Such catalysts are extensively used for controlling emissions from automobile exhausts or in industrial processes such as the refining of crude oil to produce gasoline. The morphology of these nano-particles is of great interest to catalytic chemists since it affects the activity and selectivity for a class of reactions known as structure-sensitive reactions. In this paper, we describe some of the challenges in the study of heterogeneous catalysts, and provide examples of how electron holography can help in extracting details of particle structure and morphology on an atomic scale.Conventional high-resolution TEM imaging methods permit the image intensity to be recorded, but the phase information in the complex image wave is lost. However, it is the phase information which is sensitive at the atomic scale to changes in specimen thickness and composition, and thus analysis of the phase image can yield important information on morphological details at the nanometer level.

Structure and composition of metal particles in Pt-Sn/Al2O3 bimetallic catalysts

1990 ◽  
Vol 48 (4) ◽  
pp. 278-279
Author(s):  
A. Sachdev ◽  
J. Schwank
Keyword(s):  
Bimetallic Catalysts ◽  
Bimetallic Catalyst ◽  
Size Structure ◽  
High Surface ◽  
High Surface Area ◽  
Metal Particles ◽  
Alloy Formation ◽  
Particle Size Range ◽  
Oxide Supports ◽  
Petroleum Fractions

Platinum - tin bimetallic catalysts have been primarily utilized in the chemical industry in the catalytic reforming of petroleum fractions. In this process the naphtha feedstock is converted to hydrocarbons with higher octane numbers and high anti-knock qualities. Most of these catalysts contain small metal particles or crystallites supported on high surface area insulating oxide supports. The determination of the structure and composition of these particles is crucial to the understanding of the catalytic behavior. In a bimetallic catalyst it is important to know how the two metals are distributed within the particle size range and in what way the addition of a second metal affects the size, structure and composition of the metal particles. An added complication in the Pt-Sn system is the possibility of alloy formation between the two elements for all atomic ratios.

Intercalation of First Row Transition Metals inside Covalent-Organic Frameworks (COF): a Strategy to Fine Tune the Electronic Properties of Porous Crystalline Materials

2018 ◽  
Author(s):  
Srimanta Pakhira ◽  
Jose Mendoza-Cortes
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Electronic Properties ◽  
High Surface ◽  
Electronic Devices ◽  
High Surface Area ◽  
Main Role ◽  
Covalent Organic Frameworks ◽  
Porous Network ◽  
Crystalline Materials

<div>Covalent organic frameworks (COFs) have emerged as an important class of nano-porous crystalline materials with many potential applications. They are intriguing platforms for the design of porous skeletons with special functionality at the molecular level. However, despite their extraordinary properties, it is difficult to control their electronic properties, thus hindering the potential implementation in electronic devices. A new form of nanoporous material, COFs intercalated with first row transition metal is proposed to address this fundamental drawback - the lack of electronic tunability. Using first-principles calculations, we have designed 31 new COF materials <i>in-silico</i> by intercalating all of the first row transition metals (TMs) with boroxine-linked and triazine-linked COFs: COF-TM-x (where TM=Sc-Zn and x=3-5). This is a significant addition considering that only 187 experimentally COFs structures has been reported and characterized so far. We have investigated their structure and electronic properties. Specifically, we predict that COF's band gap and density of states (DOSs) can be controlled by intercalating first row transition metal atoms (TM: Sc - Zn) and fine tuned by the concentration of TMs. We also found that the $d$-subshell electron density of the TMs plays the main role in determining the electronic properties of the COFs. Thus intercalated-COFs provide a new strategy to control the electronic properties of materials within a porous network. This work opens up new avenues for the design of TM-intercalated materials with promising future applications in nanoporous electronic devices, where a high surface area coupled with fine-tuned electronic properties are desired.</div>

Tenacious Mass Transfer Limitations Drive Catalytic Selectivity during Electrochemical Carbon Dioxide Reduction

2019 ◽  
Author(s):  
Kailun Yang ◽  
Recep Kas ◽  
Wilson A. Smith
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Catalyst Layer ◽  
Active Surface ◽  
Active Surface Area ◽  
High Concentration ◽  
Copper Electrodes ◽  
Surface Enhanced ◽  
Local Current

<p>This study evaluated the performance of the commonly used strong buffer electrolytes, i.e. phosphate buffers, during CO<sub>2</sub> electroreduction in neutral pH conditions by using in-situ surface enhanced infrared absorption spectroscopy (SEIRAS). Unfortunately, the buffers break down a lot faster than anticipated which has serious implications on many studies in the literature such as selectivity and kinetic analysis of the electrocatalysts. Increasing electrolyte concentration, surprisingly, did not extend the potential window of the phosphate buffers due to dramatic increase in hydrogen evolution reaction. Even high concentration phosphate buffers (1 M) break down within the potentials (-1 V vs RHE) where hydrocarbons are formed on copper electrodes. We have extended the discussion to high surface area electrodes by evaluating electrodes composed of copper nanowires. We would like highlight that it is not possible to cope with high local current densities on these high surface area electrodes by using high buffer capacity solutions and the CO<sub>2</sub> electrocatalysts are needed to be evaluated by casting thin nanoparticle films onto inert substrates as commonly employed in fuel cell reactions and up to now scarcely employed in CO<sub>2</sub> electroreduction. In addition, we underscore that normalization of the electrocatalytic activity to the electrochemical active surface area is not the ultimate solution due to concentration gradient along the catalyst layer.This will “underestimate” the activity of high surface electrocatalyst and the degree of underestimation will depend on the thickness, porosity and morphology of the catalyst layer. </p> <p> </p>

Activated carbon from molasses efficiency for Cr(VI), Pb(II) and Cu(II) adsorption: A mechanistic study

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Activated Carbon ◽  
Phosphoric Acid ◽  
Sugar Industry ◽  
Chemical Activation ◽  
High Surface ◽  
High Surface Area ◽  
Mechanistic Study ◽  
Acid Mixture ◽  
Maximum Adsorption Capacity ◽  
Good Potential

Activated carbon was prepared from molasses, which are natural precursors of vegetable origin resulting from the sugar industry. A simple elaboration process, based on chemical activation with phosphoric acid, was proposed. The final product, prepared by activation of molasses/phosphoric acid mixture in air at 500°C, presented high surface area (more than 1400 m2/g) and important maximum adsorption capacity for methylene blue (625 mg/g) and iodine (1660 mg/g). The activated carbon (MP2(500)) showed a good potential for the adsorption of Cr(VI), Cu(II) and Pb(II) from aqueous solutions. The affinity for the three ions was observed in the following order Cu2+ Cr6+ Pb2+. The process is governed by monolayer adsorption following the Langmuir model, with a correlation coefficient close to unity.

Functionalized Nano-graphene Oxide as Multi-modal Clinic for Effective Drug Delivery

2017 ◽  
Vol 10 (4) ◽  
pp. 3768-3771
Author(s):  
Soumitra Satapathi ◽  
Rutusmita Mishra ◽  
Manisha Chatterjee ◽  
Partha Roy ◽  
Somesh Mohapatra
Keyword(s):  
Drug Delivery ◽  
Graphene Oxide ◽  
Cancer Cell ◽  
High Surface ◽  
High Surface Area ◽  
Cancer Cell Line ◽  
Xrd Analysis ◽  
Graphene Derivatives ◽  
Nano Graphene

Nano-materials based drug delivery modalities to specific organs and tissues has become one of the critical endeavors in pharmaceutical research. Recently, two-dimensional graphene has elicited considerable research interest because of its potential application in drug delivery systems. Here we report, the drug delivery applications of PEGylated nano-graphene oxide (nGO-PEG), complexed with a multiphoton active and anti-cancerous diarylheptanoid drug curcumin. Specifically, graphene-derivatives were used as nanovectors for the delivery of the hydrophobic anticancer drug curcumin due to its high surface area and easy surface functionalization. nGO was synthesized by modified Hummer’s method and confirmed by XRD analysis. The formation of nGO, nGO-PEG and nGO-PEG-Curcumin complex were monitored through UV-vis, IR spectroscopy. MTT assay and AO/EB staining found that nGO-PEG-Curcumin complex afforded highly potent cancer cell killing in vitro with a human breast cancer cell line MCF7.

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