Electrospinning: a fascinating fiber fabrication technique.

Zinc oxide can be called a multifunctional material thanks to its unique physical and chemical properties. The first part of this paper presents the most important methods of preparation of ZnO divided into metallurgical and chemical methods. The mechanochemical process, controlled precipitation, sol-gel method, solvothermal and hydrothermal method, method using emulsion and microemulsion enviroment and other methods of obtaining zinc oxide were classified as chemical methods. In the next part of this review, the modification methods of ZnO were characterized. The modification with organic (carboxylic acid, silanes) and inroganic (metal oxides) compounds, and polymer matrices were mainly described. Finally, we present possible applications in various branches of industry: rubber, pharmaceutical, cosmetics, textile, electronic and electrotechnology, photocatalysis were introduced. This review provides useful information for specialist dealings with zinc oxide.

Zinc Oxide-From Synthesis to Application: A Review.

Nanotechnology involves the production, manipulation and use of materials ranging in size from less than a micron to that of individual atoms. Although nanomaterials may be synthesized using chemical approaches, it is now possible to include the use of biological materials. In this review, we critically assess the role of microorganisms and plants in the synthesis of nanoparticles.

Biosynthesis of nanoparticles: technological concepts and future applications

New materials of emerging technological importance are single-walled carbon nanotubes (SWCNTs). Because SWCNTs will be used in commercial products in huge amounts, their effects on human health and the environment have been addressed in several studies. Inhalation studies in vivo and submerse applications in vitro have been described with diverging results. Why some indicate a strong cytotoxicity and some do not is what we report on here. Data from A549 cells incubated with carbon nanotubes fake a strong cytotoxic effect within the MTT assay after 24 h that reaches roughly 50%, whereas the same treatment with SWCNTs, but detection with WST-1, reveals no cytotoxicity. LDH, FACS-assisted mitochondrial membrane potential determination, and Annexin-V/PI staining also reveal no cytotocicity. SWCNTs appear to interact with some tetrazolium salts such as MTT but not with others (such as WST-1, INT, XTT). This interference does not seem to affect the enzymatic reaction but lies rather in the insoluble nature of MTT-formazan. Our findings strongly suggest verifying cytotoxicity data with at least two or more independent test systems for this new class of materials (nanomaterials). Moreover, we intensely recommend standardizing nanotoxicological assays with regard to the material used: there is a clear need for reference materials. MTT-formazan crystals formed in the MTT reaction are lumped with nanotubes and offer a potential mechanism to guide bioremediation and clearance for SWCNTs from "contaminated" tissue. SWCNTs are good supporting materials for tissue growth, as attachment of focal adhesions and connections to the cytoskeleton suggest.

Oops they did it again! Carbon nanotubes hoax scientists in viability assays.

Immobilization strategies to develop enzymatic biosensors

Nanotechnology and biosensors

https://www.cell.com/trends/biotechnology/pdf/S0167-7799(04)00078-2.pdf

Using electropolymerized non-conducting polymers to develop enzyme amperometric biosensors

The glucose biosensors were prepared by the electropolymerization of the non-conductive polymer, Poly(o-phenylenediamine), onto a planar screen-printed electrode. A fabrication procedure was performed to decrease the waste of expensive enzyme. The amperometric glucose response was measured by the potensiostating of the prepared glucose biosensors at a potential of 0.3 V with ferrocene as mediator. Results show that the obtained biosensors have a linear range up to 25 mM glucose, fast response time (100s) and high sensitivities (16.6 nA/mM). Also, the effects of applied potential and sweeping number of Cyclic voltammograms for electropolymerization were systematically investigated and optimal values were recorded.

Wu Xiaohua

Papers

Nanotechnology and biosensors

Using electropolymerized non-conducting polymers to develop enzyme amperometric biosensors

Construction of a Glucose Biosensor by Immobilizing Glucose Oxidase within a Poly(o- phenylenediamine) Covered Screen-printed Electrode