Enhanced and Prolonged Activity of Enzymes Adsorbed on TEMPO-Oxidized Cellulose Nanofibers.

2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofibers (TOCNs) have a width of about 4 nm and a very large specific surface area. TOCN is a negatively charged bionanomaterial having carboxy groups on the surface and promising physical properties. In particular, TOCN can be used as an adsorbent for biomolecules for biotechnological applications, but the adsorption behavior of biomolecules on the TOCN surface requires investigation.

TEMPO-oxidized cellulose nanofiber (TOCN) decorated macroporous silica particles: Synthesis, characterization, and their application in protein adsorption.

Effective protein adsorption has attracted attention for broad application in the biomedical field. In this study, we introduce the synthesis of a TEMPO-oxidized cellulose nanofiber (TOCN) decorated macroporous SiO (TOCN@macroporous SiO) particle and its protein adsorption performance. The TOCN@macroporous SiO particles have a unique cellulose nanofiber network structure on the macroporous, highly-negative zeta potential (-62 ± 2 mV) and high surface area (30.

Structure retention of proteins interacting electrostatically with TEMPO-oxidized cellulose nanofiber surface.

In this study, we evaluated the adsorption of proteins to 2,2,6,6-tetramethylpiperidine-1-oxyl oxidized cellulose nanofibers (TOCNs) and their structures on the TOCN surface. TOCNs derived from bleached pulp are as thin as 4 nm and have a very high specific surface area and a high density of surface carboxyl groups. The adsorption of two model proteins (lysozyme (Lyz) and bovine serum albumin (BSA)), which is driven by electrostatic attraction between the positively charged proteins and the negatively charged TOCN surface bearing ionized carboxyl groups, is demonstrated to occur only at pH values below their isoelectric points.

Cellulose Nanofibers as a Module for Paper-Based Microfluidic Analytical Devices: Labile Substance Storage, Processability, and Reaction Field Provision and Control.

While basic concepts of paper-based microfluidic analytical devices (μPADs) have appeared considerably, elemental technology development is worth working from different specialized points of view. Herein, we show that 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-oxidized cellulose nanofiber (TOCN) can be reasonably used as a module of μPADs; we adopted a biochemical reaction of indigo formation by oxidation of indoxyl acetate (IDA) via its hydrolysis with acetylcholinesterase (AChE) as an example. First, we demonstrate that TOCN stably stores unstable AChE and IDA when dried and acts as a biochemical reaction field when wet.

Broadly tunable subterahertz emission from internal branches of the current-voltage characteristics of superconducting Bi2Sr2CaCu2O(8+δ) single crystals.

Continuous, coherent subterahertz radiation arises when a dc voltage is applied across a stack of the many intrinsic Josephson junctions in a Bi2Sr2CaCu2O(8+δ) single crystal. The active junctions produce an equal number of I-V characteristic branches. Each branch radiates at a slightly tunable frequency obeying the Josephson relation.

Asymmetric Michael addition reactions of 2-silyloxyfurans catalyzed by binaphthyldiimine-Ni(II) complexes.

N,N'-Bis(2-quinolylmethylene)-1,1'-binaphthyl-2,2'-diamine-Ni(II) complex and analogous complexes were found to be efficient chiral Lewis acid catalysts for the asymmetric Michael addition reactions between 2-silyloxyfurans and 3-alkenoyl-2-oxazolidinones, for which asymmetric inductions of up to 97% ee were obtained.