fabrication-an-optical-cell-dryer-for-spectroscopic-analysis

Fabrication of an Optical Cell Dryer for the Spectroscopic Analysis Cells

Optical cells, which are experimental instruments, are small, square tubes sealed on one side. A sample is placed in this tube, and a measurement is ...

fabrication-microscope-stage-for-vertical-observation-with

Fabrication of Microscope Stage for Vertical Observation with Temperature Control Function

Samples are usually placed onto a horizontal microscope stage for microscopic observation. However, to observe the influence of gravity on a sample or ...

Tokyo University of Science

Tokyo University of science

We detected antioxidant activity of catechin, one of the main components of tea, using SWNTs surface coated with two different biomolecules. Compared to coating with DNA already reported, it can hardly be detected when coated with carboxymethyl cellulose. For nanobiosensing using SWNTs, its sensitivity is not determined only by SWNTs, we found that biomolecules covering the surface are extremely important. In this experiment, we measured the near-infrared absorption spectra of SWNTs coated separately with two different water-soluble polymers; DNA (double-stranded DNA-SWNT complexes) and carboxymethyl cellulose (CMC, CMC-SWNT complexes), and uncovered the differences in their antioxidant properties against the flavonoid catechin. Each dispersion was oxidized with HO at 0.03% (final concentration), following which catechin solutions were added to reduce the samples. Our results showed that the magnitude of the change in the absorbance spectra for dsDNA-SWNT complexes in response to oxidation and reduction was superior to that for CMC-SWNT complexes. The CMC-SWNT complexes exhibited almost no change in their spectra even though the same SWNT powder (produced by the high-pressure carbon monoxide (HiPco) method) was used. On the other hand, when (6, 5)-enriched SWNT powder produced by the ComoCat method was used, no significant change in the absorbance was observed, even though (6, 5)-enriched SWNTs are frequently used for nanobiosensing. Our results revealed that both the SWNT chirality and type of polymer for wrapping SWNTs are important factors for establishing nanobiosensing methods utilizing SWNTs.

ArticleTotal : 2	Year
Publication title	2019
Publication title Cited by 3	2019

Yuji Matsukawa

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