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Biomedical subjects

Takuya Nakanishi

Publications and source records attributed to Takuya Nakanishi.

5 recordsLinked to original sources

Enantioselectivity of redox reaction of DOPA at the gold electrode modified with a self-assembled monolayer of homocysteine.

The enantioselectivity of the self-assembled monolayer (SAM) of homocysteine formed on the (111)-oriented gold surface was investigated. We analyzed the redox behavior of 3,4-dihydroxyphenylalanine (DOPA), which is an electrochemically active chiral molecule, by means of cyclic voltammetry at a gold electrode modified with one enantiomeric form of homocysteine. It was demonstrated that the homocysteine SAM of one enantiomeric form blocked the redox reaction of only one enantiomer of DOPA, with cross inversion for the other enantiomer, in acidic solution.

Biosensing Techniques↗

Synthesis of magnetic nanoparticles and their application to bioassays.

Magnetic nanoparticles have been attracting much interest as a labeling material in the fields of advanced biological and medical applications such as drug delivery, magnetic resonance imaging, and array-based assaying. In this review, synthesis of iron oxide magnetic nanoparticles via a reverse micelle system and modification of their surface by an organosilane agent are discussed. Furthermore, as a practical biological assay system, the magnetic detection of biomolecular interactions is demonstrated by using the combination of a patterned substrate modified with a self-assembled monolayer and the magnetic nanoparticles.

Biotin↗

Chiral discrimination between thalidomide enantiomers using a solid surface with two-dimensional chirality.

Chiral discrimination between thalidomide enantiomers was achieved using the self-assembled monolayer (SAM) of an atropisomeric compound, 1,1'-binaphthalene-2,2'-dithiol (BNSH), which takes a two-dimensional chiral arrangement on gold(111) surface. Interestingly, an "all-or-none" type enantioselectivity appears; one enantiomeric form of BNSH SAM allows the adsorption of only one enantiomer of thalidomide. In addition, the response of a racemic SAM of BNSH was revealed to be one-half of that caused by pure enantiomeric SAM.

Carboxylic Acids↗

Enantioselective adsorption of phenylalanine onto self-assembled monolayers of 1,1'binaphthalene-2,2'-dithiol on gold.

Self-assembled monolayer of atropisomeric compound, 1,1'-binaphthalene-2,2'-dithiol (BNSH), provides a field for chiral discrimination. The two-dimensional chiral arrangement with screw-like units, each of which is composed of three BNSH molecules, plays an important role in the enantioselectivity of adsorption of phenylalanine, as revealed by a quartz crystal microbalance technique.

Adsorption↗