Recognition of Bile Acids at Cyclodextrin-Modified Gold Electrodes

Egawa, Yuya; Ishida, Yasuhiro; Yamauchi, Akiyo; Anzai, Jun Ichi; Suzuki, I.

doi:10.2116/analsci.21.361

Cited by 7 publications

(10 citation statements)

References 31 publications

(57 reference statements)

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“…Rewinding of a Double Helix of Oligoresorcinol. 1-Aminoadamantane hydrochloride ( Ad ), which forms a strong inclusion complex with β-CD, 8e-h was then added to the [3]pseudorotaxane 9merH ·(β-CD) 2 solution for the purpose of inhibiting the helicase-like activity of β-CD (Figure ). Upon the addition of an equimolar amount of Ad to β-CD, the 1 H NMR signals of the 9merH shifted upfield and became almost the same broadened signals as observed for the original double helix of the 9merH , and the methylene and methine signals of Ad significantly shifted downfield compared to those of the free Ad in D 2 O (Figure A, (c) and (e)).…”

Section: Resultsmentioning

confidence: 99%

“…The further addition of β-CD brought about the unwinding of the double helix of the 9merH , as evidenced by the downfield shifts of the 1 H NMR signals of the 9merH moiety (Figure A, (d)), the hyperchromic shift in the absorption spectrum, and the reappearance of the identical induced circular dichroism (Figure B, (d)). In contrast to β-CD, the γ-CD wheels of the 9merH ·(γ-CD) 2 were only slightly removed by the addition of Ad probably due to the lower affinity of Ad to γ-CD, as indicated by the absorption, circular dichroism, and 1 H NMR spectra (Supporting Information). 8e-h…”

Section: Resultsmentioning

confidence: 99%

“…We now report a supramolecular approach to control the reversible unwinding and rewinding of the oligoresorcinol double helix in water using cyclodextrins (CDs) as receptors with a helicase-like activity together with an adamantane as its inhibitor. We anticipated that CDs, rigid, well-defined cylindrical macrocycles with a hydrophobic chiral cavity, would unwind the oligoresorcinol double helix to form a (pseudo)rotaxane, in which a single-stranded oligoresorcinol is threaded into the CD wheels; the subsequent addition of an adamantane will regenerate the double helix because the encapsulated single-stranded oligoresorcinol is expelled from the CD cavity (Figures A and 2C) 1 (A) Schematic illustration of the unwinding of the double helix of 9merH by β-CD and the subsequent formation of 9merH ·(β-CD) 2 .…”

Section: Introductionmentioning

confidence: 99%

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Supramolecular Control of Unwinding and Rewinding of a Double Helix of Oligoresorcinol Using Cyclodextrin/Adamantane System

2006

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The double helix of the oligoresorcinol nonamer formed in water was unwound by beta-cyclodextrin (beta-CD), and the resulting single strands of the nonamer threaded the beta-CD to form a twisted [3]-pseudorotaxane with a controlled helicity. Upon the addition of an adamantane, the single strand of the oligoresorcinol nonamer was expelled out of the beta-CD wheels, thus regenerating the double helix. This supramolecularly controlled, reversible unwinding and rewinding of the double helix is unique and can be readily monitored by spectroscopic techniques.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Supramolecular Control of Unwinding and Rewinding of a Double Helix of Oligoresorcinol Using Cyclodextrin/Adamantane System

2006

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“…CV experiments were performed on various redox compounds (K 3 [Fe(CN) 6 ], [Ru(NH3) 6 ]Cl 3 , and hydroxymethylferrocene) (Figure b–d). The electrochemical response of [Fe(CN) 6 ] 3−/4− is strongly affected by the charge and state on the electrode surface . When the electrode surface has a negative charge, it repels [Fe(CN) 6 ] 3−/4− , inhibiting the electrochemical response.…”

Section: Figurementioning

confidence: 99%

Carbon Nanotube Immobilized Electrode Using Amphiphilic Phospholipid Polymer with Anti‐fouling and Dispersion Property for Electrochemical Analysis

Sato

Konno

2020

Electroanalysis

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A carbon nanotube (CNT)‐modified electrode was fabricated by dropping a dispersion of multi‐walled CNTs in water‐soluble and amphiphilic phospholipid polymer with both dispersing ability and anti‐biofouling property onto a Au electrode. A poly(2‐methacryloyloxyethyl phosphorylcholine‐co‐n‐butyl methacrylate) (PMB) composed from 50 mol% of 2‐methacryloxylethyl phosphorylcholine and 50 mol% of n‐butyl methacrylate (PMB50) was used as dispersing reagent for CNTs. The dispersion of water‐insoluble material by PMB50 and its antifouling effects in electrochemical analysis were investigated. The CNT‐modified electrode showed an anodic peak potential that was shifted negatively and an increase in the current value for the electrolytic oxidation of nicotinamide adenine dinucleotide. In addition, the charge on PMB50 did not inhibit the electrochemical reaction of the redox compounds K3[Fe(CN)6], [Ru(NH3)6]Cl3, and hydroxymethylferrocene. Cyclic voltammetry of K3[Fe(CN)6] in 4 % bovine serum albumin (BSA) using a bare Au electrode, the anodic peak current was reduced to 47 % of that without BSA. In contrast, the antifouling effect of the PMB50‐coated electrode meant that the current was only reduced to 70 % of that without BSA.

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“…Moreover, enzymatic reactions are applicable to only a limited number of substances. Therefore, enzyme-free electrochemical sensors, such as metal oxide-coated electrodes, 10,11) supramolecular host/guest compound-modified electrodes, 12) and phenylboronic acid-modified electrodes, 13,14) have also been developed.…”

Section: Introductionmentioning

confidence: 99%

Nitroxyl Radical/Copper-Catalyzed Electrooxidation of Alcohols and Amines at Low Potentials

Sugiyama

Sasano

Komatsu

et al. 2021

CHEMICAL & PHARMACEUTICAL BULLETIN

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Nitroxyl radicals, such as 2,2,6,6-tetramethylpiperidine N-oxyl (TEMPO), can catalyze the electrochemical oxidation of alcohols and amines. Because the oxidation current obtained in this process depends on the concentration of alcohols and amines, this process can be applied to their sensing. However, the relatively high oxidation potentials required by nitroxyl radicals can induce interfering oxidation currents from various reductive substances in biological samples, which affects the accuracy of analyte measurements. In this study, we examined the electrooxidation of alcohols and amines at a low potential by applying cooperative oxidation catalysis using a nitroxyl radical and a copper salt. Nortropine N-oxyl (NNO), which showed higher catalytic activity than TEMPO was used as the nitroxyl radical. An increase in the oxidation current was observed at the low potential, and this increase depended on the alcohol concentration. In the case of the electrooxidation of amines, a positive correlation between oxidation current and amine concentration was observed at low amine concentrations. Therefore, low-potential cooperative catalysis can be applied to alcohol and amine electrooxidation for the development of accurate sensors suitable for clinical settings.

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Recognition of Bile Acids at Cyclodextrin-Modified Gold Electrodes

Cited by 7 publications

References 31 publications

Supramolecular Control of Unwinding and Rewinding of a Double Helix of Oligoresorcinol Using Cyclodextrin/Adamantane System

Supramolecular Control of Unwinding and Rewinding of a Double Helix of Oligoresorcinol Using Cyclodextrin/Adamantane System

Carbon Nanotube Immobilized Electrode Using Amphiphilic Phospholipid Polymer with Anti‐fouling and Dispersion Property for Electrochemical Analysis

Nitroxyl Radical/Copper-Catalyzed Electrooxidation of Alcohols and Amines at Low Potentials

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