The role of incipient hydrous oxides in the oxidation of glucose and some of its derivatives in aqueous media

✍ Scribed by L.D. Burke; T.G. Ryan

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 784 KB
• Volume: 37
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(92)87008-n

✦ Synopsis

Gold m aqueous media, with its extensive workmg range apparently devoid of comphcatrons due to chemisorbed hydrogen and oxygen species, 1s frequently considered as the ideal electrode system for fundamental mvestlgations m electrochemistry However, tins system displays agmficant electrocatalytrc actlvlty m base, an effect that has been attnbuted to a phenomenon known as pre-monolayer oxidation Glucose oxidation at gold m base commences at cu 0 15 V (rhe), the reaction (evidently confined at low potent& to the aldehyde group) bemg mediated by an Au(I) mclpient hydrous oxide species m agreement with thrs approach to electrocatalysis the reactlon of other specs, eg formaldehyde and hmethylamme borane ondation and nitrate Ion reduction, commences m the same regon The alcohol groups m glucose (and Its derivatives) are more resIstant to oxidation, they only commence reaction above 0 65 V (rhe) where a different mediator, an Au(II1) hydrous oxide specks, IS present at the interface The glucose oxidation rate, which IS of slgmficant interest m the blosensor area, decreases as the pH of the solution IS reduced