Enzymatic oxidation of tert-butylcatechol in the presence of sulfhydryl compounds: Application to the amperometric detection of penicillamine

Angel Alberto Jesus Torriero, Hugo D Piola, Noelia A Martinez, Nancy V Panini, Julio Raba, Juana J Silber

Research output: Contribution to journalArticleResearchpeer-review

34 Citations (Scopus)

Abstract

The high sensitivity that can be attained using an enzymic system and mediated by 4-tert-butylcatechol (4-TBC) has been verified by online interfacing of a rotating biosensor and continuous flow/stopped-flow/continuous-flow processing. Horseradish peroxidase, HRP, [EC 1.11.1.7], immobilized on a rotating disk, in presence of hydrogen peroxide catalyzed the oxidn. of 4-TBC, whose back electrochem. redn. was detected on glassy carbon electrode surface at -150 mV. Thus, when penicillamine (PA) was added to the soln., these thiol-contg. compds. participate in Michael type addn. reactions with 4-TBC to form the corresponding thioquinone derivs., decreasing the peak current obtained proportionally to the increase of its concn. The highest response for PA was obtained around pH 7. This method could be used to det. PA concn. in the range 0.02-80 micro M (r = 0.998). The detn. of PA was possible with a limit of detection of 7 nM, in the processing of as many as 50 samples per h. The HRP-rotating biosensor was successfully applied to the detn. of PA in pharmaceutical formulations. [on SciFinder (R)]
Original languageEnglish
Pages (from-to)1198 - 1204
Number of pages7
JournalTalanta
Volume71
Issue number3
DOIs
Publication statusPublished - 2007
Externally publishedYes

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