Monitoring beta-galactosidase activity by means of scanning electrochemical microscopy

Chuan Zhao, Jatin Kumar Sinha, Charles Ajith Wijayawardhana, Gunther Wittstock

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40 Citations (Scopus)


The activity of beta-galactosidase from Escherichia coli was characterized by scanning electrochemical microscopy (SECM). beta-Galactosidase microspots were patterned by immobilizing biotin-labelled beta-galactosidase on streptavidin-coated paramagnetic beads and depositing the beads as microscopic microspots on a hydrophobic surface. The enzyme activity was mapped with SECM in the gene ration-collection mode by monitoring the oxidation of p-aminophenol formed in the galactosidase-catalyzed hydrolysis at the surface of the beads. The electrochemical properties of the enzyme substrate and product were studied with a platinum ultramicroelectrode, and the imaging conditions were optimised. The suitability of the procedure for forming beta-galactosidase microspot arrays and the capability of SECM to resolve enzyme activity over individual enzyme microspots were demonstrated. (C) 2003 Elsevier B.V. All rights reserved.
Original languageEnglish
Pages (from-to)83 - 91
Number of pages9
JournalJournal of Electroanalytical Chemistry
Publication statusPublished - 2004
Externally publishedYes

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